how to execute complex mysql queries in laravel - php

Question

I have one below mysql query that is working fine but i want to run it laravel using prepare statement.
SET #sql = NULL;
SELECT GROUP_CONCAT(CONCAT("SELECT '",colname,":' AS 'Label',GROUP_CONCAT(JSON_UNQUOTE(JSON_EXTRACT(attr_details,'$.", colname,"'))) AS 'val' FROM mytable GROUP BY Label") SEPARATOR " UNION ")
INTO #sql
FROM
(WITH RECURSIVE data AS (
SELECT attr_details,JSON_VALUE(JSON_KEYS(attr_details), '$[0]') AS colname, 0 AS idx FROM mytable
UNION
SELECT attr_details,JSON_VALUE(JSON_KEYS(attr_details), CONCAT('$[', d.idx + 1, ']'))
AS colname, d.idx + 1 AS idx FROM data AS d
WHERE d.idx < JSON_LENGTH(JSON_KEYS(attr_details)) - 1
) SELECT colname
FROM data
GROUP BY colname) V;
PREPARE stmt FROM #sql;
EXECUTE stmt;;
Now i have tried to convert in larvel like below
$PDO=DB::connection('mysql')->getPdo();
$stmt = $PDO->prepare(<<<_OUT
SET #sql = NULL;
SELECT GROUP_CONCAT(CONCAT("SELECT '",colname,"' AS 'Label',GROUP_CONCAT(JSON_UNQUOTE(JSON_EXTRACT(attr_details,'$.", colname,"'))) AS 'val' FROM product_attributes GROUP BY Label") SEPARATOR " UNION ")
INTO #sql
FROM
(WITH RECURSIVE data AS (
SELECT attr_details,JSON_VALUE(JSON_KEYS(attr_details), '$[0]') AS colname, 0 AS idx FROM product_attributes
UNION
SELECT attr_details,JSON_VALUE(JSON_KEYS(attr_details), CONCAT('$[', d.idx + 1, ']'))
AS colname, d.idx + 1 AS idx FROM data AS d
WHERE d.idx < JSON_LENGTH(JSON_KEYS(attr_details)) - 1
) SELECT colname
FROM data
GROUP BY colname) V;
_OUT
);
$stmt->execute();
$result = $stmt->fetchAll();
echo "<pre>"; print_r($result); die;
I am getting this error "syntax error, unexpected 'SELECT' (T_STRING), expecting ')'",
Can anyone help me what i am doing wrong

Answer 1

Please check your quotes at first. In the code "SELECT GROUP_CONCAT(CONCAT("SELECT PHP recognizes that as complete string "SELECT GROUP_CONCAT(CONCAT(" and something undefined SELECT ' with the next string, without concatenation.
At least for me my IDE highlights your code as incorrect. To deal with various quotes try to use that approach
$stmt = $PDO->prepare(<<<_OUT
SELECT * FROM `table` WHERE "1";
_OUT
);
Try to write the request without #sql variable, without PREPARE stm and without EXECUTE stm. I think, PDO will deal with preparing and executing by itself.
$stmt = $PDO->prepare(<<<_OUT
SELECT GROUP_CONCAT() ...
FROM data
GROUP BY colname) V;
_OUT
);
$stmt->execute();
$stmt->fetchAll();
Try to use Laravel approach: DB::select(DB::raw($sql));

Answer 2

SELECT GROUP_CONCAT(CONCAT("SELECT
^-- this quote must be escaped like this: \"
PHP thinks that your SQL string ends there.
Check the other quotes as well.
Edit: Other option might be to wrap the whole SQL to single quotes (') and then just escape those inside the query (by \')