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Merge pull request #24548 from kirillikoff/DOCSUP-9474-document-table-comments

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Docsup 9474: document table comments
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Kseniia Sumarokova 2021-05-31 11:11:27 +03:00 committed by GitHub
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63
docs/en/operations/system-tables/tables.md
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@ -54,6 +54,9 @@ Columns:
- `lifetime_bytes` ([Nullable](../../sql-reference/data-types/nullable.md)([UInt64](../../sql-reference/data-types/int-uint.md))) - Total number of bytes INSERTed since server start (only for `Buffer` tables).
- `comment` ([String](../../sql-reference/data-types/string.md)) - The comment for the table.
The `system.tables` table is used in `SHOW TABLES` query implementation.
**Example**
@ -65,47 +68,53 @@ SELECT * FROM system.tables LIMIT 2 FORMAT Vertical;
```text
Row 1:
──────
database: system
name: aggregate_function_combinators
uuid: 00000000-0000-0000-0000-000000000000
engine: SystemAggregateFunctionCombinators
database: base
name: t1
uuid: 81b1c20a-b7c6-4116-a2ce-7583fb6b6736
engine: MergeTree
is_temporary: 0
data_paths: []
metadata_path: /var/lib/clickhouse/metadata/system/aggregate_function_combinators.sql
metadata_modification_time: 1970-01-01 03:00:00
data_paths: ['/var/lib/clickhouse/store/81b/81b1c20a-b7c6-4116-a2ce-7583fb6b6736/']
metadata_path: /var/lib/clickhouse/store/461/461cf698-fd0b-406d-8c01-5d8fd5748a91/t1.sql
metadata_modification_time: 2021-01-25 19:14:32
dependencies_database: []
dependencies_table: []
create_table_query:
engine_full:
create_table_query: CREATE TABLE base.t1 (`n` UInt64) ENGINE = MergeTree ORDER BY n SETTINGS index_granularity = 8192
engine_full: MergeTree ORDER BY n SETTINGS index_granularity = 8192
partition_key:
sorting_key:
primary_key:
sorting_key: n
primary_key: n
sampling_key:
storage_policy:
total_rows: ᴺᵁᴸᴸ
total_bytes: ᴺᵁᴸᴸ
storage_policy: default
total_rows: 1
total_bytes: 99
lifetime_rows: ᴺᵁᴸᴸ
lifetime_bytes: ᴺᵁᴸᴸ
comment:
Row 2:
──────
database: system
name: asynchronous_metrics
database: default
name: 53r93yleapyears
uuid: 00000000-0000-0000-0000-000000000000
engine: SystemAsynchronousMetrics
engine: MergeTree
is_temporary: 0
data_paths: []
metadata_path: /var/lib/clickhouse/metadata/system/asynchronous_metrics.sql
metadata_modification_time: 1970-01-01 03:00:00
data_paths: ['/var/lib/clickhouse/data/default/53r93yleapyears/']
metadata_path: /var/lib/clickhouse/metadata/default/53r93yleapyears.sql
metadata_modification_time: 2020-09-23 09:05:36
dependencies_database: []
dependencies_table: []
create_table_query:
engine_full:
create_table_query: CREATE TABLE default.`53r93yleapyears` (`id` Int8, `febdays` Int8) ENGINE = MergeTree ORDER BY id SETTINGS index_granularity = 8192
engine_full: MergeTree ORDER BY id SETTINGS index_granularity = 8192
partition_key:
sorting_key:
primary_key:
sorting_key: id
primary_key: id
sampling_key:
storage_policy:
total_rows: ᴺᵁᴸᴸ
total_bytes: ᴺᵁᴸᴸ
storage_policy: default
total_rows: 2
total_bytes: 155
lifetime_rows: ᴺᵁᴸᴸ
lifetime_bytes: ᴺᵁᴸᴸ
comment:
```
[Original article](https://clickhouse.tech/docs/en/operations/system_tables/tables) <!--hide-->

36
docs/en/sql-reference/statements/create/table.md
View File

@ -354,3 +354,39 @@ SELECT * FROM base.t1;
│ 3 │
└───┘
```
## COMMENT Clause {#comment-table}
You can add a comment to the table when you creating it.
!!!note "Note"
The comment is supported for all table engines except [Kafka](../../../engines/table-engines/integrations/kafka.md), [RabbitMQ](../../../engines/table-engines/integrations/rabbitmq.md) and [EmbeddedRocksDB](../../../engines/table-engines/integrations/embedded-rocksdb.md).
**Syntax**
``` sql
CREATE TABLE db.table_name
(
name1 type1, name2 type2, ...
)
ENGINE = engine
COMMENT 'Comment'
```
**Example**
Query:
``` sql
CREATE TABLE t1 (x String) ENGINE = Memory COMMENT 'The temporary table';
SELECT name, comment FROM system.tables WHERE name = 't1';
```
Result:
```text
┌─name─┬─comment─────────────┐
│ t1 │ The temporary table │
└──────┴─────────────────────┘
```

62
docs/ru/operations/system-tables/tables.md
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@ -39,6 +39,8 @@
- `lifetime_bytes` ([Nullable](../../sql-reference/data-types/nullable.md)([UInt64](../../sql-reference/data-types/int-uint.md))) - общее количество байт, добавленных оператором `INSERT` с момента запуска сервера (только для таблиц `Buffer`).
- `comment` ([String](../../sql-reference/data-types/string.md)) — комментарий к таблице.
Таблица `system.tables` используется при выполнении запроса `SHOW TABLES`.
**Пример**
@ -50,45 +52,51 @@ SELECT * FROM system.tables LIMIT 2 FORMAT Vertical;
```text
Row 1:
──────
database: system
name: aggregate_function_combinators
uuid: 00000000-0000-0000-0000-000000000000
engine: SystemAggregateFunctionCombinators
database: base
name: t1
uuid: 81b1c20a-b7c6-4116-a2ce-7583fb6b6736
engine: MergeTree
is_temporary: 0
data_paths: []
metadata_path: /var/lib/clickhouse/metadata/system/aggregate_function_combinators.sql
metadata_modification_time: 1970-01-01 03:00:00
data_paths: ['/var/lib/clickhouse/store/81b/81b1c20a-b7c6-4116-a2ce-7583fb6b6736/']
metadata_path: /var/lib/clickhouse/store/461/461cf698-fd0b-406d-8c01-5d8fd5748a91/t1.sql
metadata_modification_time: 2021-01-25 19:14:32
dependencies_database: []
dependencies_table: []
create_table_query:
engine_full:
create_table_query: CREATE TABLE base.t1 (`n` UInt64) ENGINE = MergeTree ORDER BY n SETTINGS index_granularity = 8192
engine_full: MergeTree ORDER BY n SETTINGS index_granularity = 8192
partition_key:
sorting_key:
primary_key:
sorting_key: n
primary_key: n
sampling_key:
storage_policy:
total_rows: ᴺᵁᴸᴸ
total_bytes: ᴺᵁᴸᴸ
storage_policy: default
total_rows: 1
total_bytes: 99
lifetime_rows: ᴺᵁᴸᴸ
lifetime_bytes: ᴺᵁᴸᴸ
comment:
Row 2:
──────
database: system
name: asynchronous_metrics
database: default
name: 53r93yleapyears
uuid: 00000000-0000-0000-0000-000000000000
engine: SystemAsynchronousMetrics
engine: MergeTree
is_temporary: 0
data_paths: []
metadata_path: /var/lib/clickhouse/metadata/system/asynchronous_metrics.sql
metadata_modification_time: 1970-01-01 03:00:00
data_paths: ['/var/lib/clickhouse/data/default/53r93yleapyears/']
metadata_path: /var/lib/clickhouse/metadata/default/53r93yleapyears.sql
metadata_modification_time: 2020-09-23 09:05:36
dependencies_database: []
dependencies_table: []
create_table_query:
engine_full:
create_table_query: CREATE TABLE default.`53r93yleapyears` (`id` Int8, `febdays` Int8) ENGINE = MergeTree ORDER BY id SETTINGS index_granularity = 8192
engine_full: MergeTree ORDER BY id SETTINGS index_granularity = 8192
partition_key:
sorting_key:
primary_key:
sorting_key: id
primary_key: id
sampling_key:
storage_policy:
total_rows: ᴺᵁᴸᴸ
total_bytes: ᴺᵁᴸᴸ
storage_policy: default
total_rows: 2
total_bytes: 155
lifetime_rows: ᴺᵁᴸᴸ
lifetime_bytes: ᴺᵁᴸᴸ
comment:
```

35
docs/ru/sql-reference/statements/create/table.md
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@ -346,4 +346,39 @@ SELECT * FROM base.t1;
└───┘
```
## Секция COMMENT {#comment-table}
Вы можете добавить комментарий к таблице при ее создании.
!!!note "Замечание"
Комментарий поддерживается для всех движков таблиц, кроме [Kafka](../../../engines/table-engines/integrations/kafka.md), [RabbitMQ](../../../engines/table-engines/integrations/rabbitmq.md) и [EmbeddedRocksDB](../../../engines/table-engines/integrations/embedded-rocksdb.md).
**Синтаксис**
``` sql
CREATE TABLE db.table_name
(
name1 type1, name2 type2, ...
)
ENGINE = engine
COMMENT 'Comment'
```
**Пример**
Запрос:
``` sql
CREATE TABLE t1 (x String) ENGINE = Memory COMMENT 'The temporary table';
SELECT name, comment FROM system.tables WHERE name = 't1';
```
Результат:
```text
┌─name─┬─comment─────────────┐
│ t1 │ The temporary table │
└──────┴─────────────────────┘
```
<!--hide-->