Question

i store lists of ids inside fields (by list i mean val1,val2,val3,...), and i want to select rows from a table where the field has valX in the list.

i thought this would work, but apparently not 🙁

SELECT * 
  FROM userbulletins 
 WHERE 25 IN `currentMessages` 
    OR 25 IN `removedMessages` 
    OR 25 IN `readMessages`

currentMessages, removedMessages, and readMessages are fields with ids stored as lists

i’ve also tried

SELECT * 
 FROM userbulletins 
WHERE "25" IN(`currentMessages`)

both return nothing (and should return 1 row in my test db)

any idea what i’m doing wrong? or if this is even possible?
thanks!

Answer 1

If I understand correctly, you have a denormalized table where the currentMessages value can be “val1,val2,val3,…” and you want to find rows where 25 is one of those values? If so, use the FIND_IN_SET function:

WHERE FIND_IN_SET('25', `currentMessages`) > 0
   OR FIND_IN_SET('25', `removedMessages`) > 0
   OR FIND_IN_SET('25', `readMessages`) > 0

…but I really recommend normalizing your data to make querying easier.