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35 lines
1.1 KiB
Markdown
35 lines
1.1 KiB
Markdown
---
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slug: /en/sql-reference/statements/select/qualify
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sidebar_label: QUALIFY
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---
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# QUALIFY Clause
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Allows filtering window functions results. It is similar to the [WHERE](../../../sql-reference/statements/select/where.md) clause, but the difference is that `WHERE` is performed before window functions evaluation, while `QUALIFY` is performed after it.
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It is possible to reference window functions results from `SELECT` clause in `QUALIFY` clause by their alias. Alternatively, `QUALIFY` clause can filter on results of additional window functions that are not returned in query results.
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## Limitations
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`QUALIFY` can’t be used if there are no window functions to evaluate. Use `WHERE` instead.
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## Examples
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Example:
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``` sql
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SELECT number, COUNT() OVER (PARTITION BY number % 3) AS partition_count
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FROM numbers(10)
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QUALIFY partition_count = 4
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ORDER BY number;
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```
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``` text
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┌─number─┬─partition_count─┐
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│ 0 │ 4 │
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│ 3 │ 4 │
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│ 6 │ 4 │
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│ 9 │ 4 │
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└────────┴─────────────────┘
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```
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