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49 lines
1.2 KiB
Markdown
49 lines
1.2 KiB
Markdown
---
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slug: /en/sql-reference/aggregate-functions/reference/grouparray
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sidebar_position: 110
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---
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# groupArray
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Syntax: `groupArray(x)` or `groupArray(max_size)(x)`
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Creates an array of argument values.
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Values can be added to the array in any (indeterminate) order.
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The second version (with the `max_size` parameter) limits the size of the resulting array to `max_size` elements. For example, `groupArray(1)(x)` is equivalent to `[any (x)]`.
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In some cases, you can still rely on the order of execution. This applies to cases when `SELECT` comes from a subquery that uses `ORDER BY`.
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**Example**
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``` text
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SELECT * FROM default.ck;
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┌─id─┬─name─────┐
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│ 1 │ zhangsan │
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│ 1 │ ᴺᵁᴸᴸ │
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│ 1 │ lisi │
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│ 2 │ wangwu │
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└────┴──────────┘
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```
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Query:
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``` sql
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select id, groupArray(10)(name) from default.ck group by id;
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```
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Result:
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``` text
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┌─id─┬─groupArray(10)(name)─┐
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│ 1 │ ['zhangsan','lisi'] │
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│ 2 │ ['wangwu'] │
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└────┴──────────────────────┘
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```
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The groupArray function will remove ᴺᵁᴸᴸ value based on the above results.
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- Alias: `array_agg`.
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