Mysql update using a subquery

Post as a guest Name. Email Required, but never shown. The Overflow Blog. Stack Gives Back Safety in numbers: crowdsourcing data on nefarious IP addresses. Featured on Meta. New post summary designs on greatest hits now, everywhere else eventually. Visit chat. Linked 1. Summary : in this tutorial, we will show you how to use the MySQL subquery to write complex queries and explain the correlated subquery concept.

Also, a subquery can be nested within another subquery. A MySQL subquery is called an inner query while the query that contains the subquery is called an outer query. A subquery can be used anywhere that expression is used and must be closed in parentheses. For example, the following query uses a subquery to return the employees who work in the offices located in the USA. When executing the query, MySQL evaluates the subquery first and uses the result of the subquery for the outer query.

We will use the table payments in the sample database for the demonstration. The second is order , which stores the orders we receive from our customers, including the name of the wine ordered and the quantity ordered, among other information.

Suppose we want to obtain a list of wines for which we have never received an order. The query will look like this:. The subquery returns the names of all the wines for which we have received orders. Then the outer query, using the NOT IN operator, obtains the names of the wines never included in any order. SQL is as simple as it is powerful! If you want to brush up on some subquery concepts, I suggest the course SQL Basics where you can find a complete section on subqueries. This is very common; the idea is to insert the complete result set from a subquery or a SELECT statement into a table.

As an example, imagine we want to create invoices for all wine orders we received during the day. Below is a partial view of our invoice table:. If we simply add an INSERT clause before the query, we can insert the result of the query into the table wine , as we can see in the following example:.

The question is a unclear on how the tables are to actually related to each other. Of course, none of these will work if I have failed to understand the necessary logic. Improve this answer. Michael - sqlbot Michael - sqlbot Your answer worked and you understood my problem very well, thank you for your help — user Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password.

Post as a guest Name. Email Required, but never shown. The Overflow Blog.