Question

Trying to create a mysql query that will do the following:

For each record within Table 1, find a matching record in Table 2 where column A & B of Table 1 match column Y & Z of Table 2.

Once a match is found, grab column X value from Table 2 record and insert that value into column C of the original record in Table 1.

I hope that makes sense.

How the heck do I do that?

Answer 1

Use a multi-table update, just without modifying any columns from Table 2, as follows:

UPDATE Table1 T1, Table2 T2
SET T1.C = T2.X
WHERE T1.A = T2.Y AND T1.B = T2.Z;