SELECT SUM(days) AS total_days
FROM (SELECT `days` FROM `Tbl_1` WHERE `emID`=0001
UNION ALL
SELECT `days` FROM `Tbl_2` WHERE `emID`=0001
UNION ALL
SELECT `days` FROM `Tbl_3` WHERE `emID`=0001) t
I want to sum all (days) column from my 3 tables with where clause. how should i do that?
SELECT SUM(days) AS total_days
FROM (SELECT `days` FROM `Tbl_1` WHERE `emID`=0001
UNION ALL
SELECT `days` FROM `Tbl_2` WHERE `emID`=0001
UNION ALL
SELECT `days` FROM `Tbl_3` WHERE `emID`=0001) t
SELECT SUM(column) as totaldays
FROM (
SELECT * FROM `tbl1` WHERE `column`='column_val'
UNION ALL
SELECT * FROM `tbl2` WHERE `column`='column_val'
UNION ALL
SELECT * FROM `tbl3` WHERE `column`='column_val'
) AS somealias