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16 lines
716 B
Markdown
16 lines
716 B
Markdown
# Restarting Sequences When Truncating Tables
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PostgreSQL's
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[`truncate`](http://www.postgresql.org/docs/current/static/sql-truncate.html)
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feature is a handy way to clear out all the data from a table. If you use
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`truncate` on a table that has a `serial` primary key, you may notice that
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subsequent insertions keep counting up from where you left off. This is
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because the sequence the table is using hasn't been restarted. Sure, you can
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restart it manually or you can tell `truncate` to do it for you. By
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appending `restart identity` to the end of a `truncate` statement, Postgres
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will make sure to restart any associated sequences at `1`.
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```sql
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truncate pokemons, trainers, pokemons_trainers restart identity;
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```
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