Sometimes we need to update a MYSQL table data based on other table data.
For example order_table field city is NULL, and users_data have a field city, we need to update order_table city from users_table city.
There are many ways to do this, but this query is the simplest one. This sample is for beginner users.
Here is working MySQL query to update MySQL table data from other table.
UPDATE
order_table LEFT JOIN users_table ON order_table.user_id=users_table.user_id
SET
order_table.city = user_table.city,
order_table.phone_number = user_table.phone_number
WHERE
order_table.city IS NULL OR order_table.phone_number IS NULL;
order_table field user_id and users_table field user_id must be indexed for performance.
table, the query checks the value in the performance column against the value in the performance column in the