MariaDB Update IF NOT EXISTS
If we want to do a MariaDB update operation under such conditions (IF NOT EXISTS or WHERE NOT EXISTS), you cannot directly use the respective clauses with the UPDATE statement. On the other hand, using subqueries and conditional logic can achieve the same functionality.
Example: Let’s update the email of a user only if there is no other user with the same email.
UPDATE Users SET email = 'new_email@gmail.com' WHERE user_id = 1
AND NOT EXISTS ( SELECT 1 FROM Users WHERE email = 'new_email@example.com' AND user_id != 1)
Output:
Update Email
Explanation:
- We’re updating the email for the user with id equal to 1.
- The NOT EXISTS subquery checks if there are no other users with the same email. If no such users exist, the condition is true, and the update operation proceeds.
- If there are other users with the same email, the condition evaluates to false, and the update operation does not occur for this user.
How to Insert if Not Exists in MariaDB
When managing a database, the need often arises to either insert a new record or update an existing one. MariaDB provides a powerful tool to handle this situation efficiently: the SQL IF NOT EXISTS clause. This clause allows us to perform an INSERT operation only if the record does not already exist, or an UPDATE operation if it does. In this article, we will explore how to use the SQL IF NOT EXISTS clause in MariaDB to insert a record if not present otherwise update the record with the help of examples and so on.