difference between where_in and find_in_set

Question

I am working on a join query in which I have to get the data from a column which contain the comma separated values.like allowed_activity contain 1,2,3,4,5,6<

Answer 1

The following code is incorrect:

$this->db->where("FIND_IN_SET($activity_id, a.allowed_activity) !=",0);

I'm surprised this even runs without error, but one possibility is that it is generating a WHERE clause which compares a string against 0. Of course, they will never be equal, and so this will always be true.

If you want to call the native FIND_IN_SET() function, then you would need to use whereRaw():

$this->db->whereRaw("FIND_IN_SET($activity_id, a.allowed_activity) !=0");

Using WHERE IN (...) is incorrect here, because you have all the values in a single row, separated from commas. WHERE IN would make sense if you wanted to filter for certain values from many rows, each column having a single value.