/**
* Gets foreign key parameters
* @param string $table The table name as input parameter
* @param type $field The field name as input parameter
* @param type $constraintName The constraint name as output parameter
* @param type $refTable The reference table name as output parameter
* @param string $refField The reference table field name as output parameter
* @return boolean Returns true if foreign key infos where found
*/
private function GetForeignKey($table, $field, &$constraintName, &$refTable, &$refField)
{
$sql = new Sql\Builder($this);
$tbl = $sql->Table('information_schema.key_column_usage', array('TABLE_SCHEMA', 'TABLE_NAME', 'COLUMN_NAME', 'CONSTRAINT_NAME', 'REFERENCED_TABLE_NAME', 'REFERENCED_COLUMN_NAME'));
$cond = $sql->Equals($tbl->Field('TABLE_SCHEMA'), $sql->Value($this->dbName))->And_($sql->Equals($tbl->Field('TABLE_NAME'), $sql->Value($table)))->And_($sql->Equals($tbl->Field('COLUMN_NAME'), $sql->Value($field)))->And_($sql->IsNotNull($tbl->Field('REFERENCED_TABLE_NAME')));
$what = $sql->SelectList($tbl->Field('REFERENCED_TABLE_NAME'));
$what->Add($tbl->Field('REFERENCED_COLUMN_NAME'));
$what->Add($tbl->Field('CONSTRAINT_NAME'));
$select = $sql->Select(true, $what, $tbl, $cond);
$reader = $this->ExecuteQuery((string) $select);
if ($reader->Read()) {
$constraintName = (string) $reader->ByName('CONSTRAINT_NAME');
$refTable = (string) $reader->ByName('REFERENCED_TABLE_NAME');
$refField = (string) $reader->ByName('REFERENCED_COLUMN_NAME');
return true;
}
return false;
}
