Merge pull request #34716 from cnmade/PR202202181640

Translate zh/sql-reference/statements/alter/order-by
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Nikolay Degterinsky 2022-02-18 12:35:54 +03:00 committed by GitHub
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../../../../en/sql-reference/statements/alter/order-by.md

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---
toc_priority: 41
toc_title: ORDER BY
---
# 操作排序键表达式 {#manipulations-with-key-expressions}
```sql
ALTER TABLE [db].name [ON CLUSTER cluster] MODIFY ORDER BY new_expression
```
该命令将表的[排序键](../../../engines/table-engines/mergetree-family/mergetree.md)更改为 `new_expression`(表达式或表达式元组)。主键保持不变。
从某种意义上说,该命令是轻量级的,它只更改元数据。要保持数据部分行按排序键表达式排序的属性,您不能向排序键添加包含现有列的表达式(仅在相同的`ALTER`查询中由`ADD COLUMN`命令添加的列,没有默认的列值)。
!!! note "备注"
它只适用于[`MergeTree`](../../../engines/table-engines/mergetree-family/mergetree.md)表族(包括[replicated](../../../engines/table-engines/mergetree-family/replication.md)表)。