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106 lines
3.0 KiB
Markdown
106 lines
3.0 KiB
Markdown
---
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machine_translated: true
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machine_translated_rev: b111334d6614a02564cf32f379679e9ff970d9b1
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toc_priority: 38
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toc_title: SHOW
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---
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# 显示查询 {#show-queries}
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## SHOW CREATE TABLE {#show-create-table}
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``` sql
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SHOW CREATE [TEMPORARY] [TABLE|DICTIONARY] [db.]table [INTO OUTFILE filename] [FORMAT format]
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```
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返回单 `String`-类型 ‘statement’ column, which contains a single value – the `CREATE` 用于创建指定对象的查询。
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## SHOW DATABASES {#show-databases}
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``` sql
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SHOW DATABASES [INTO OUTFILE filename] [FORMAT format]
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```
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打印所有数据库的列表。
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这个查询是相同的 `SELECT name FROM system.databases [INTO OUTFILE filename] [FORMAT format]`.
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## SHOW PROCESSLIST {#show-processlist}
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``` sql
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SHOW PROCESSLIST [INTO OUTFILE filename] [FORMAT format]
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```
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输出的内容 [系统。流程](../../operations/system_tables.md#system_tables-processes) 表，包含目前正在处理的查询列表，除了 `SHOW PROCESSLIST` 查询。
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该 `SELECT * FROM system.processes` 查询返回有关所有当前查询的数据。
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提示（在控制台中执行):
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``` bash
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$ watch -n1 "clickhouse-client --query='SHOW PROCESSLIST'"
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```
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## SHOW TABLES {#show-tables}
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显示表的列表。
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``` sql
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SHOW [TEMPORARY] TABLES [{FROM | IN} <db>] [LIKE '<pattern>' | WHERE expr] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
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```
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如果 `FROM` 如果未指定子句，则查询返回当前数据库中的表列表。
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你可以得到相同的结果 `SHOW TABLES` 通过以下方式进行查询:
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``` sql
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SELECT name FROM system.tables WHERE database = <db> [AND name LIKE <pattern>] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
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```
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**示例**
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下面的查询从表的列表中选择前两行 `system` 数据库，其名称包含 `co`.
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``` sql
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SHOW TABLES FROM system LIKE '%co%' LIMIT 2
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```
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``` text
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┌─name───────────────────────────┐
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│ aggregate_function_combinators │
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│ collations │
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└────────────────────────────────┘
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```
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## SHOW DICTIONARIES {#show-dictionaries}
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显示列表 [外部字典](../../sql_reference/dictionaries/external_dictionaries/external_dicts.md).
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``` sql
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SHOW DICTIONARIES [FROM <db>] [LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
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```
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如果 `FROM` 如果未指定子句，则查询从当前数据库返回字典列表。
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你可以得到相同的结果 `SHOW DICTIONARIES` 通过以下方式进行查询:
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``` sql
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SELECT name FROM system.dictionaries WHERE database = <db> [AND name LIKE <pattern>] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
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```
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**示例**
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下面的查询从表的列表中选择前两行 `system` 数据库，其名称包含 `reg`.
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``` sql
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SHOW DICTIONARIES FROM db LIKE '%reg%' LIMIT 2
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```
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``` text
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┌─name─────────┐
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│ regions │
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│ region_names │
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└──────────────┘
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```
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[原始文章](https://clickhouse.tech/docs/en/query_language/show/) <!--hide-->
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