Convert JSON array in MySQL to rows

Question

UPDATE: This is now possible in MySQL 8 via the JSON_TABLE function: https://dev.mysql.com/doc/refman/8.0/en/json-table-functions.html

I\'m loving t

Answer 1

I was working in a report where there was a big json array list in one column. I modified the datamodel to store the relationship 1 to * instead of storing everything in one single column. For doing this process, I had to use a while in a stored procedure since I do not know the maximum size:

DROP PROCEDURE IF EXISTS `test`;

DELIMITER #

CREATE PROCEDURE `test`()
PROC_MAIN:BEGIN
DECLARE numNotes int;
DECLARE c int;
DECLARE pos varchar(10);

SET c = 0;
SET numNotes = (SELECT 
ROUND (   
        (
            LENGTH(debtor_master_notes)
            - LENGTH( REPLACE ( debtor_master_notes, "Id", "") ) 
        ) / LENGTH("Id")        
    ) AS countt FROM debtor_master
order by countt desc Limit 1);

DROP TEMPORARY TABLE IF EXISTS debtorTable;
CREATE TEMPORARY TABLE debtorTable(debtor_master_id int(11), json longtext, note int);
WHILE(c