Software Applications Programming Errors and solutions.

Method 1: update tab a set col1 = -1 where exists (select 1 from tab b where a.col2 = b.col2 and a.col3 = b.col3 and a.col3 = b.col4 ) Method 2: update tab a set (col1,col7,col8) = (select -1, col7,col8 from tab b where a.col2 = b.col2 and a.col3 = b.col3 and a.col3 = b.col4 ) where exists (select 1 from tab b where a.col2 = b.col2 and a.col3 = b.col3 and a.col3 = b.col4 ) Note: In Method 2 the sub-query must return only 1 row. set (col1,col7,col8) = (select -1, col7,col8 from tab b where a.col2 = b.col2 and a.col3 = b.col3 and a.col3 = b.col4 )