Question

Ok I know my database is not normalized but in my case, It is not possible to normalize the data as each user has different access level with access rights, everytime I modify something and I need to delete the rows and insert back so I went for comma-separated values, here the issue is if I remove a particular group, regex doesn’t work, it throws me an error..am using php and the error goes like this

FUNCTION database_name.REGEXP_REPLACE does not exist

Table structure

allowed_group_ids
+----------------+
12345,34345,55454

My query, say for example $delete_id is 12345 or say 55454, I only pass one ID at a time and the id’s has no space in between and it’s a text field

UPDATE tbl_scripts SET allowed_group_ids = TRIM(BOTH ',' 
FROM REGEXP_REPLACE(allowed_group_ids, '(,(\s)?)?$detele_id', '')) 
WHERE system_id = {$_SESSION['system_id']}

So what’s wrong in here?

Answer 1

There is no such thing as regexp_replace in MySQL.

You could perform this query using regular replace:

UPDATE tbl_scripts SET allowed_group_ids = 
    trim(BOTH ',' FROM 
        replace(
            replace(allowed_group_ids, '$delete_id',','),
            ',,',
            ','
        )
    )
WHERE system_id = {$_SESSION['system_id']}

This first removes the ID, and removes any doubled-up commas, then removes any commas at the start/end of the string. This should be sufficient but you can add another replace to remove whitespace if necessary.

Update: SQL Fiddle shows the query in action