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SQLEngine::Driver::TraUserNContributed PeSQLEngine::Driver::Trait::NoUnions(3)

NAME
       DBIx::SQLEngine::Driver::Trait::NoUnions	- For databases	without	select
       unions

SYNOPSIS
	 # Classes can import this behavior if they don't have native unions
	 use DBIx::SQLEngine::Driver::Trait::NoUnions ':all';

	 # Implements a	workaround for unavailable sql_union capability
	 $rows = $sqldb->fetch_select_rows( union => [
	   { table => 'foo', columns =>	'*' },
	   { table => 'bar', columns =>	'*' },
	 ] );

DESCRIPTION
       This package supports SQL database servers which	do natively provide a
       SQL select with unions. Instead,	queries	with unions are	executed
       separately and their results combined.

   About Driver	Traits
       You do not need to use this package directly; it	is used	internally by
       those driver subclasses which need it.

       For more	information about Driver Traits, see "About Driver Traits" in
       DBIx::SQLEngine::Driver.

REFERENCE
       The following methods are provided:

   Database Capability Information
       dbms_union_unsupported()
	     $sqldb->dbms_union_unsupported() :	1

	   Capability Limitation: This driver does not support native select
	   unions.

   Select to Retrieve Data
       fetch_select()
	     $sqldb->fetch_select( %sql_clauses	) : $row_hashes
	     $sqldb->fetch_select( %sql_clauses	) : ($row_hashes,$column_hashes)

	   Unless passed a "union" argument pair, simply calls the superclass
	   method.  Runs each of the provided queries separately and
	   concatenates	their results.	Munges the keys	used to	turn rows into
	   hashes, so that all results use the column names produced by	the
	   first of the	queries.

       fetch_select_rows()
	     $sqldb->fetch_select_rows(	%sql_clauses ) : $row_arrays
	     $sqldb->fetch_select_rows(	%sql_clauses ) : ($row_arrays,$column_hashes)

	   Unless passed a "union" argument pair, simply calls the superclass
	   method.  Runs each of the provided queries separately and
	   concatenates	their results.

       visit_select()
	     $sqldb->visit_select( $code_ref, %sql_clauses ) : @results
	     $sqldb->visit_select( %sql_clauses, $code_ref ) : @results

	   Unless passed a "union" argument pair, simply calls the superclass
	   method.  Runs each of the provided queries separately and
	   concatenates	their results.

	   To Do: This method doesn't yet munge	the column names retrived by
	   the later queries to	match the first.

       visit_select_rows()
	     $sqldb->visit_select_rows(	$code_ref, %sql_clauses	) : @results
	     $sqldb->visit_select_rows(	%sql_clauses, $code_ref	) : @results

	   Unless passed a "union" argument pair, simply calls the superclass
	   method.  Runs each of the provided queries separately and
	   concatenates	their results.

       fetchsub_select()
	     $sqldb->fetchsub_select( %sql_clauses ) : $coderef

	   Unless passed a "union" argument pair, simply calls the superclass
	   method.  Runs each of the provided queries separately and
	   concatenates	their results.

	   To Do: This method doesn't yet munge	the column names retrived by
	   the later queries to	match the first.

       fetchsub_select_rows()
	     $sqldb->fetchsub_select_rows( %sql_clauses	) : $coderef

	   Unless passed a "union" argument pair, simply calls the superclass
	   method.  Runs each of the provided queries separately and
	   concatenates	their results.

       sql_union()
	   Calls Carp::confess().

SEE ALSO
       See DBIx::SQLEngine for the overall interface and developer
       documentation.

       See DBIx::SQLEngine::Docs::ReadMe for general information about this
       distribution, including installation and	license	information.

perl v5.32.0			  2004-11SQLEngine::Driver::Trait::NoUnions(3)

NAME | SYNOPSIS | DESCRIPTION | REFERENCE | SEE ALSO

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