SQL DatabaseLesson 60Free preview

SQL Auto Increment

This lesson is part of SQL · All levels

Summary

AUTO_INCREMENT automatically increases the value of the column each time a new line is added, and is generally paired to the primary key column. This way you don't have to fill out the ID manually so you reduce the risk of a value collision. The newly created id value can be read by the LAST_INSERT_ID function.

Key points

AUTO_INCREMENT automatically generates a sequential unique value for each new line.
It is usually paired with a primary key of the type INT or BIGINT.
The next value can be checked with SELECT.
You can set the starting value, for example AUTO_INCREMENT = 1000.
Only one column per table can have AUTO_INCREMENT.

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