Question

Same as oracle diff: how to compare two tables? except in mysql.

Suppose I have two tables, t1 and t2 which are identical in layout but which may contain different data.

What’s the best way to diff these two tables?

To be more precise, I’m trying to figure out a simple SQL query that tells me if data from one row in t1 is different from the data from the corresponding row in t2

It appears I cannot use the intersect nor minus. When I try

SELECT * FROM robot intersect SELECT * FROM tbd_robot

I get an error code:

[Error Code: 1064, SQL State: 42000] You have an error in your SQL
syntax; check the manual that corresponds to your MySQL server version
for the right syntax to use near ‘SELECT * FROM tbd_robot’ at line 1

Am I doing something syntactically wrong? If not, is there another query I can use?

Edit: Also, I’m querying through a free version DbVisualizer. Not sure if that might be a factor.

Answer 1

INTERSECT needs to be emulated in MySQL:

SELECT  'robot' AS `set`, r.*
FROM    robot r
WHERE   ROW(r.col1, r.col2, …) NOT IN
        (
        SELECT  col1, col2, ...
        FROM    tbd_robot
        )
UNION ALL
SELECT  'tbd_robot' AS `set`, t.*
FROM    tbd_robot t
WHERE   ROW(t.col1, t.col2, …) NOT IN
        (
        SELECT  col1, col2, ...
        FROM    robot
        )