Search using comma separated string

Question

So I think I completely misunderstood how FIND_IN_SET work

SELECT
    u.*, p.*
FROM
    users u
INNER JOIN profiles p ON p.user_id = u.id
WHERE
FIND_IN_SET('1,4,7', p.fruits)

This is not working as I thought it would.

1,4,7 represent the fruits selected by the user to search

p.fruits can look something like this 1,2,3,4,5,6,7 or 5,6,7 or 1,6,7 etc

Basically I want to find the records if any of the values in the first argument match any of the values in the second argument.

Is this possible?

Answer 1

if your p.fruits column is a varchar (which is not ideal for this situation, but if it is so) your query will be like

where …  ( concat(',', p.fruits , ‘,’) like ‘%,1,%’  
or concat(',', p.fruits , ‘,’) like ‘%,4,%’  or concat(',',p.fruits , ‘,’) like ‘%,7,%’ ) ... 

this won't be good for indexes since concatenation will disable usage of indexes .. better solution would be turn the column into a set and do the query like Michael's above .. or you can create a new table called user_fruits(fk_user_id int, fruit_id int) and create unique index on both fields and do the search in user_fruits table

Answer 2

Use FIELD instead of that.

FIELD(p.fruits, 1,4,7)

You should refer to this article:

10 things in MySQL (that won't work as expected)