How does \Magento\Framework\DB\Adapter\Pdo\Mysql::getCheckSql() work?

dmitry_fedyuk · April 29, 2016, 9:16pm

Context: How does \Magento\Catalog\Model\ResourceModel\Product\Gallery::createBaseLoadSelect() work?

magento/magento2/blob/958164/lib/internal/Magento/Framework/DB/Adapter/Pdo/Mysql.php#L2931-L2940




/**
 * Generate fragment of SQL, that check condition and return true or false value
 *
 * @param \Zend_Db_Expr|\Magento\Framework\DB\Select|string $expression
 * @param string $true  true value
 * @param string $false false value
 * @return \Zend_Db_Expr
 */
public function getCheckSql($expression, $true, $false)

github.com

magento/magento2/blob/958164/lib/internal/Magento/Framework/DB/Adapter/Pdo/Mysql.php#L2941-L2946


{
    if ($expression instanceof \Zend_Db_Expr || $expression instanceof \Zend_Db_Select) {
        $expression = sprintf("IF((%s), %s, %s)", $expression, $true, $false);
    } else {
        $expression = sprintf("IF(%s, %s, %s)", $expression, $true, $false);
    }