Trait SqlserverDialectTrait
Contains functions that encapsulates the SQL dialect used by SQLServer, including query translators and schema introspection.
Property Summary
-
$_endQuote protected
stringString used to end a database identifier quoting to make it safe
-
$_startQuote protected
stringString used to start a database identifier quoting to make it safe
Method Summary
-
_deleteQueryTranslator() protected
Apply translation steps to delete queries.
-
_expressionTranslators() protected
Returns a dictionary of expressions to be transformed when compiling a Query to SQL. Array keys are method names to be called in this class
-
_insertQueryTranslator() protected
Apply translation steps to insert queries.
-
_pagingSubquery() protected
Generate a paging subquery for older versions of SQLserver.
-
_removeAliasesFromConditions() protected
Removes aliases from the
WHEREclause of a query. -
_selectQueryTranslator() protected
Modify the limit/offset to TSQL
-
_transformDistinct() protected
Returns the passed query after rewriting the DISTINCT clause, so that drivers that do not support the "ON" part can provide the actual way it should be done
-
_transformFunctionExpression() protected
Receives a FunctionExpression and changes it so that it conforms to this SQL dialect.
-
_transformTupleComparison() protected
Receives a TupleExpression and changes it so that it conforms to this SQL dialect.
-
_updateQueryTranslator() protected
Apply translation steps to update queries.
-
_version() public
Get the version of SQLserver we are connected to.
-
disableForeignKeySQL() public
{@inheritDoc}
-
enableForeignKeySQL() public
{@inheritDoc}
-
newCompiler() public
{@inheritDoc}
-
queryTranslator() public
Returns a callable function that will be used to transform a passed Query object. This function, in turn, will return an instance of a Query object that has been transformed to accommodate any specificities of the SQL dialect in use.
-
quoteIdentifier() public
Quotes a database identifier (a column name, table name, etc..) to be used safely in queries without the risk of using reserved words
-
releaseSavePointSQL() public
Returns a SQL snippet for releasing a previously created save point
-
rollbackSavePointSQL() public
Returns a SQL snippet for rollbacking a previously created save point
-
savePointSQL() public
Returns a SQL snippet for creating a new transaction savepoint
-
schemaDialect() public
Get the schema dialect.
Method Detail
_deleteQueryTranslator() ¶ protected
_deleteQueryTranslator(Cake\Database\Query $query): Cake\Database\QueryApply translation steps to delete queries.
Chops out aliases on delete query conditions as most database dialects do not support aliases in delete queries. This also removes aliases in table names as they frequently don't work either.
We are intentionally not supporting deletes with joins as they have even poorer support.
Parameters
-
Cake\Database\Query$query The query to translate
Returns
Cake\Database\Query_expressionTranslators() ¶ protected
_expressionTranslators(): arrayReturns a dictionary of expressions to be transformed when compiling a Query to SQL. Array keys are method names to be called in this class
Returns
array_insertQueryTranslator() ¶ protected
_insertQueryTranslator(Cake\Database\Query $query): Cake\Database\QueryApply translation steps to insert queries.
Parameters
-
Cake\Database\Query$query The query to translate
Returns
Cake\Database\Query_pagingSubquery() ¶ protected
_pagingSubquery(Cake\Database\Query $original, int $limit, int $offset): Cake\Database\QueryGenerate a paging subquery for older versions of SQLserver.
Prior to SQLServer 2012 there was no equivalent to LIMIT OFFSET, so a subquery must be used.
Parameters
-
Cake\Database\Query$original The query to wrap in a subquery.
-
int$limit The number of rows to fetch.
-
int$offset The number of rows to offset.
Returns
Cake\Database\Query_removeAliasesFromConditions() ¶ protected
_removeAliasesFromConditions(Cake\Database\Query $query): Cake\Database\QueryRemoves aliases from the WHERE clause of a query.
Parameters
-
Cake\Database\Query$query The query to process.
Returns
Cake\Database\QueryThrows
RuntimeExceptionIn case the processed query contains any joins, as removing aliases from the conditions can break references to the joined tables.
_selectQueryTranslator() ¶ protected
_selectQueryTranslator(Cake\Database\Query $query): Cake\Database\QueryModify the limit/offset to TSQL
Parameters
-
Cake\Database\Query$query The query to translate
Returns
Cake\Database\Query_transformDistinct() ¶ protected
_transformDistinct(Cake\Database\Query $original): Cake\Database\QueryReturns the passed query after rewriting the DISTINCT clause, so that drivers that do not support the "ON" part can provide the actual way it should be done
Parameters
-
Cake\Database\Query$original The query to be transformed
Returns
Cake\Database\Query_transformFunctionExpression() ¶ protected
_transformFunctionExpression(Cake\Database\Expression\FunctionExpression $expression): voidReceives a FunctionExpression and changes it so that it conforms to this SQL dialect.
Parameters
-
Cake\Database\Expression\FunctionExpression$expression The function expression to convert to TSQL.
Returns
void_transformTupleComparison() ¶ protected
_transformTupleComparison(Cake\Database\Expression\TupleComparison $expression, Cake\Database\Query $query): voidReceives a TupleExpression and changes it so that it conforms to this SQL dialect.
It transforms expressions looking like '(a, b) IN ((c, d), (e, f))' into an equivalent expression of the form '((a = c) AND (b = d)) OR ((a = e) AND (b = f))'.
It can also transform transform expressions where the right hand side is a query selecting the same amount of columns as the elements in the left hand side of the expression:
(a, b) IN (SELECT c, d FROM a_table) is transformed into
1 = (SELECT 1 FROM a_table WHERE (a = c) AND (b = d))
Parameters
-
Cake\Database\Expression\TupleComparison$expression The expression to transform
-
Cake\Database\Query$query The query to update.
Returns
void_updateQueryTranslator() ¶ protected
_updateQueryTranslator(Cake\Database\Query $query): Cake\Database\QueryApply translation steps to update queries.
Chops out aliases on update query conditions as not all database dialects do support aliases in update queries.
Just like for delete queries, joins are currently not supported for update queries.
Parameters
-
Cake\Database\Query$query The query to translate
Returns
Cake\Database\QuerynewCompiler() ¶ public
newCompiler(): Cake\Database\SqlserverCompiler{@inheritDoc}
Returns
Cake\Database\SqlserverCompilerqueryTranslator() ¶ public
queryTranslator(string $type): callableReturns a callable function that will be used to transform a passed Query object. This function, in turn, will return an instance of a Query object that has been transformed to accommodate any specificities of the SQL dialect in use.
Parameters
-
string$type the type of query to be transformed (select, insert, update, delete)
Returns
callablequoteIdentifier() ¶ public
quoteIdentifier(string $identifier): stringQuotes a database identifier (a column name, table name, etc..) to be used safely in queries without the risk of using reserved words
Parameters
-
string$identifier The identifier to quote.
Returns
stringreleaseSavePointSQL() ¶ public
releaseSavePointSQL(string $name): stringReturns a SQL snippet for releasing a previously created save point
Parameters
-
string$name save point name
Returns
stringrollbackSavePointSQL() ¶ public
rollbackSavePointSQL(string $name): stringReturns a SQL snippet for rollbacking a previously created save point
Parameters
-
string$name save point name
Returns
stringsavePointSQL() ¶ public
savePointSQL(string $name): stringReturns a SQL snippet for creating a new transaction savepoint
Parameters
-
string$name save point name
Returns
stringschemaDialect() ¶ public
schemaDialect(): Cake\Database\Schema\SqlserverSchemaGet the schema dialect.
Used by Cake\Schema package to reflect schema and generate schema.
Returns
Cake\Database\Schema\SqlserverSchema