How to loop through all the tables on a database to update columns

Question

I\'m trying to update a column (in this case, a date) that is present on most of the tables on my database. Sadly, my database has more than 100 tables already created and f

Answer 1

One painless option would be to create a query which generates the UPDATE statements you want to run on all the tables:

SELECT CONCAT('UPDATE ', a.table_name, ' SET date = "2016-04-20" WHERE name = "Example";')
FROM information_schema.tables a
WHERE a.table_schema = 'YourDBNameHere'

You can copy the output from this query, paste it in the query editor, and run it.

Update:

As @PaulSpiegel pointed out, the above solution might be inconvenient if one be using an editor such as HeidiSQL, because it would require manually copying each record in the result set. Employing a trick using GROUP_CONCAT() would give a single string containing every desired UPDATE query in it:

SELECT GROUP_CONCAT(t.query SEPARATOR '; ')
FROM
(
    SELECT CONCAT('UPDATE ', a.table_name,
                  ' SET date = "2016-04-20" WHERE name = "Example";') AS query,
        '1' AS id
    FROM information_schema.tables a
    WHERE a.table_schema = 'YourDBNameHere'
) t
GROUP BY t.id