MySQL update table based on another tables value

Question

I have a two tables,

Here is my first table,

ID      SUBST_ID        CREATED_ID
1       031938          TEST123
2       930111          COOL123
3             


        

Answer 1

Using INNER JOIN:

UPDATE TABLE1
INNER JOIN TABLE2 ON TABLE1.SUBST_ID = TABLE2.SERIAL_ID
SET TABLE2.BRANCH_ID = TABLE1.CREATED_ID;

Another alternative solution like below: Here I am using WHERE clause instead of JOIN

UPDATE 
    TABLE1,
    TABLE2
WHERE
    TABLE1.SUBST_ID = TABLE2.SERIAL_ID
SET 
    TABLE2.BRANCH_ID = TABLE1.CREATED_ID;