how to merge two mysql tables with same structure

Question

I have 2 tables with same structure and same id (as primary key) but different data :

Now, I need to merge them and have something like this :

It is important to not change id of rows and not insert new records.

How can I do that using a MySQL query ?

Answer 1

Think you just need to performe an UPDATE query with an INNER JOIN of the two table. I assume id columns are realted so

UPDATE table1 a
INNER JOIN table2 b
ON a.id = b.id
SET a.fax = b.fax

Otherwise you can set a new table and take values by join two previous table as follow

INSERT INTO table3 (id, tel, fax) 
SELECT a.id, a.tel, b.fax
FROM table1 a
INNER JOIN table2 b
ON a.id = b.id

Answer 2

First, backup your data. Then, if you only want to end up with one table (and the primary keys match), then try this:

UPDATE `table1`
SET `table1`.`fax` = `table2`.`fax`
WHERE `table1`.`id` = `table2`.`id`;

If that doesn't work, it's a good thing you made a backup.

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