How to Reset an Auto-Increment Sequence in PostgreSQL?

Resetting PostgreSQL Auto-Increment Sequences

PostgreSQL's auto-increment fields sometimes require a counter reset. This guide demonstrates how to force a PostgreSQL auto-increment field to a specific integer value.

The Solution: A Two-Step Process

Resetting the auto-increment counter involves these two steps:

1. Modifying the Table: Use the ALTER TABLE command to set the desired starting value for the auto-increment field:

<code class="language-sql">ALTER TABLE product AUTO_INCREMENT = 1453;</code>

This sets the product table's auto-increment sequence to begin at 1453.

2. Sequence Reset: Locate the sequence associated with your auto-increment column. PostgreSQL sequences typically follow the naming convention ${table}_${column}_seq. For instance, a product table with an id column would use the sequence product_id_seq. Reset this sequence using ALTER SEQUENCE:

<code class="language-sql">ALTER SEQUENCE product_id_seq RESTART WITH 1453;</code>

This ensures the sequence generates values starting from 1453.

Important Considerations:

A non-existent sequence will cause an error. To confirm the sequence name, use the ds command in the psql terminal to list all sequences. Alternatively, examine the auto-increment column's default constraint using d product. The nextval(...) call within the constraint will reveal the sequence name.

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