syntax error with update query when join with some table

Question

Here is an API generated query - Not sure what is wrong.

UPDATE T123 
SET COL1 = 1, VER1 = VER1 + 1  
INNER JOIN  
    SELECT C1 
    FROM (SELECT T.NUM_FLD C1 FROM WAPTDT_123 T) TAB ON C1 = REQUEST_ID

gives me error

SQL command not properly ended

All columns are present in table, I believe something is wrong with the join and running this command on oracle.

EDIT

One more thing is, the

SELECT C1 
FROM (SELECT T.NUM_FLD C1 FROM WAPTDT_123 T) TAB

part of query is fixed as I am getting from some API.

Answer 1

Oracle does not support join in the update syntax:

UPDATE T123
    SET COL1 = 1,
        VER1 = VER1 + 1
    WHERE EXISTS (SELECT 1 FROM WAPTDT_123 T WHERE T123.REQUEST_ID = T.NUM_FLD);

This is standard SQL and should work in any database.

Your query has other problems as well . . . the subquery is not in parentheses, the inner join has no first table.

EDIT:

You can write this query with that subquery:

UPDATE T123
    SET COL1 = 1,
        VER1 = VER1 + 1
    WHERE T123.REQUEST_ID IN (SELECT C1 FROM ( SELECT T.NUM_FLD C1 FROM WAPTDT_123 T) TAB );

I switched this to an IN, just because that is another option. You could still use EXISTS.