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

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

Answer 2

You can use this too:

update TABLE1 set BRANCH_ID = ( select BRANCH_ID from TABLE2 where TABLE1.SUBST_ID = TABLE2.SERIAL_ID)

but with my experience I can say that this way is so slow and not recommend it!

Answer 3

UPDATE TABLE2
       JOIN TABLE1
       ON TABLE1.SUBST_ID = TABLE2.SERIAL_ID
SET    TABLE2.BRANCH_ID = TABLE1.CREATED_ID 
WHERE TABLE2.BRANCH_ID IS NULL or TABLE2.BRANCH_ID='';

Answer 4

I think this should work

UPDATE secondTable
JOIN firsTable ON secondTable.SERIAL_ID = firsTable.SUBST_ID
SET BRANCH_ID = CREATED_ID

Answer 5

It is very simple to update using Inner join query in SQL .You can do it without using FROM clause. Here is an example :

    UPDATE customer_table c 

      INNER JOIN  
          employee_table e
          ON (c.city_id = e.city_id)  

    SET c.active = "Yes"

    WHERE c.city = "New york";

Answer 6

In addition to Tom's answer if you need to repeat the operation frequently and want to save time you can do:

UPDATE TABLE1
       JOIN TABLE2
       ON TABLE1.SUBST_ID = TABLE2.SERIAL_ID
SET    TABLE2.BRANCH_ID = TABLE1.CREATED_ID
WHERE TABLE2.BRANCH_ID IS NULL