How can I do three table JOINs in an UPDATE query?

Solution 1:

The answer is yes, you can.

Try it like this:

UPDATE TABLE_A a
    JOIN TABLE_B b ON a.join_col = b.join_col AND a.column_a = b.column_b
    JOIN TABLE_C c ON [condition]
SET a.column_c = a.column_c + 1

For a general update join:

UPDATE TABLEA a
JOIN TABLEB b ON a.join_colA = b.join_colB
SET a.columnToUpdate = [something]

Solution 2:

An alternative way of achieving the same result is not to use the JOIN keyword at all.

UPDATE TABLE_A, TABLE_B
SET TABLE_A.column_c = TABLE_B.column_c + 1
WHERE TABLE_A.join_col = TABLE_B.join_col

Solution 3:

Below is the update query which includes both JOIN and WHERE. In the same way, we can use multiple join/where clauses:

UPDATE opportunities_cstm oc JOIN opportunities o ON oc.id_c = o.id
 SET oc.forecast_stage_c = 'APX'
 WHERE o.deleted = 0
   AND o.sales_stage IN('ABC','PQR','XYZ')

Solution 4:

An alternative general plan:

UPDATE table A
JOIN table B ON {join fields}
JOIN table C ON {join fields}
JOIN {as many tables as you need}
SET A.column = {expression}

Example:

UPDATE person P
JOIN address A ON P.home_address_id = A.id
JOIN city C ON A.city_id = C.id
SET P.home_zip = C.zipcode;