PHP Search wording please

Help PHP Search wording please expert guidance!
A and B table fields are numeric class strings: such as ' 2,3,6,34,23 ', ' 43,23,8,35 ' ....

Now to use a table field to search for B, please expert guidance under

Start is to put a field into the Likeb field, the results found no, if there is 3 in a field, then the B field 23,33,43 ... With 3 will be retrieved.

So ask for a better solution!

------Solution--------------------
Like ' 2, '
------Solution--------------------
When you save the data, it must be preceded and
Constructed like this:, 2,,4,

Then you use like ', 3, '
------Solution--------------------
Put a field into a group like B field
It's not going to work, because you know it.

But it's right to make a field into a group.
You can use Find_in_set when you compare.
Like what
Find_in_set (' 3 ', ' 23,33,43 ')
will not be matched to

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