For PHP search, please

For PHP search instructions, please advise! Fields in Table A and Table B are numeric strings, for example, '2, 3, 6, 34, 23', '43, 35 '.... Now, we need to search for Table B using the table A field. if the field A is converted into an array and the likeB field is not found, if there is 3 in field, in field B, you can ask for PHP search instructions!
Fields in Table A and Table B are numeric strings, for example, '2, 3, 6, 34, 23', '43, 35 '....

Search for Table B using the table A field.

At first, we typed field a into an array and went to the likeB field. The result showed no. if field A contains 3, then field B contains, 33, and 43... All with 3 will be retrieved.

Therefore, a better solution is required!

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Like '2 ,'
------ Solution --------------------
When you save the data, you must include,
Constructed as follows:, 2, 4,

Then you can use like ', 3 ,'
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Compress field A into an array and remove field like B.
No, you know why.

However, it is correct to compress field A into an array.
Use find_in_set for comparison.
For example
Find_in_set ('3', '23, 33,43 ')
It won't match