How Do I Reset the AUTO_INCREMENT Value in MySQL?

MySQL AUTO_INCREMENT Counter Reset

This guide explains how to reset the AUTO_INCREMENT counter for a MySQL table column. The following SQL command resets the counter to 1:

<code class="language-sql">ALTER TABLE tablename AUTO_INCREMENT = 1;</code>

Replace tablename with the actual name of your table.

Impact of Different Storage Engines

The behavior of this command differs depending on the table's storage engine:

• InnoDB: You cannot set the AUTO_INCREMENT value lower than the highest existing value in the column. Attempting to do so will have no effect; the counter will remain unchanged, and no error will be reported.
• Aria: You can set the AUTO_INCREMENT to any value, but the next insertion will still use the next available value (maximum 1), effectively ignoring the manually set value.
• MyISAM: If the new AUTO_INCREMENT value is less than or equal to the highest existing value, it will be set to the current maximum plus one.

Dynamic AUTO_INCREMENT Reset

For dynamic resets (e.g., based on the maximum value in another table), use this query:

<code class="language-sql">ALTER TABLE tablename AUTO_INCREMENT = (SELECT MAX(column_name) FROM other_table) + 1;</code>

This sets the AUTO_INCREMENT to one more than the maximum value in column_name of other_table. Remember to replace tablename, column_name, and other_table with your specific table and column names.

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