SQL: Insert all other columns that update the same row as the primary key

In writing SQL, we often encounter such a problem. Every time you insert, you have to judge whether the data table already exists in this data, the so-called same data, except the primary key all columns are the same, no insert, there is update. In this situation, we do not know whether this column exists, so the simple insertion and update are problematic, so some people choose to delete the corresponding ID, and then all re-insert, the problem here is that the primary key from the increase, the deletion will produce a huge hole, not a good design.

Under MySQL, I used the following method:

Insert  into Case_law (case_id,laws_id) (select1,2fromwherenot  EXISTS (selectfromwhere case_id=1and laws_id=2)

A simple way to do this is to check for presence when inserting.

SQL: Insert all other columns that update the same row as the primary key