How to Ignore Duplicate Keys When Inserting Data into MySQL?

Handling Duplicate Keys in MySQL: INSERT and ON DUPLICATE KEY

Inserting rows into a table with unique keys can pose a challenge when you need to avoid duplicate entries. The standard syntax for handling duplicates is to use INSERT ... ON DUPLICATE KEY UPDATE ..., which updates the existing row with the provided values. However, what if you don't want to perform any update and simply ignore duplicate insertions?

Fortunately, there's a solution for this scenario. Instead of using the UPDATE clause, you can use the following syntax:

INSERT ... ON DUPLICATE KEY UPDATE>

By assigning the primary key back to itself, this statement essentially does nothing when a duplicate key is encountered. The row will be skipped without any error or update action.

Another option, suitable if you don't care about potential errors, is to use INSERT IGNORE:

INSERT IGNORE INTO <table_name> (...) VALUES (...)

This statement will attempt to insert a row, ignoring any errors that may arise due to duplicate keys or other factors. However, it's important to note that using INSERT IGNORE can have certain limitations, such as autoincrement field exhaustion and possible foreign key errors.

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