mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-17 03:42:48 +00:00
ad62e42229
* translate [select] section into Chinese to improve readability * trigger ci Co-authored-by: mikepop7 <> Co-authored-by: Ivan Blinkov <github@blinkov.ru>
63 lines
1.4 KiB
Markdown
63 lines
1.4 KiB
Markdown
---
|
|
toc_title: LIMIT
|
|
---
|
|
|
|
# LIMIT {#limit-clause}
|
|
|
|
`LIMIT m` 允许选择结果中起始的 `m` 行。
|
|
|
|
`LIMIT n, m` 允许选择个 `m` 从跳过第一个结果后的行 `n` 行。 与 `LIMIT m OFFSET n` 语法是等效的。
|
|
|
|
`n` 和 `m` 必须是非负整数。
|
|
|
|
如果没有 [ORDER BY](../../../sql-reference/statements/select/order-by.md) 子句显式排序结果，结果的行选择可能是任意的和非确定性的。
|
|
|
|
## LIMIT … WITH TIES 修饰符 {#limit-with-ties}
|
|
|
|
如果为 `LIMIT n[,m]` 设置了 `WITH TIES` ，并且声明了 `ORDER BY expr_list`, you will get in result first `n` or `n,m` rows and all rows with same `ORDER BY` fields values equal to row at position `n` for `LIMIT n` and `m` for `LIMIT n,m`.
|
|
|
|
此修饰符可以与： [ORDER BY … WITH FILL modifier](../../../sql-reference/statements/select/order-by.md#orderby-with-fill) 组合使用.
|
|
|
|
例如以下查询：
|
|
|
|
``` sql
|
|
SELECT * FROM (
|
|
SELECT number%50 AS n FROM numbers(100)
|
|
) ORDER BY n LIMIT 0,5
|
|
```
|
|
|
|
返回
|
|
|
|
``` text
|
|
┌─n─┐
|
|
│ 0 │
|
|
│ 0 │
|
|
│ 1 │
|
|
│ 1 │
|
|
│ 2 │
|
|
└───┘
|
|
```
|
|
|
|
单子执行了 `WITH TIES` 修饰符后
|
|
|
|
``` sql
|
|
SELECT * FROM (
|
|
SELECT number%50 AS n FROM numbers(100)
|
|
) ORDER BY n LIMIT 0,5 WITH TIES
|
|
```
|
|
|
|
则返回了以下的数据行
|
|
|
|
``` text
|
|
┌─n─┐
|
|
│ 0 │
|
|
│ 0 │
|
|
│ 1 │
|
|
│ 1 │
|
|
│ 2 │
|
|
│ 2 │
|
|
└───┘
|
|
```
|
|
|
|
cause row number 6 have same value “2” for field `n` as row number 5
|