mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-26 17:41:59 +00:00
169 lines
4.6 KiB
Markdown
169 lines
4.6 KiB
Markdown
---
|
||
slug: /zh/sql-reference/statements/show
|
||
sidebar_position: 38
|
||
sidebar_label: SHOW
|
||
---
|
||
|
||
# SHOW 查询 {#show-queries}
|
||
|
||
## SHOW CREATE TABLE {#show-create-table}
|
||
|
||
``` sql
|
||
SHOW CREATE [TEMPORARY] [TABLE|DICTIONARY] [db.]table [INTO OUTFILE filename] [FORMAT format]
|
||
```
|
||
返回单个字符串类型的 ‘statement’列,其中只包含了一个值 - 用来创建指定对象的 `CREATE` 语句。
|
||
|
||
注意,如果使用该查询去获取系统表的 `CREATE` 语句,你得到的是一个虚构的语句,仅用来展示系统的表结构,而不能实际创建表。
|
||
|
||
## SHOW DATABASES {#show-databases}
|
||
|
||
``` sql
|
||
SHOW DATABASES [INTO OUTFILE filename] [FORMAT format]
|
||
```
|
||
|
||
打印所有的数据库列表,该查询等同于 `SELECT name FROM system.databases [INTO OUTFILE filename] [FORMAT format]`
|
||
|
||
## SHOW PROCESSLIST {#show-processlist}
|
||
|
||
``` sql
|
||
SHOW PROCESSLIST [INTO OUTFILE filename] [FORMAT format]
|
||
```
|
||
|
||
输出 [system.processes](../../operations/system-tables/processes.md#system_tables-processes)表的内容,包含有当前正在处理的请求列表,除了 `SHOW PROCESSLIST`查询。
|
||
|
||
|
||
`SELECT * FROM system.processes` 查询返回和当前请求相关的所有数据
|
||
|
||
|
||
提示 (在控制台执行):
|
||
|
||
``` bash
|
||
$ watch -n1 "clickhouse-client --query='SHOW PROCESSLIST'"
|
||
```
|
||
|
||
## SHOW TABLES {#show-tables}
|
||
|
||
显示表的清单
|
||
|
||
``` sql
|
||
SHOW [TEMPORARY] TABLES [{FROM | IN} <db>] [LIKE '<pattern>' | WHERE expr] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
|
||
```
|
||
|
||
如果未使用 `FROM` 字句,该查询返回当前数据库的所有表清单
|
||
|
||
可以用下面的方式获得和 `SHOW TABLES`一样的结果:
|
||
|
||
``` sql
|
||
SELECT name FROM system.tables WHERE database = <db> [AND name LIKE <pattern>] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
|
||
```
|
||
|
||
**示例**
|
||
|
||
下列查询获取最前面的2个位于`system`库中且表名包含 `co`的表。
|
||
|
||
``` sql
|
||
SHOW TABLES FROM system LIKE '%co%' LIMIT 2
|
||
```
|
||
|
||
``` text
|
||
┌─name───────────────────────────┐
|
||
│ aggregate_function_combinators │
|
||
│ collations │
|
||
└────────────────────────────────┘
|
||
```
|
||
|
||
## SHOW DICTIONARIES {#show-dictionaries}
|
||
|
||
以列表形式显示 [外部字典](../../sql-reference/dictionaries/external-dictionaries/external-dicts.md).
|
||
|
||
``` sql
|
||
SHOW DICTIONARIES [FROM <db>] [LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
|
||
```
|
||
|
||
如果 `FROM`字句没有指定,返回当前数据库的字典列表
|
||
|
||
可以通过下面的查询获取和 `SHOW DICTIONARIES`相同的结果:
|
||
|
||
``` sql
|
||
SELECT name FROM system.dictionaries WHERE database = <db> [AND name LIKE <pattern>] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
|
||
```
|
||
|
||
**示例**
|
||
|
||
下列查询获取最前面的2个位于 `system`库中且名称包含 `reg`的字典表。
|
||
|
||
``` sql
|
||
SHOW DICTIONARIES FROM db LIKE '%reg%' LIMIT 2
|
||
```
|
||
|
||
``` text
|
||
┌─name─────────┐
|
||
│ regions │
|
||
│ region_names │
|
||
└──────────────┘
|
||
```
|
||
|
||
## SHOW GRANTS {#show-grants-statement}
|
||
|
||
显示用户的权限
|
||
|
||
### 语法 {#show-grants-syntax}
|
||
|
||
``` sql
|
||
SHOW GRANTS [FOR user]
|
||
```
|
||
|
||
如果未指定用户,输出当前用户的权限
|
||
|
||
## SHOW CREATE USER {#show-create-user-statement}
|
||
|
||
显示 [user creation](../../sql-reference/statements/create.md#create-user-statement)用到的参数。
|
||
|
||
`SHOW CREATE USER` 不会输出用户的密码信息
|
||
|
||
### 语法 {#show-create-user-syntax}
|
||
|
||
``` sql
|
||
SHOW CREATE USER [name | CURRENT_USER]
|
||
```
|
||
|
||
## SHOW CREATE ROLE {#show-create-role-statement}
|
||
|
||
显示 [role creation](../../sql-reference/statements/create.md#create-role-statement) 中用到的参数。
|
||
|
||
### 语法 {#show-create-role-syntax}
|
||
|
||
``` sql
|
||
SHOW CREATE ROLE name
|
||
```
|
||
|
||
## SHOW CREATE ROW POLICY {#show-create-row-policy-statement}
|
||
|
||
显示 [row policy creation](../../sql-reference/statements/create.md#create-row-policy-statement)中用到的参数
|
||
|
||
### 语法 {#show-create-row-policy-syntax}
|
||
|
||
``` sql
|
||
SHOW CREATE [ROW] POLICY name ON [database.]table
|
||
```
|
||
|
||
## SHOW CREATE QUOTA {#show-create-quota-statement}
|
||
|
||
显示 [quota creation](../../sql-reference/statements/create.md#create-quota-statement)中用到的参数
|
||
|
||
### 语法 {#show-create-row-policy-syntax}
|
||
|
||
``` sql
|
||
SHOW CREATE QUOTA [name | CURRENT]
|
||
```
|
||
|
||
## SHOW CREATE SETTINGS PROFILE {#show-create-settings-profile-statement}
|
||
|
||
显示 [settings profile creation](../../sql-reference/statements/create.md#create-settings-profile-statement)中用到的参数
|
||
|
||
### 语法 {#show-create-row-policy-syntax}
|
||
|
||
``` sql
|
||
SHOW CREATE [SETTINGS] PROFILE name
|
||
```
|