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Database: ezcQuerySubSelect

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Class: ezcQuerySubSelect

Class to create subselects within queries. [source]
The ezcSubQuery used for creating correct subqueries inside ezcQuery object. Class holds a refenence to inclusive ezcQuery and transfer PDO related calls to it.
Example: 
 1.  $q = ezcDbInstance::get()->createSelectQuery();
 2.  $q2 = $q->subSelect();
 3.  
 4.  $q2->select( 'lastname' )->from( 'users' );
 5.  
 6.  // This will produce SQL:
 7.  // SELECT * FROM Greetings WHERE age > 10 AND user IN ( ( SELECT lastname FROM users ) )
 8.   $q->select( '*' )->from( 'Greetings' );
 9.      ->where( $q->expr->gt( 'age', 10 ),
10.               $q->expr->in( 'user', $q2 ) );
11.  
12.  $stmt = $q->prepare(); // $stmt is a normal PDOStatement
13.   $stmt->execute();

Parents

ezcQuery
   |
   --ezcQuerySelect
      |
      --ezcQuerySubSelect

Inherited Constants

From ezcQuerySelect:
ezcQuerySelect::ASC    Sort the result ascending.
ezcQuerySelect::DESC    Sort the result descending.

Member Variables

protected ezcQuery $outerQuery = null
Holds the outer query.

Inherited Member Variables

From ezcQuerySelect:
protected  ezcQuerySelect::$fromString
protected  ezcQuerySelect::$groupString
protected  ezcQuerySelect::$havingString
protected  ezcQuerySelect::$lastInvokedMethod
protected  ezcQuerySelect::$limitString
protected  ezcQuerySelect::$orderString
protected  ezcQuerySelect::$selectString
protected  ezcQuerySelect::$whereString
From ezcQuery:
protected  ezcQuery::$db
public  ezcQuery::$expr

Method Summary

public ezcQuerySubSelect __construct( $outer )
Constructs a new ezcQuery object.
public string bindParam( &$param, [$placeHolder = null], [$type = PDO::PARAM_STR], $param )
Binds the parameter $param to the specified variable name $placeHolder..
public string bindValue( $value, [$placeHolder = null], [$type = PDO::PARAM_STR] )
Binds the value $value to the specified variable name $placeHolder.
public string getQuery( )
Return string with SQL query for subselect.
public ezcQuerySubSelect subSelect( )
Returns ezcQuerySubSelect of deeper level.
public string __toString( )
Return SQL string for subselect.

Inherited Methods

From ezcQuerySelect :
public ezcQuerySelect ezcQuerySelect::__construct()
Constructs a new ezcQuery object.
public string ezcQuerySelect::alias()
Returns SQL to create an alias
protected ezcQuery ezcQuerySelect::doJoin()
Returns the SQL for a join or prepares $fromString for a join.
public ezcQuery ezcQuerySelect::from()
Select which tables you want to select from.
public static bool|string ezcQuerySelect::getDummyTableName()
Returns dummy table name.
public string ezcQuerySelect::getQuery()
Returns the complete select query string.
public ezcQuery ezcQuerySelect::groupBy()
Returns SQL that groups the result set by a given column.
public ezcQuery ezcQuerySelect::having()
Returns SQL that set having by a given expression.
public ezcQuery ezcQuerySelect::innerJoin()
Returns the SQL for an inner join or prepares $fromString for an inner join.
public ezcQuery ezcQuerySelect::leftJoin()
Returns the SQL for a left join or prepares $fromString for a left join.
public ezcQuerySelect ezcQuerySelect::limit()
Returns SQL that limits the result set.
public ezcQuery ezcQuerySelect::orderBy()
Returns SQL that orders the result set by a given column.
public void ezcQuerySelect::reset()
Resets the query object for reuse.
public ezcQuery ezcQuerySelect::rightJoin()
Returns the SQL for a right join or prepares $fromString for a right join.
public ezcQuery ezcQuerySelect::select()
Opens the query and selects which columns you want to return with the query.
public ezcQuery ezcQuerySelect::selectDistinct()
Opens the query and uses a distinct select on the columns you want to return with the query.
public ezcQuerySelect ezcQuerySelect::where()
Adds a where clause with logical expressions to the query.
From ezcQuery :
public ezcQuery ezcQuery::__construct()
Constructs a new ezcQuery that works on the database $db and with the aliases $aliases.
public static array ezcQuery::arrayFlatten()
Returns all the elements in $array as one large single dimensional array.
public string ezcQuery::bindParam()
Binds the parameter $param to the specified variable name $placeHolder..
public string ezcQuery::bindValue()
Binds the value $value to the specified variable name $placeHolder.
public void ezcQuery::doBind()
Performs binding of variables bound with bindValue and bindParam on the statement $stmt.
protected string ezcQuery::getIdentifier()
Returns the correct identifier for the alias $alias.
protected array(string) ezcQuery::getIdentifiers()
Returns the correct identifiers for the aliases found in $aliases.
public abstract string ezcQuery::getQuery()
Returns the query string for this query object.
public bool ezcQuery::hasAliases()
Returns true if this object has aliases.
public PDOStatement ezcQuery::prepare()
Returns a prepared statement from this query which can be used for execution.
protected void ezcQuery::resetBinds()
Resets the bound values and parameters to empty.
public void ezcQuery::setAliases()
Sets the aliases $aliases for this object.
public ezcQuerySubSelect ezcQuery::subSelect()
Returns the ezcQuerySubSelect query object.
public string ezcQuery::__toString()
Return SQL string for query.

Methods

__construct

ezcQuerySubSelect __construct( ezcQuery $outer )
Constructs a new ezcQuery object.

Parameters

Name Type Description
$outer ezcQuery reference to inclusive ezcQuery object.

Redefinition of

Method Description
ezcQuerySelect::__construct() Constructs a new ezcQuery object.

bindParam

string bindParam( &$param, [string $placeHolder = null], [ $type = PDO::PARAM_STR], &mixed $param )
Binds the parameter $param to the specified variable name $placeHolder..
This method use ezcQuery::bindParam() from the ezcQuery in which subselect included. Info about bounded parameters stored in ezcQuery.
The parameter $param specifies the variable that you want to bind. If $placeholder is not provided bind() will automatically create a placeholder for you. An automatic placeholder will be of the name 'ezcValue1', 'ezcValue2' etc.
Example: 
 1.  $value = 2;
 2.  $subSelect = $q->subSelect();
 3.  $subSelect->select('*')
 4.               ->from( 'table2' )
 5.                 ->where( $subSelect->expr->in('id', $subSelect->bindParam( $value )) );
 6.  
 7.  $q->select('*')
 8.      ->from( 'table' )
 9.        ->where ( $q->expr->eq( 'id', $subSelect ) );
10.  
11.  $stmt = $q->prepare(); // the parameter $value is bound to the query.
12.   $value = 4;
12.  $stmt->execute(); // subselect executed with 'id = 4'

Parameters

Name Type Description
$param &mixed  
$placeHolder string the name to bind with. The string must start with a colon ':'.
&$param  
$type  

See also:

ezcQuery::bindParam().

Redefinition of

Method Description
ezcQuery::bindParam() Binds the parameter $param to the specified variable name $placeHolder..

bindValue

string bindValue( mixed $value, [string $placeHolder = null], [ $type = PDO::PARAM_STR] )
Binds the value $value to the specified variable name $placeHolder.
This method use ezcQuery::bindValue() from the ezcQuery in which subselect included. Info about bounded parameters stored in ezcQuery.
The parameter $value specifies the value that you want to bind. If $placeholder is not provided bindValue() will automatically create a placeholder for you. An automatic placeholder will be of the name 'ezcValue1', 'ezcValue2' etc.
Example: 
 1.  $value = 2;
 2.  $subSelect = $q->subSelect();
 3.  $subSelect->select( name )
 4.               ->from( 'table2' )
 5.                 ->where(  $subSelect->expr->in('id', $subSelect->bindValue( $value )) );
 6.  
 7.  $q->select('*')
 8.      ->from( 'table1' )
 9.        ->where ( $q->expr->eq( 'name', $subSelect ) );
10.  
11.  $stmt = $q->prepare(); // the $value is bound to the query.
12.   $value = 4;
12.  $stmt->execute(); // subselect executed with 'id = 2'

Parameters

Name Type Description
$value mixed  
$placeHolder string the name to bind with. The string must start with a colon ':'.
$type  

See also:

ezcQuery::bindValue().

Redefinition of

Method Description
ezcQuery::bindValue() Binds the value $value to the specified variable name $placeHolder.

getQuery

string getQuery( )
Return string with SQL query for subselect.
Example: 
1.  $subSelect = $q->subSelect();
2.  $subSelect->select( name )->from( 'table2' );
3.  $q->select('*')
4.      ->from( 'table1' )
5.        ->where ( $q->expr->eq( 'name', $subSelect ) );
6.  $stmt = $q->prepare();
7.  $stmt->execute();

Redefinition of

Method Description
ezcQuerySelect::getQuery() Returns the complete select query string.

subSelect

ezcQuerySubSelect subSelect( )
Returns ezcQuerySubSelect of deeper level.
Used for making subselects inside subselects.
Example: 
 1.  $value = 2;
 2.  $subSelect = $q->subSelect();
 3.  $subSelect->select( name )
 4.               ->from( 'table2' )
 5.                 ->where( $subSelect->expr->in('id', $subSelect->bindValue( $value )) );
 6.  
 7.  $q->select(*)
 8.      ->from( 'table1' )
 9.        ->where ( $q->expr->eq( 'name', $subSelect ) );
10.  
11.  $stmt = $q->prepare(); // the $value is bound to the query.
12.   $value = 4;
12.  $stmt->execute(); // subselect executed with 'id = 2'

Redefinition of

Method Description
ezcQuery::subSelect() Returns the ezcQuerySubSelect query object.

__toString

string __toString( )
Return SQL string for subselect.
Typecasting to (string) should be used to make __toString() to be called with PHP 5.1. This will not be needed in PHP 5.2 and higher when this object is used in a string context.
Example: 
1.  $subSelect = $q->subSelect();
2.  $subSelect->select( name )->from( 'table2' );
3.  $q->select('*')
4.      ->from( 'table1' )
5.        ->where ( $q->expr->eq( 'name', (string)$subSelect ) );
6.  $stmt = $q->prepare();
7.  $stmt->execute();

Redefinition of

Method Description
ezcQuery::__toString() Return SQL string for query.

Last updated: Mon, 10 Nov 2008