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MySQL-like group by statement on queries. It keeps only the first row of each set of rows where the given expressions evaluate to equal. [PostgreSQL Docs](https://www.postgresql.org/docs/9.5/static/sql-select.html#SQL-DISTINCT)
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## How it works
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```ruby
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distinct_on(*columns)
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```
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```ruby
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# SELECT DISTINCT ON ( "users"."name" ) "users".* FROM "users"
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User.distinct_on(:name).all
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```
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You can use where-like syntax to find more complex columns:
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```ruby
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# SELECT DISTINCT ON ( "users"."name" ) "users".* FROM "users"
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User.distinct_on(:name).all
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``` |
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\ No newline at end of file |
