How to Manually Control a PostgreSQL Sequence Value?

Manually Altering a Sequence in Postgres

Setting a Sequence to a Specific Value

Setting a sequence to a specific value can be achieved using the setval() function. This function takes a sequence name, a target value, and an optional third argument specifying whether to increment the target value or not.

Resolving the 'function setval(unknown) does not exist' Error

The error "function setval(unknown) does not exist" indicates that the sequence name specified in the setval() call is not valid. Double-check the sequence name and ensure it is correctly enclosed in single quotes.

Misplaced Parentheses in 'setval()' Usage

The incorrect usage of parentheses, as seen in SELECT setval('payments_id_seq'), 21, true;, is leading to the error. The correct syntax is SELECT setval('payments_id_seq', 21, true);. This change ensures that setval() receives the required arguments: sequence name, target value, and increment flag.

Using 'ALTER SEQUENCE'

While using ALTER SEQUENCE to modify the LASTVALUE of a sequence may seem like an alternative, it is not supported in Postgres. The recommended approach is to use the setval() function for reliable sequence manipulation.

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