PATH Documentation > WebObjects 4.5 > EOAdaptor Reference

EOSQLExpression

Inherits from: NSObject

Package: com.apple.yellow.eoaccess

Class Description

EOSQLExpression is an abstract superclass that defines how to build SQL statements for adaptor channels. You don't typically use instances of EOSQLExpression; rather, you use EOSQLExpression subclasses written to work with a particular RDBMS and corresponding adaptor. A concrete subclass of EOSQLExpression overrides many of its methods in terms of the query language syntax for its specific RDBMS. EOSQLExpression objects are used internally by the Framework, and unless you're creating a concrete adaptor, you won't ordinarily need to interact with EOSQLExpression objects yourself. You most commonly create and use an EOSQLExpression object when you want to send an SQL statement directly to the server. In this case, you simply create an expression with the EOSQLExpression static method expressionForString, and send the expression object to an adaptor channel using EOAdaptorChannel's evaluateExpression method.

For more information on using EOSQLExpressions, see the following sections:

Constants

EOSQLExpression defines the following String constants.

Constant	Description
`BindVariableNameKey`	The key for the name of a bind variable in a bind variable dictionary.
`BindVariablePlaceHolderKey`	A key for use in bind variable dictionaries. The corresponding value is the placeholder string to be used in SQL.
`BindVariableAttributeKey`	A key for use in bind variable dictionaries. The corresponding value is the attribute that uses the bind variable.
`BindVariableValueKey`	A key for use in bind variable dictionaries. The corresponding value is the value for the bind variable.
`CreateTablesKey`	Key for use in options dictionaries. A corresponding value of "YES" indicates that the EOSQLExpression should generate SQL to create tables.
`DropTablesKey`	Key for use in options dictionaries. A corresponding value of "YES" indicates that the EOSQLExpression should generate SQL to drop tables.
`CreatePrimaryKeySupportKey`	Key for use in options dictionaries. A corresponding value of "YES" indicates that the EOSQLExpression should generate SQL to create primary key support.
`DropPrimaryKeySupportKey`	Key for use in options dictionaries. A corresponding value of "YES" indicates that the EOSQLExpression should generate SQL to drop primary key support.
`PrimaryKeyConstraintsKey`	Key for use in options dictionaries. A corresponding value of "YES" indicates that the EOSQLExpression should generate SQL to create primary key constraints.
`ForeignKeyConstraintsKey`	Key for use in options dictionaries. A corresponding value of "YES" indicates that the EOSQLExpression should generate SQL to create foreign key constraints.
`CreateDatabaseKey`	Key for use in options dictionaries. A corresponding value of "YES" indicates that the EOSQLExpression should generate SQL to create a database.
`DropDatabaseKey`	Key for use in options dictionaries. A corresponding value of "YES" indicates that the EOSQLExpression should generate SQL to drop a database.
`AllowsNullKey`	Key for use in change dictionaries. A corresponding value indicates that the column's allows NULL value should be changed from.
`ColumnNameKey`	Key for use in change dictionaries. A corresponding value indicates that the column's allows NULL value should be changed from.
`ExternalNameKey`	Key for use in change dictionaries. A corresponding value indicates that the column's allows NULL value should be changed from.
`ExternalTypeKey`	Key for use in change dictionaries. A corresponding value indicates that the column's allows NULL value should be changed from.
`NameKey`	Key for use in change dictionaries. A corresponding value indicates the old value of the table or column.
`PrecisionKey`	Key for use in change dictionaries. A corresponding value indicates the value a column's precision should be changed from.
`RelationshipsKey`	Key for use in change dictionaries. The corresponding value is a dictionary of relationships which have been modified since the last time the model and schema were sychronized. For more information see "The Change Dictionary" .
`ScaleKey`	Key for use in change dictionaries. A corresponding value indicates the value the column's scale should be changed from.
`WidthKey`	Key for use in change dictionaries. A corresponding value indicates the value the column's width should be changed from.

Method Types

Constructors

EOSQLExpression

Creating an EOSQLExpression object

selectStatementForAttributes

insertStatementForRow

updateStatementForRow

deleteStatementWithQualifier

expressionForString

Building SQL Expressions

prepareSelectExpressionWithAttributes

prepareInsertExpressionWithRow

prepareUpdateExpressionWithRow

prepareDeleteExpressionForQualifier

setStatement

statement

Generating SQL for attributes and values

formatSQLString

formatValueForAttribute

formatStringValue

sqlStringForValue

sqlStringForAttributeNamed

sqlStringForAttribute

sqlStringForAttributePath

sqlStringForNumber

sqlStringForString

Generating SQL for names of database objects

sqlStringForSchemaObjectName

setUseQuotedExternalNames

useQuotedExternalNames

externalNameQuoteCharacter

Generating an attribute list

addSelectListAttribute

addInsertListAttribute

addUpdateListAttribute

appendItemToListString

listString

Generating a value list

addInsertListAttribute

addUpdateListAttribute

valueList

Generating a table list

tableListWithRootEntity

aliasesByRelationshipPath

Generating the join clause

joinExpression

addJoinClause

assembleJoinClause

joinClauseString

Generating a search pattern

sqlPatternFromShellPattern

sqlPatternFromShellPatternWithEscapeCharacter

Generating a relational operator

sqlStringForSelector

Accessing the where clause

whereClauseString

Generating an order by clause

addOrderByAttributeOrdering

orderByString

Accessing the lock clause

lockClause

Assembling a statement

assembleSelectStatementWithAttributes

assembleInsertStatementWithRow

assembleUpdateStatementWithRow

assembleDeleteStatementWithQualifier

Generating SQL for qualifiers

sqlStringForQualifier

sqlStringForConjoinedQualifiers

sqlStringForDisjoinedQualifiers

sqlStringForKeyComparisonQualifier

sqlStringForKeyValueQualifier

sqlStringForNegatedQualifier

Managing bind variables

setUseBindVariables

useBindVariables

addBindVariableDictionary

bindVariableDictionaries

bindVariableDictionaryForAttribute

mustUseBindVariableForAttribute

shouldUseBindVariableForAttribute

Using table aliases

setUseAliases

useAliases

Accessing the entity

entity

Creating a schema generation script

schemaCreationScriptForEntities

schemaCreationStatementsForEntities

appendExpression

createTableStatementsForEntityGroup

createTableStatementsForEntityGroups

dropTableStatementsForEntityGroup

dropTableStatementsForEntityGroups

primaryKeyConstraintStatementsForEntityGroup

primaryKeyConstraintStatementsForEntityGroups

primaryKeySupportStatementsForEntityGroup

primaryKeySupportStatementsForEntityGroups

dropPrimaryKeySupportStatementsForEntityGroup

dropPrimaryKeySupportStatementsForEntityGroups

addCreateClauseForAttribute

columnTypeStringForAttribute

allowsNullClauseForConstraint

foreignKeyConstraintStatementsForRelationship

prepareConstraintStatementForRelationship

createDatabaseStatementsForConnectionDictionary

dropDatabaseStatementsForConnectionDictionary

Synchronizing the database with a model

statementsToUpdateObjectStoreForModel

statementsToUpdateObjectStoreForEntityGroup

statementsToCopyTableNamed

phraseCastingColumnNamed

statementsToRenameTableNamed

statementsToInsertColumnForAttribute

statementsToDeleteColumnNamed

statementsToRenameColumnNamed

statementsToModifyColumnNullRule

statementsToConvertColumnType

isColumnTypeEquivalentToColumnType

statementsToDropForeignKeyConstraintsOnEntityGroup

statementsToDropPrimaryKeyConstraintsOnEntityGroup

statementsToDropPrimaryKeySupportForEntityGroup

statementsToImplementForeignKeyConstraintsOnEntityGroup

statementsToImplementPrimaryKeyConstraintsOnEntityGroup

statementsToImplementPrimaryKeySupportForEntityGroup

Querying about database synchronization support

supportsSchemaSynchronization

supportsDirectColumnCoercion

supportsDirectColumnDeletion

supportsDirectColumnInsertion

supportsDirectColumnNullRuleModification

supportsDirectColumnRenaming

Constructors

EOSQLExpression

public EOSQLExpression(EOEntity anEntity)

Creates a new EOSQLExpression rooted to anEntity.

See Also: entity

Static Methods

appendExpression

public static void appendExpression( EOSQLExpression anSQLExpression, String script)

Append's anSQLExpression's statement to script along with any necessary delimiter. EOSQLExpression's implementation appends the SQL statement for anSQLExpression to script followed by a semicolon and a newline. A subclass of EOSQLExpression only needs to override this method if the delimiter for its database server is different. For example, the Oracle and Informix use the default implementation, whereas the Sybase adaptor appends the word "go" instead of a semicolon.

createDatabaseStatementsForConnectionDictionary

public static NSArray createDatabaseStatementsForConnectionDictionary( NSDictionary connectionDictionary, NSDictionary adminDictionary)

Generates the SQL statements that will create a database (or user, for Oracle) that can be accessed by the provided connection dictionary and administrative connection dictionary.

createTableStatementsForEntityGroup

public static NSArray createTableStatementsForEntityGroup(NSArray entityGroup)

Returns an array of EOSQLExpression objects that define the SQL necessary to create a table for entityGroup, an array of EOEntity objects that have the same externalName. Returns an empty array if entityGroup is null or empty.

EOSQLExpression's implementation does the following:

Creates an EOSQLExpression object.
Sets the expression's entity to the first entity in entityGroup.
Adds a create clause for each Attribute in entityGroup's Entities.
Sets the expression's statement to CREATE TABLE TABLE_NAME (LIST_STRING), where TABLE_NAME is the externalName of the Entity objects in entityGroup and LIST_STRING is the expression's listString.
Adds the expression to an array.
Returns the array.

The following is an example of a CREATE TABLE statement produced by the default implementation:

create table EMPLOYEE (
    EMP_ID      int not null,
    DEPT_ID     int null,
    LAST_NAME   varchar(40) not null,
    PHONE       char(12) null,
    HIRE_DATE   date null,
    SALARY      number(7, 2) null
)

If a subclass's database server's table creation semantics are different, the subclass should override this method or one or more of the following methods as appropriate:

addCreateClauseForAttribute
columnTypeStringForAttribute
allowsNullClauseForConstraint

createTableStatementsForEntityGroups

public static NSArray createTableStatementsForEntityGroups(NSArray entityGroups)

Returns an array of EOSQLExpression objects that define the SQL necessary to create the tables specified in entityGroups. An entity group is an array of Entity objects that have the same externalName, and entityGroups is an array of entity groups. Returns an empty array if entityGroups is null or empty. EOSQLExpression's implementation invokes createTableStatementsForEntityGroup for each entity group in entityGroups and returns an array of all the resulting EOSQLExpressions.

deleteStatementWithQualifier

public static EOSQLExpression deleteStatementWithQualifier( com.apple.yellow.eocontrol.EOQualifier qualifier, Object entity)

Creates and returns an SQL DELETE expression to delete the rows described by qualifier. Creates an instance of EOSQLExpression, initializes it with entity (an EOEntity object), and sends it a prepareDeleteExpressionForQualifier message. Throws an exception if qualifier is null.

The expression created with this method does not use table aliases because Enterprise Objects Framework assumes that all INSERT, UPDATE, and DELETE statements are single-table operations. As a result, all keys in qualifier should be simple key names; no key paths are allowed. To generate DELETE statements that do use table aliases, you must override prepareDeleteExpressionForQualifier to send a setUseAliases(true) message prior to invoking super's version.

dropDatabaseStatementsForConnectionDictionary

public static NSArray dropDatabaseStatementsForConnectionDictionary( NSDictionary connectionDictionary, NSDictionary adminDictionary)

Generates the SQL statements to drop a database (or user, for Oracle).

dropPrimaryKeySupportStatementsForEntityGroup

public static NSArray dropPrimaryKeySupportStatementsForEntityGroup(NSArray entityGroup)

Returns an array of EOSQLExpression objects that define the SQL necessary to drop the primary key generation support for entityGroup, an array of Entity objects that have the same externalName. The drop statement generated by this method should be sufficient to remove the primary key support created by primaryKeySupportStatementsForEntityGroup's statements.

EOSQLExpression's implementation creates a statement of the following form:

drop sequence SEQUENCE_NAME

Where SEQUENCE_NAME is the primaryKeyRootName for the first entity in entityGroup concatenated with "_SEQ" (EMP_ID_SEQ, for example).

If a subclass uses a different primary key generation mechanism or if the subclass's database server's drop semantics are different, the subclass should override this method.

dropPrimaryKeySupportStatementsForEntityGroups

public static NSArray dropPrimaryKeySupportStatementsForEntityGroups(NSArray entityGroups)

Returns an array of EOSQLExpression objects that define the SQL necessary to drop the primary key generation support for the entities specified in entityGroups. An entity group is an array of EOEntity objects that have the same externalName, and entityGroups is an array of entity groups. EOSQLExpression's implementation invokes dropPrimaryKeySupportStatementsForEntityGroup for each entity group in entityGroups and returns an array of all the resulting EOSQLExpressions.

dropTableStatementsForEntityGroup

public static NSArray dropTableStatementsForEntityGroup(NSArray entityGroup)

Returns an array of EOSQLExpression objects that define the SQL necessary to drop the table identified by entityGroup, an array of Entity objects that have the same externalName. The drop statement generated by this method should be sufficient to remove the table created by createTableStatementsForEntityGroup's statements.

EOSQLExpression's implementation creates a statement of the following form:

DROP TABLE TABLE_NAME

Where TABLE_NAME is the externalName of the first entity in entityGroup.

If a subclass's database server's drop semantics are different, the subclass should override this method.

dropTableStatementsForEntityGroups

public static NSArray dropTableStatementsForEntityGroups(NSArray entityGroups)

Returns an array of EOSQLExpression objects that define the SQL necessary to drop the tables for entityGroups. An entity group is an array of Entity objects that have the same externalName, and entityGroups is an array of entity groups. EOSQLExpression's implementation invokes dropTableStatementsForEntityGroup for each entity group in entityGroups and returns an array of all the resulting EOSQLExpressions.

expressionForString

public static EOSQLExpression expressionForString(String string)

Creates and returns an SQL expression for string. string should be a valid expression in the target query language. This method does not perform substitutions or formatting of any kind.

See Also: setStatement

foreignKeyConstraintStatementsForRelationship

public static NSArray foreignKeyConstraintStatementsForRelationship(EORelationship aRelationship)

Returns an array of EOSQLExpression objects that define the SQL necessary to create foreign key constraints for aRelationship. EOSQLExpression's implementation generates statements such as the following:

ALTER TABLE EMPLOYEE ADD CONSTRAINT TO_DEPARTMENT FOREIGN KEY (DEPT_ID)
        REFERENCES DEPARTMENT(DEPT_ID)

It returns an empty array if either of the following are true:

aRelationship spans models (if aRelationship's destinationEntity is in a different model than aRelationship's source entity)
aRelationship is a to-many relationship, or if the inverse relationship of aRelationship is not a to-many. In other words, foreign key constraint statements are only created for to-one relationships whose inverse is a to-many.

If neither of the above are true, this method creates a new EOSQLExpression, assigns its entity to aRelationship's entity, invokes prepareConstraintStatementForRelationship, and returns an array containing the expression.

If a subclass's database server's foreign key constraint semantics are different, the subclass should override this method or override the method prepareConstraintStatementForRelationship.

formatSQLString

public static String formatSQLString( String sqlString, String format)

Applies format (an EOAttribute object's "read" or "write" format) to sqlString (a value for the attribute). If format is null, this method returns sqlString unchanged.

See Also: readFormat (EOAttribute), writeFormat (EOAttribute)

formatStringValue

public static String formatStringValue(String string)

Formats string for use as a string constant in a SQL statement. EOSQLExpression's implementation encloses the string in single quotes, escaping any single quotes already present in string. Throws an exception if string is null.

formatValueForAttribute

public static String formatValueForAttribute( Object value, EOAttribute attribute)

Overridden by subclasses to return a string representation of value suitable for use in an SQL statement. EOSQLExpression's implementation returns value unchanged. A subclass should override this method to format value depending on attribute's externalType. For example, a subclass might format a date using a special database-specific syntax or standard form or truncate numbers to attribute's precision and scale.

insertStatementForRow

public static EOSQLExpression insertStatementForRow( NSDictionary row, EOEntity entity)

Creates and returns an SQL INSERT expression to insert row. Creates an instance of EOSQLExpression, initializes it with entity, and sends it prepareInsertExpressionWithRow. Throws an exception if entity is null.

The expression created with this method does not use table aliases because Enterprise Objects Framework assumes that all INSERT, UPDATE, and DELETE statements are single-table operations. To generate INSERT statements that do use table aliases, you must override prepareInsertExpressionWithRow to send a setUseAliases(true) message prior to invoking super's version.

isColumnTypeEquivalentToColumnType

public static boolean isColumnTypeEquivalentToColumnType( EOSQLExpression.EOColumnTypes columnTypeA, EOSQLExpression.EOColumnTypes columnTypeB, NSDictionary options)

Returns true if values in a column of columnTypeA can be copied into a column of columnTypeB without the use of a casting phrase, false otherwise. The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

phraseCastingColumnNamed

public static String phraseCastingColumnNamed( String columnName, EOSQLExpression.EOColumnTypes fromType, EOSQLExpression.EOColumnTypes castType NSDictionary options)

Returns an SQL string to cast the values in the column specified by columnName to a new type. This method is used when the adaptor doesn't support in-place column type coercion, and the table has to be recreated. To move data from the old table to the new table, sometimes a conversion statement is needed (for example, to convert strings in a VARCHAR column to numbers). The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

primaryKeyConstraintStatementsForEntityGroup

public static NSArray primaryKeyConstraintStatementsForEntityGroup(NSArray entityGroup)

Returns an array of EOSQLExpression objects that define the SQL necessary to create the primary key constraints for entityGroup, an array of EOEntity objects that have the same externalName. Returns an empty array if any of the primary key attributes in entityGroup don't have a columnName.

EOSQLExpression's implementation creates a statement of the following form:

ALTER TABLE TABLE_NAME ADD PRIMARY KEY (PRIMARY_KEY_COLUMN_NAMES)

Where TABLE_NAME is the externalName for the first entity in entityGroup and PRIMARY_KEY_COLUMN_NAMES is a comma-separated list of the columnNames of the first entity's primaryKeyAttributes.

If the subclass's database server's primary key constraint semantics are different, the subclass should override this method.

primaryKeyConstraintStatementsForEntityGroups

public static NSArray primaryKeyConstraintStatementsForEntityGroups(NSArray entityGroups)

Returns an array of EOSQLExpression objects that define the SQL necessary to create the primary key constraints for the Entities specified in entityGroups. An entity group is an array of Entity objects that have the same externalName, and entityGroups is an array of entity groups. EOSQLExpression's implementation invokes primaryKeySupportStatementsForEntityGroup for each entity group in entityGroups and returns an array of all the resulting EOSQLExpressions.

primaryKeySupportStatementsForEntityGroup

public static NSArray primaryKeySupportStatementsForEntityGroup(NSArray entityGroup)

Returns an array of EOSQLExpression objects that define the SQL necessary to create the primary key generation support for entityGroup, an array of EOEntity objects that have the same externalName. EOSQLExpression's implementation creates a statement of the following form:

create sequence SEQUENCE_NAME

Where SEQUENCE_NAME is the primaryKeyRootName for the first entity in entityGroup concatenated with "_SEQ" (EMP_ID_SEQ, for example).

If a subclass uses a different primary key generation mechanism or if the subclass's database server's drop semantics are different, the subclass should override this method.

See Also: dropPrimaryKeySupportStatementsForEntityGroup, primaryKeyForNewRowWithEntity (EOAdaptorChannel)

primaryKeySupportStatementsForEntityGroups

public static NSArray primaryKeySupportStatementsForEntityGroups(NSArray entityGroups)

Returns an array of EOSQLExpression objects that define the SQL necessary to create the primary key generation support for the Entities specified in entityGroups. An entity group is an array of Entity objects that have the same externalName, and entityGroups is an array of entity groups. EOSQLExpression's implementation invokes primaryKeySupportStatementsForEntityGroup for each entity group in entityGroups and returns an array of all the resulting EOSQLExpressions.

schemaCreationScriptForEntities

public static String schemaCreationScriptForEntities( NSArray entities, NSDictionary options)

Returns a script of SQL statements suitable to create the schema for the EOEntity objects in entities. The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" . EOSQLExpression's implementation invokes schemaCreationStatementsForEntities with entities and options and then uses appendExpression to generate the script from the EOSQLExpressions generated by schemaCreationStatementsForEntities.

schemaCreationStatementsForEntities

public static NSArray schemaCreationStatementsForEntities( NSArray entities, NSDictionary options)

Returns an array of EOSQLExpressions suitable to create the schema for the Entity objects in entities. The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

EOSQLExpression's implementation uses the following methods:

createTableStatementsForEntityGroups
dropTableStatementsForEntityGroups
primaryKeySupportStatementsForEntityGroups
dropPrimaryKeySupportStatementsForEntityGroups
primaryKeyConstraintStatementsForEntityGroups
foreignKeyConstraintStatementsForRelationship

to generate EOSQLExpressions for the support identified in options.

See Also: schemaCreationScriptForEntities

selectStatementForAttributes

public static EOSQLExpression selectStatementForAttributes( NSArray attributes, boolean flag, com.apple.yellow.eocontrol.EOFetchSpecification fetchSpecification, EOEntity entity)

Creates and returns an SQL SELECT expression. Creates an instance of EOSQLExpression, initializes it with entity, and sends it prepareSelectExpressionWithAttributes. The expression created with this method uses table aliases. Throws an exception if attributes is null or empty, fetchSpecification is null, or entity is null.

The expression created with this method uses table aliases. To generate SELECT statements that don't use them, you must override prepareSelectExpressionWithAttributes to send a setUseAliases(false) message prior to invoking super's version.

setUseBindVariables

public static void setUseBindVariables(boolean flag)

Sets according to flag whether all instances of EOSQLExpression subclasses use bind variables. By default, instances don't use bind variables; if the value for the global user default named EOAdaptorUseBindVariables is true, though, instances do use them. For more information on bind variables, see the discussion in the class description.

See Also: useBindVariables

setUseQuotedExternalNames

public static void setUseQuotedExternalNames(boolean flag)

Sets whether all instances of EOSQLExpression subclasses quote external names when they are referenced in SQL statements. By setting flag to true, you can access database tables with names such as "%return", "1st year", and "TABLE" that you couldn't otherwise access. By default, instances don't quote external names; if the value for the global user default named EOAdaptorQuotesExternalNames is true, though, instances do use quotes.

sqlPatternFromShellPattern

public static String sqlPatternFromShellPattern(String pattern)

Translates a "like" qualifier to an SQL "like" expression. Invoked from sqlStringForKeyValueQualifier when the qualifier argument is an EOKeyValueQualifier object whose selector is EOQualifier.QualifierOperatorLike. EOSQLExpression's implementation performs the following substitutions

Character in pattern	Substitution string
*	%
?	_
%	[%] (unless the percent character appears in square brackets)
_	[_] (unless the underscore character appears in square brackets)

sqlPatternFromShellPatternWithEscapeCharacter

public static String sqlPatternFromShellPatternWithEscapeCharacter( String pattern, char escapeCharacter)

Like sqlPatternFromShellPattern except the argument escapeCharacter allows you to specify a character for escaping the wild card characters "%" and "_".

statementsToConvertColumnType

public static NSArray statementsToConvertColumnType( String columnName, String tableName, EOSQLExpression.EOColumnTypes type, EOSQLExpression.EOColumnTypes newType, NSDictionary options)

Returns an array of EOSQLExpressions to convert in place the type of the specified column. The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToCopyTableNamed

public static NSArray statementsToCopyTableNamed( String tableName, NSArray entityGroup, NSDictionary changes, NSDictionary options)

Returns an array of EOSQLExpressions to copy the specified table into a new table, whose definition is provided by entityGroup-an array of EOEntity objects rooted to the table named tableName. This method is used when the adaptor doesn't support the in-place table modifications required to synchronize the database to a model.

The changes dictionary identifies the changes to make to the database schema; for more information, see "The Change Dictionary" . The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToDeleteColumnNamed

public static NSArray statementsToDeleteColumnNamed( String columnName, String tableName, NSDictionary options)

Returns an array of EOSQLExpressions to delete in place the specified column from the specified table. The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToDropForeignKeyConstraintsOnEntityGroup

public static NSArray statementsToDropForeignKeyConstraintsOnEntityGroup( NSArray entityGroup, NSDictionary changes, NSDictionary options)

Returns an array of EOSQLExpressions to drop foreign key constraints for the table corresponding to entityGroup-an array of EOEntity objects rooted to the same table. The changes dictionary identifies the changes to make to the database schema; for more information, see "The Change Dictionary" . The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToDropPrimaryKeyConstraintsOnEntityGroup

public static NSArray statementsToDropPrimaryKeyConstraintsOnEntityGroup( NSArray entityGroup, NSDictionary changes, NSDictionary options)

Returns an array of EOSQLExpressions to drop primary key constraints for the table corresponding to entityGroup-an array of EOEntity objects rooted to the same table. The changes dictionary identifies the changes to make to the database schema; for more information, see "The Change Dictionary" . The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToDropPrimaryKeySupportForEntityGroup

public static NSArray statementsToDropPrimaryKeySupportForEntityGroup( NSArray entityGroup, NSDictionary changes, NSDictionary options)

Returns an array of EOSQLExpressions to drop the primary key support mechanism for the table corresponding to entityGroup-an array of EOEntity objects rooted to the same table. The changes dictionary identifies the changes to make to the database schema; for more information, see "The Change Dictionary" . The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToImplementForeignKeyConstraintsOnEntityGroup

public static NSArray statementsToImplementForeignKeyConstraintsOnEntityGroup( NSArray entityGroup, NSDictionary changes, NSDictionary options)

Returns an array of EOSQLExpressions to implement foreign key constraints on the table corresponding to entityGroup-an array of EOEntity objects rooted to the same table. The changes dictionary identifies the changes to make to the database schema; for more information, see "The Change Dictionary" . The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToImplementPrimaryKeyConstraintsOnEntityGroup

public static NSArray statementsToImplementPrimaryKeyConstraintsOnEntityGroup( NSArray entityGroup, NSDictionary changes, NSDictionary options)

Returns an array of EOSQLExpressions to implement primary key constraints on the table corresponding to entityGroup-an array of EOEntity objects rooted to the same table. The changes dictionary identifies the changes to make to the database schema; for more information, see "The Change Dictionary" . The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToImplementPrimaryKeySupportForEntityGroup

public static NSArray statementsToImplementPrimaryKeySupportForEntityGroup( NSArray entityGroup, NSDictionary changes, NSDictionary options)

Returns an array of EOSQLExpressions to implement support mechanisms for primary key generation for the table corresponding to entityGroup-an array of EOEntity objects rooted to the same table. The changes dictionary identifies the changes to make to the database schema; for more information, see "The Change Dictionary" . The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToInsertColumnForAttribute

public static NSArray statementsToInsertColumnForAttribute( EOAttribute attribute, NSDictionary options)

Returns an array of EOSQLExpressions to insert in place a column for the specified attribute. The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToModifyColumnNullRule

public static NSArray statementsToModifyColumnNullRule( String columnName, String tableName, boolean allowsNull, NSDictionary options)

Returns an array of EOSQLExpressions to modify in place the specified column to either allow or not allow NULL values as specified by allowsNull. The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToRenameColumnNamed

public static NSArray statementsToRenameColumnNamed( String columnName, String tableName, String newName, NSDictionary options)

Returns an array of EOSQLExpressions to rename in place the specified column. The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToRenameTableNamed

public static NSArray statementsToRenameTableNamed( String tableName, String newName, NSDictionary options)

Returns an array of EOSQLExpressions to rename in place the specified table. The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToUpdateObjectStoreForEntityGroup

public static NSArray statementsToUpdateObjectStoreForEntityGroup( NSArray entityGroup, NSDictionary changes, NSDictionary options)

Returns an array of EOSQLExpressions to update the table that corresponds to entityGroup-an array of EOEntity objects rooted to the same table. Inserts and deletes columns, and updates modified columns. The changes dictionary identifies the changes to make to the database schema; for more information, see "The Change Dictionary" . The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

statementsToUpdateObjectStoreForModel

public static NSArray statementsToUpdateObjectStoreForModel( EOModel model, NSDictionary changes, NSDictionary options)

Returns an array of EOSQLExpressions to synchronize the database with model. Prepares the statements to insert and delete new and deleted tables before invoking statementsToUpdateObjectStoreForEntityGroup for each modified table. The changes dictionary identifies the changes to make to the database schema; for more information, see "The Change Dictionary" . The options dictionary describes the aspects of the schema for which to create SQL statements; for more information, see "The Options Dictionary" .

sqlStringForNumber

public static String sqlStringForNumber(Number aNumber)

Returns the SQL string for aNumber.

sqlStringForString

public static String sqlStringForString(String aString)

Returns the SQL string for aString.

supportsDirectColumnCoercion

public static boolean supportsDirectColumnCoercion()

Returns true if the adaptor can change the type of an existing column in place, false otherwise.

supportsDirectColumnDeletion

public static boolean supportsDirectColumnDeletion()

Returns true if the adaptor can delete columns, false otherwise.

supportsDirectColumnInsertion

public static boolean supportsDirectColumnInsertion()

Returns true if the adaptor can add columns to a table, false otherwise.

supportsDirectColumnNullRuleModification

public static boolean supportsDirectColumnNullRuleModification()

Returns true if the adaptor can modify the null rule of an existing column in place, false otherwise.

supportsDirectColumnRenaming

public static boolean supportsDirectColumnRenaming()

Returns true if the adaptor can rename table columns, false otherwise.

supportsSchemaSynchronization

public static boolean supportsSchemaSynchronization()

Returns true if the adaptor can update the database to reflect changes in a model, false otherwise.

updateStatementForRow

public static EOSQLExpression updateStatementForRow( NSDictionary row, com.apple.yellow.eocontrol.EOQualifier qualifier, EOEntity entity)

Creates and returns an SQL UPDATE expression to update the row identified by qualifier with the values in row. row should only contain entries for values that have actually changed. Creates an instance of EOSQLExpression, initializes it with entity, and sends it prepareUpdateExpressionWithRow.

The expression created with this method does not use table aliases because Enterprise Objects Framework assumes that all INSERT, UPDATE, and DELETE statements are single-table operations. As a result, all keys in qualifier should be simple key names; no key paths are allowed. To generate UPDATE statements that do use table aliases, you must override prepareUpdateExpressionWithRow to send a setUseAliases(true) message prior to invoking super's version.

See Also: setUseAliases

useBindVariables

public static boolean useBindVariables()

Returns true if instances use bind variables, false otherwise. For more information on bind variables, see the discussion in the class description.

See Also: setUseBindVariables

useQuotedExternalNames

public static boolean useQuotedExternalNames()

Returns true if instances use quoted external names, false otherwise.

Instance Methods

addBindVariableDictionary

public void addBindVariableDictionary(NSMutableDictionary binding)

Adds binding to the receiver's array of bind variable dictionaries. binding is generally created using the method bindVariableDictionaryForAttribute and is added to the receiver's bind variable dictionaries in sqlStringForValue when the receiver uses a bind variable for the specified attribute. See the method description for bindVariableDictionaryForAttribute for a description of the contents of a bind variable dictionary, and for more information on bind variables, see the discussion in the class description.

See Also: bindVariableDictionaries

addCreateClauseForAttribute

public void addCreateClauseForAttribute(EOAttribute attribute)

Adds the SQL string for creating attribute to a comma-separated list of attribute creation clauses. The list is constructed for use in a CREATE TABLE statement produced by createTableStatementsForEntityGroup. Use the method listString to access creation clauses.

EOSQLExpression's implementation creates clauses in the following form:

COLUMN_NAME COLUMN_TYPE ALLOWS_NULL_CLAUSE

Where

COLUMN_TYPE is the string returned from columnTypeStringForAttribute for anAttribute.
ALLOWS_NULL_CLAUSE is the string returned from allowsNullClauseForConstraint with true if anAttribute allowsNull or with false if anAttribute doesn't.

addInsertListAttribute

public void addInsertListAttribute( EOAttribute attribute, String value)

Adds the SQL string for attribute to a comma-separated list of attributes and value to a comma-separated list of values. Both lists are constructed for use in an INSERT statement. Use the methods listString and valueList to access the attributes and value lists.

Invokes appendItemToListString to add an SQL string for attribute to the receiver's listString, and again to add a formatted SQL string for value to the receiver's valueList.

addJoinClause

public void addJoinClause( String leftName, String rightName, int semantic)

Creates a new join clause by invoking assembleJoinClause and adds it to the receiver's join clause string. Separates join conditions already in the join clause string with the word "and". Invoked from joinExpression.

See Also: joinClauseString

addOrderByAttributeOrdering

public void addOrderByAttributeOrdering(com.apple.yellow.eocontrol.EOSortOrdering sortOrdering)

Adds an attribute-direction pair ("LAST_NAME asc", for example) to the receiver's ORDER BY string. If sortOrdering's selector is EOSortOrdering.CompareCaseInsensitiveAscending or EOSortOrdering.CompareCaseInsensitiveAscending, the string generated has the format "upper(attribute) direction". Use the method orderByString to access the ORDER BY string. addOrderByAttributeOrdering invokes appendItemToListString to add the attribute-direction pair.

See Also: sqlStringForAttributeNamed

addSelectListAttribute

public void addSelectListAttribute(EOAttribute attribute)

Adds an SQL string for attribute to a comma-separated list of attribute names for use in a SELECT statement. The SQL string for attribute is formatted with attribute's "read" format. Use listString to access the list. addSelectListAttribute invokes appendItemToListString to add the attribute name.

See Also: sqlStringForAttribute, formatSQLString, readFormat (EOAttribute)

addUpdateListAttribute

public void addUpdateListAttribute( EOAttribute attribute, String value)

Adds an attribute-value assignment ("LAST_NAME = ‘Thomas'", for example) to a comma-separated list for use in an UPDATE statement. Formats value with attribute's "write" format. Use listString to access the list. addUpdateListAttribute invokes appendItemToListString to add the attribute-value assignment.

See Also: formatSQLString

aliasesByRelationshipPath

public NSMutableDictionary aliasesByRelationshipPath()

Returns a dictionary of table aliases. The keys of the dictionary are relationship paths-"department" and "department.location", for example. The values are the table aliases for the corresponding table-"t1" and "t2", for example. The aliasesByRelationshipPath dictionary always has at least one entry: an entry for the EOSQLExpression's entity. The key of this entry is the empty string ("") and the value is "t0". The dictionary returned from this method is built up over time with successive calls to sqlStringForAttributePath.

See Also: tableListWithRootEntity

allowsNullClauseForConstraint

public String allowsNullClauseForConstraint(boolean flag)

Returns according to flag an adaptor specific string for use in a CREATE TABLE statement. The returned string indicates whether a column allows null values. EOSQLExpression's implementation returns the empty string if flag is true, "NOT NULL" otherwise. A subclass should override this if its database server's semantics are different. For example, the SybaseSLQExpression returns "null" if flag is true, the empty string otherwise.

See Also: addCreateClauseForAttribute

appendItemToListString

public void appendItemToListString( String itemString, String listString)

Adds itemString to a comma-separated list. If listString already has entries, this method appends a comma followed by itemString. Invoked from addSelectListAttribute, addInsertListAttribute, addUpdateListAttribute, and addOrderByAttributeOrdering

assembleDeleteStatementWithQualifier

public String assembleDeleteStatementWithQualifier( com.apple.yellow.eocontrol.EOQualifier qualifier, String tableList, String whereClause)

Invoked from prepareDeleteExpressionForQualifier to return an SQL DELETE statement of the form:

DELETE FROM tableList
SQL_WHERE whereClause

qualifier is the argument to prepareDeleteExpressionForQualifier from which whereClause was derived. It is provided for subclasses that need to generate the WHERE clause in a particular way.

assembleInsertStatementWithRow

public String assembleInsertStatementWithRow( NSDictionary row, String tableList, String columnList, String valueList)

Invoked from prepareInsertExpressionWithRow to return an SQL INSERT statement of the form:

INSERT INTO tableList (columnList)
VALUES valueList

or, if columnList is null:

INSERT INTO tableList
VALUES valueList

row is the argument to prepareInsertExpressionWithRow from which columnList and valueList were derived. It is provided for subclasses that need to generate the list of columns and values in a particular way.

assembleJoinClause

public String assembleJoinClause( String leftName, String rightName, int semantic)

Returns a join clause of the form:

leftName operator rightName

Where operator is "=" for an inner join, "*=" for a left-outer join, and "=*" for a right-outer join. Invoked from addJoinClause.

assembleSelectStatementWithAttributes

public String assembleSelectStatementWithAttributes( NSArray attributes, boolean lock, com.apple.yellow.eocontrol.EOQualifier qualifier, NSArray fetchOrder, String selectString, String columnList, String tableList, String whereClause, String joinClause, String orderByClause, String lockClause)

Invoked from prepareSelectExpressionWithAttributes to return an SQL SELECT statement of the form:

SELECT columnList
FROM tableList lockClause 
WHERE whereClause AND joinClause 
ORDER BY orderByClause

If lockClause is null, it is omitted from the statement. Similarly, if orderByClause is null, the "ORDER BY orderByClause" is omitted. If either whereClause or joinClause is null, the "AND" and null-valued argument are omitted. If both are null, the entire WHERE clause is omitted.

attributes, lock, qualifier, and fetchOrder are the arguments to prepareSelectExpressionWithAttributes from which the other assembleSelect... arguments were derived. They are provided for subclasses that need to generate the clauses of the SELECT statement in a particular way.

assembleUpdateStatementWithRow

public String assembleUpdateStatementWithRow( NSDictionary row, com.apple.yellow.eocontrol.EOQualifier qualifier, String tableList, String updateList, String whereClause)

Invoked from prepareUpdateExpressionWithRow to return an SQL UPDATE statement of the form:

UPDATE tableList
SET updateList
WHERE whereClause

row and qualifier are the arguments to prepareUpdateExpressionWithRow from which updateList and whereClause were derived. They are provided for subclasses that need to generate the clauses of the UPDATE statement in a particular way.

bindVariableDictionaries

public NSArray bindVariableDictionaries()

Returns the receiver's bind variable dictionaries. For more information on bind variables, see the discussion in the class description.

See Also: addBindVariableDictionary

bindVariableDictionaryForAttribute

public NSMutableDictionary bindVariableDictionaryForAttribute( EOAttribute attribute, Object value)

Implemented by subclasses to create and return the bind variable dictionary for attribute and value. The dictionary returned from this method must contain the following key-value pairs:

Key	Corresponding Value
`BindVariableNameKey`	Name of the bind variable for attribute
`BindVariablePlaceHolderKey`	Placeholder string used in the SQL statement
`BindVariableAttributeKey`	attribute
`BindVariableValueKey`	value

An adaptor subclass may define additional entries as required by its RDBMS.

Invoked from sqlStringForValue when the message mustUseBindVariableForAttribute(attribute) returns true or when the receiver's class uses bind variables and the message shouldUseBindVariableForAttribute(attribute) returns true. For more information on bind variables, see the discussion in the class description.

A subclass that uses bind variables should implement this method without invoking EOSQLExpression's implementation. The subclass implementation must return a dictionary with entries for the keys listed above and may add additional keys.

columnTypeStringForAttribute

public String columnTypeStringForAttribute(EOAttribute anAttribute)

Returns an adaptor specific type string for anAttribute that's suitable for use in a CREATE TABLE statement. EOSQLExpression's implementation creates a string based on anAttribute's externalType, precision, and width as follows:

If Condition	Generated String
precision is non-zero	externalType(precision, scale)
precision is zero and width is non-zero	externalType(scale)
precision and width are zero	externalType

A subclass should override the default implementation if its database server requires column types in a different format.

See Also: addCreateClauseForAttribute

entity

public EOEntity entity()

Returns the receiver's entity.

See Also: EOSQLExpression constructor

externalNameQuoteCharacter

public String externalNameQuoteCharacter()

Returns the string ‘\"' (an escaped quote character) if the receiver uses quoted external names, or the empty string ("") otherwise.

joinClauseString

public String joinClauseString()

Returns the part of the receiver's WHERE clause that specifies join conditions. Together, the joinExpression and the whereClauseString make up a statement's WHERE clause. If the receiver's statement doesn't contain join conditions, this method returns an empty string.

An EOSQLExpression's joinClauseString is generally set by invoking joinExpression.

See Also: addJoinClause

joinExpression

public void joinExpression()

Builds up the joinClauseString for use in a SELECT statement. For each relationship path in the aliasesByRelationshipPath dictionary, this method invokes addJoinClause for each of the relationship's EOJoin objects.

If the aliasesByRelationshipPath dictionary only has one entry (the entry for the EOSQLExpression's entity), the joinClauseString is empty.

You must invoke this method after invoking addSelectListAttribute for each attribute to be selected and after sending sqlStringForSQLExpression(this) to the qualifier for the SELECT statement. (These methods build up the aliasesByRelationshipPath dictionary by invoking sqlStringForAttributePath.)

See Also: whereClauseString

listString

public String listString()

Returns a comma-separated list of attributes or "attribute = value" assignments. listString is built up with successive invocations of addInsertListAttribute, addSelectListAttribute, or addUpdateListAttribute for INSERT statements, SELECT statements, and UPDATE statements, respectively. The contents of listString vary according to the type of statement the receiver is building:

Type of Statement	Sample listString Contents
INSERT	FIRST_NAME, LAST_NAME, EMPLOYEE_ID
UPDATE	FIRST_NAME = "Timothy", LAST_NAME = "Richardson"
SELECT	t0.FIRST_NAME, t0.LAST_NAME, t1.DEPARTMENT_NAME

lockClause

public String lockClause()

Overridden by subclasses to return the SQL string used in a SELECT statement to lock selected rows. A concrete subclass of EOSQLExpression must override this method to return the string used by its adaptor's RDBMS.

mustUseBindVariableForAttribute

public boolean mustUseBindVariableForAttribute(EOAttribute attribute)

Returns true if the receiver must use bind variables for attribute, false otherwise. EOSQLExpression's implementation returns false. An SQL expression subclass that uses bind variables should override this method to return true if the underlying RDBMS requires that bind variables be used for attributes with attribute's external type.

orderByString

public String orderByString()

Returns the comma-separated list of "attribute direction" pairs ("LAST_NAME asc, FIRST_NAME asc", for example) for use in a SELECT statement.

See Also: addOrderByAttributeOrdering

prepareConstraintStatementForRelationship

public void prepareConstraintStatementForRelationship( EORelationship relationship, NSArray sourceColumns, NSArray destinationColumns)

Sets the receiver's statement to an adaptor specific constraint for relationship. EOSQLExpression's implementation generates statements of the form:

ALTER TABLE TABLE_NAME ADD CONSTRAINT CONSTRAINT_NAME
    FOREIGN KEY (SOURCE_KEY_LIST)
    REFERENCES DESTINATION_TABLE_NAME (DESTINATION_KEY_LIST)

Where

TABLE_NAME is the external name of the receiver's entity.
CONSTRAINT_NAME is the external name of the receiver's entity, relationship's name, and the string "FK", concatenated with underbars between them (EMPLOYEE_MANAGER_FK, for example),
SOURCE_KEY_LIST is a comma-separated list of the source columns in sourceColumns.
DESTINATION_TABLE_NAME is the external name of relationship's destination entity.
DESTINATION_KEY_LIST is a comma-separated list of the destination columns in destinationColumns

prepareDeleteExpressionForQualifier

public void prepareDeleteExpressionForQualifier( com.apple.yellow.eocontrol.EOQualifier qualifier)

Generates a DELETE statement by performing the following steps:

Sends an sqlStringForSQLExpression(this) message to qualifier to generate the receiver's whereClauseString.
Invokes tableListWithRootEntity to get the table name for the FROM clause.
Invokes assembleDeleteStatementWithQualifier.

See Also: deleteStatementWithQualifier

prepareInsertExpressionWithRow

public void prepareInsertExpressionWithRow(NSDictionary row)

Generates an INSERT statement by performing the following steps:

Invokes addInsertListAttribute for each entry in row to prepare the comma-separated list of attributes and the corresponding list of values.
Invokes tableListWithRootEntity to get the table name.
Invokes assembleInsertStatementWithRow.

See Also: insertStatementForRow

prepareSelectExpressionWithAttributes

public void prepareSelectExpressionWithAttributes( NSArray attributes, boolean flag, com.apple.yellow.eocontrol.EOFetchSpecification fetchSpecification)

Generates a SELECT statement by performing the following steps:

Invokes addSelectListAttribute for each entry in attributes to prepare the comma-separated list of attributes.
Sends an sqlStringForSQLExpression(this) message to fetchSpecification's qualifier to generate the receiver's whereClauseString.
Invokes addOrderByAttributeOrdering for each EOAttributeOrdering object in fetchSpecification. First conjoins the qualifier in fetchSpecification with the restricting qualifier, if any, of the receiver's entity.
Invokes joinExpression to generate the receiver's joinClauseString.
Invokes tableListWithRootEntity to get the comma-separated list of tables for the FROM clause.
If flag is true, invokes lockClause to get the SQL string to lock selected rows.
Invokes assembleSelectStatementWithAttributes.

See Also: selectStatementForAttributes

prepareUpdateExpressionWithRow

public void prepareUpdateExpressionWithRow( NSDictionary row, com.apple.yellow.eocontrol.EOQualifier qualifier)

Generates an UPDATE statement by performing the following steps:

Invokes addUpdateListAttribute for each entry in row to prepare the comma-separated list of "attribute = value" assignments.
Sends an sqlStringForSQLExpression(this) message to qualifier to generate the receiver's whereClauseString.
Invokes tableListWithRootEntity to get the table name for the FROM clause.
Invokes assembleUpdateStatementWithRow.

See Also: updateStatementForRow

setStatement

public void setStatement(String string)

Sets the receiver's SQL statement to string, which should be a valid expression in the target query language. Use this method-instead of a prepare... method-to directly assign an SQL string to an EOSQLExpression object. This method does not perform substitutions or formatting of any kind.

See Also: expressionForString, statement

setUseAliases

public void setUseAliases(boolean flag)

Tells the receiver whether or not to use table aliases.

See Also: useAliases

shouldUseBindVariableForAttribute

public boolean shouldUseBindVariableForAttribute(EOAttribute attribute)

Returns true if the receiver can provide a bind variable dictionary for attribute, false otherwise. Bind variables aren't used for values associated with this attribute when the static method useBindVariables returns false. EOSQLExpression's implementation returns false. An SQL expression subclass should override this method to return true if the receiver should use bind variables for attributes with attribute's external type. It should also return true for any attribute for which the receiver must use bind variables.

See Also: mustUseBindVariableForAttribute

sqlStringForAttribute

public String sqlStringForAttribute(EOAttribute attribute)

Returns the SQL string for attribute, complete with a table alias if the receiver uses table aliases. Invoked from sqlStringForAttributeNamed when the attribute name is not a path.

See Also: sqlStringForAttributePath

sqlStringForAttributeNamed

public String sqlStringForAttributeNamed(String name)

Returns the SQL string for the attribute named name, complete with a table alias if the receiver uses table aliases. Generates the return value using sqlStringForAttributePath if name is an attribute path ("department.name", for example); otherwise, uses sqlStringForAttribute.

sqlStringForAttributePath

public String sqlStringForAttributePath(NSArray path)

Returns the SQL string for path, complete with a table alias if the receiver uses table aliases. Invoked from sqlStringForAttributeNamed when the specified attribute name is a path ("department.location.officeNumber", for example). path is an array of any number of EORelationship objects followed by an EOAttribute object. The EORelationship and EOAttribute objects each correspond to a component in path. For example, if the attribute name argument to sqlStringForAttributeNamed is "department.location.officeNumber", path is an array containing the following objects in the order listed:

The EORelationship object in the receiver's entity named "department". (Assume the relationship's destination entity is named "Department".)
The EORelationship object in the Department entity named "location". (Assume the relationship's destination entity is named "Location".)
The EOAttribute object in the Location entity named "officeNumber".

Assuming that the receiver uses aliases and the alias for the Location table is t2, the SQL string for this sample attribute path is "t2.officeNumber".

If the receiver uses table aliases, this method has the side effect of adding a "relationship path"-"alias name" entry to the aliasesByRelationshipPath dictionary.

sqlStringForCaseInsensitiveLike

public String sqlStringForCaseInsensitiveLike( String valueString, String keyString)

Overridden by subclasses to return a case insensitive comparison of valueString and keyString. For example, a subclass implementation might return the string "UPPER(keyString) LIKE UPPER(valueString)".

sqlStringForConjoinedQualifiers

public String sqlStringForConjoinedQualifiers(NSArray qualifiers)

Creates and returns an SQL string that is the result of interposing the word "AND" between the SQL strings for the qualifiers in qualifiers. Generates an SQL string for each qualifier by sending sqlStringForSQLExpression: messages to the qualifiers with this as the argument. If the SQL string for a qualifier contains only white space, it isn't included in the return value. The return value is enclosed in parentheses if the SQL strings for two or more qualifiers were ANDed together.

sqlStringForDisjoinedQualifiers

public String sqlStringForDisjoinedQualifiers(NSArray qualifiers)

Creates and returns an SQL string that is the result of interposing the word "OR" between the SQL strings for the qualifiers in qualifiers. Generates an SQL string for each qualifier by sending sqlStringForSQLExpression: messages to the qualifiers with this as the argument. If the SQL string for a qualifier contains only white space, it isn't included in the return value. The return value is enclosed in parentheses if the SQL strings for two or more qualifiers were ORed together.

sqlStringForKeyComparisonQualifier

public String sqlStringForKeyComparisonQualifier( com.apple.yellow.eocontrol.EOKeyComparisonQualifier qualifier)

Creates and returns an SQL string that is the result of interposing an operator between the SQL strings for the right and left keys in qualifier. Determines the SQL operator by invoking sqlStringForSelector with qualifier's selector and null for the value. Generates SQL strings for qualifier's keys by invoking sqlStringForAttributeNamed to get SQL strings. This method also formats the strings for the right and left keys using formatSQLString with the corresponding attributes' "read" formats.

sqlStringForKeyValueQualifier

public String sqlStringForKeyValueQualifier( com.apple.yellow.eocontrol.EOKeyValueQualifier qualifier)

Creates and returns an SQL string that is the result of interposing an operator between the SQL strings for qualifier's key and value. Determines the SQL operator by invoking sqlStringForSelector with qualifier's selector and value. Generates an SQL string for qualifier's key by invoking sqlStringForAttributeNamed to get an SQL string and formatSQLString with the corresponding attribute's "read" format. Similarly, generates an SQL string for qualifier's value by invoking sqlStringForValue to get an SQL string and formatValueForAttribute to format it. (First invokes sqlPatternFromShellPattern for the value if qualifier's selector is EOQualifier.QualifierOperatorLike.)

sqlStringForNegatedQualifier

public String sqlStringForNegatedQualifier(com.apple.yellow.eocontrol.EOQualifier qualifier)

Creates and returns an SQL string that is the result of surrounding the SQL string for qualifier in parentheses and appending it to the word "not". For example, if the string for qualifier is "FIRST_NAME = ‘John'", sqlStringForNegatedQualifier returns the string "not (FIRST_NAME = ‘John')".

Generates an SQL string for qualifier by sending an sqlStringForSQLExpression: message to qualifier with this as the argument. If the SQL string for qualifier contains only white space, this method returns null.

sqlStringForQualifier

public String sqlStringForQualifier(com.apple.yellow.eocontrol.EOQualifier aQualifier)

Returns a SQL statement for aQualifier suitable for inclusion in a WHERE clause. Invoked from an EOSQLExpression while it's preparing a SELECT, UPDATE, or DELETE statement.

See Also: whereClauseString

sqlStringForSchemaObjectName

public String sqlStringForSchemaObjectName(String name)

Returns name enclosed in the external name quote character if the receiver uses quoted external names, otherwise simply returns name unaltered.

sqlStringForSelector

public String sqlStringForSelector( NSSelector selector, Object value)

Returns an SQL operator for selector and value. The possible values for selector are defined as constants (in EOControl). The following table summarizes EOSQLExpression's default mapping:

Selector (Constant)	SQL Operator
`EOQualifier.QualifierOperatorIsEqual`	"is" if value is an EONullValue, "=" otherwise
`EOQualifier.QualifierOperatorNotEqual`	"is not" if value is an EONullValue, "<>" otherwise
`EOQualifier.QualifierOperatorLessThan`	"<"
`EOQualifier.QualifierOperatorGreaterThan`	">"
`EOQualifier.QualifierOperatorLessThanOrEqualTo`	"<="
`EOQualifier.QualifierOperatorGreaterThanOrEqualTo`	">="
`EOQualifier.QualifierOperatorLike`	"like"

Throws an exception if selector is an unknown operator.

sqlStringForValue

public String sqlStringForValue( Object value, String name)

Returns a string for value appropriate for use in an SQL statement. If the receiver uses a bind variable for the attribute named name, then sqlStringForValue gets the bind variable dictionary for the attribute, adds it to the receiver's array of bind variables dictionaries, and returns the value for the binding's BindVariablePlaceHolderKey. Otherwise, this method invokes formatValueForAttribute and returns the formatted string for value.

statement

public String statement()

Returns the complete SQL statement for the receiver. An SQL statement can be assigned to an EOSQLExpression object directly using the static method expressionForString or using the instance method setStatement. Generally, however, an EOSQLExpression's statement is built up using one of the following methods:

prepareSelectExpressionWithAttributes
prepareInsertExpressionWithRow
prepareUpdateExpressionWithRow
prepareDeleteExpressionForQualifier

tableListWithRootEntity

public String tableListWithRootEntity(EOEntity entity)

Returns the comma-separated list of tables for use in a SELECT, UPDATE, or DELETE statement's FROM clause. If the receiver doesn't use table aliases, the table list consists only of the table name for entity-"EMPLOYEE", for example. If the receiver does use table aliases (only in SELECT statements by default), the table list is a comma separated list of table names and their aliases, for example:

EMPLOYEE t0, DEPARTMENT t1

tableListWithRootEntity creates a string containing the table name for entity and a corresponding table alias ("EMPLOYEE t0", for example). For each entry in aliasesByRelationshipPath, this method appends a new table name and table alias.

See Also: useAliases, aliasesByRelationshipPath

useAliases

public boolean useAliases()

Returns true if the receiver generates statements with table aliases, false otherwise. For example, the following SELECT statement uses table aliases:

SELECT t0.FIRST_NAME, t0.LAST_NAME, t1.NAME
FROM EMPLOYEE t0, DEPARTMENT t1
WHERE t0.DEPARTMENT_ID = t1.DEPARTMENT_ID

The EMPLOYEE table has the alias t0, and the DEPARTMENT table has the alias t1.

By default, EOSQLExpression uses table aliases only in SELECT statements. Enterprise Objects Framework assumes that INSERT, UPDATE, and DELETE statements are single-table operations. For more information, see the discussion in the class description.

valueList

public String valueList()

Returns the comma-separated list of values used in an INSERT statement. For example, the value list for the following INSERT statement:

INSERT EMPLOYEE (FIRST_NAME, LAST_NAME, EMPLOYEE_ID, DEPARTMENT_ID, SALARY)
VALUES ('Shaun', 'Hayes', 1319, 23, 4600)

is "‘Shaun', ‘Hayes', 1319, 23, 4600". An EOSQLExpression's valueList is generated a value at a time with addInsertListAttribute messages.

whereClauseString

public String whereClauseString()

Returns the part of the receiver's WHERE clause that qualifies rows. The whereClauseString does not specify join conditions; the joinClauseString does that. Together, the whereClauseString and the joinClauseString make up a statement's where clause. For example, a qualifier for an Employee entity specifies that a statement only affects employees who belong to the Finance department and whose monthly salary is greater than $4500. Assume the corresponding where clause looks like this:

WHERE EMPLOYEE.SALARY > 4500 AND DEPARTMENT.NAME = ‘Finance'
    AND EMPLOYEE.DEPARTMENT_ID = DEPARTMENT.DEPARTMENT_ID

EOSQLExpression generates both a whereClauseString and a joinClauseString for this qualifier. The whereClauseString qualifies the rows and looks like this:

EMPLOYEE.SALARY > 4500 AND DEPARTMENT.NAME = ‘Finance'

The joinClauseString specifies the join conditions between the EMPLOYEE table and the DEPARTMENT table and looks like this:

EMPLOYEE.DEPARTMENT_ID = DEPARTMENT.DEPARTMENT_ID

An EOSQLExpression's whereClauseString is generally set by sending a sqlStringForSQLExpression: message to an EOQualifier object.

See Also: sqlStringForSQLExpression: (EOQualifierSQLGeneration protocol)