PHP MySQL数据透视表代码

Question

I've written this code for mysql pivot table:

SET @SQL = NULL;
SET @@group_concat_max_len = 6000;
SELECT GROUP_CONCAT( DISTINCT CONCAT( 'MAX(IF(questiondetails = \'', questiondetails, '\', answer, null)) AS \'', questiondetails, '\' ' )) INTO @SQL FROM wtfeedback;
SET @SQL = CONCAT( 'SELECT trialid, productsku, userkey, category, ', @SQL, ' FROM wtfeedback GROUP BY trialid' );
PREPARE stmt FROM @SQL;
EXECUTE stmt;

This works fine in Sequel Pro (mysql gui editor)

But when I paste into my php page to run this code it is showing a syntax error:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SET @@group_concat_max_len = 6000; SELECT GROUP_CONCAT( DISTINCT CONCAT( 'MAX(I' at line 3

I'm struggling to see what the error might be.

Any ideas ? Thanks in advance.

Answer 1

MySQL doesn't use '' to escape single quotes. If you want to embed single quotes in your in-sql strings, then use \':

CONCAT('MAX(IF(questiondetails = \'', questiondetails, '\', answer, null)) AS "', questiondetails, '" ')
                                 ^^---------------------^^