mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-14 03:25:15 +00:00
513 lines
13 KiB
Markdown
513 lines
13 KiB
Markdown
---
|
||
slug: /en/sql-reference/statements/show
|
||
sidebar_position: 37
|
||
sidebar_label: SHOW
|
||
---
|
||
|
||
# SHOW Statements
|
||
|
||
## SHOW CREATE TABLE
|
||
|
||
``` sql
|
||
SHOW CREATE [TEMPORARY] [TABLE|DICTIONARY|VIEW] [db.]table|view [INTO OUTFILE filename] [FORMAT format]
|
||
```
|
||
|
||
Returns a single `String`-type ‘statement’ column, which contains a single value – the `CREATE` query used for creating the specified object.
|
||
|
||
Note that if you use this statement to get `CREATE` query of system tables, you will get a *fake* query, which only declares table structure, but cannot be used to create table.
|
||
|
||
## SHOW DATABASES
|
||
|
||
Prints a list of all databases.
|
||
|
||
```sql
|
||
SHOW DATABASES [LIKE | ILIKE | NOT LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE filename] [FORMAT format]
|
||
```
|
||
|
||
This statement is identical to the query:
|
||
|
||
```sql
|
||
SELECT name FROM system.databases [WHERE name LIKE | ILIKE | NOT LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE filename] [FORMAT format]
|
||
```
|
||
|
||
### Examples
|
||
|
||
Getting database names, containing the symbols sequence 'de' in their names:
|
||
|
||
``` sql
|
||
SHOW DATABASES LIKE '%de%'
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─name────┐
|
||
│ default │
|
||
└─────────┘
|
||
```
|
||
|
||
Getting database names, containing symbols sequence 'de' in their names, in the case insensitive manner:
|
||
|
||
``` sql
|
||
SHOW DATABASES ILIKE '%DE%'
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─name────┐
|
||
│ default │
|
||
└─────────┘
|
||
```
|
||
|
||
Getting database names, not containing the symbols sequence 'de' in their names:
|
||
|
||
``` sql
|
||
SHOW DATABASES NOT LIKE '%de%'
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─name───────────────────────────┐
|
||
│ _temporary_and_external_tables │
|
||
│ system │
|
||
│ test │
|
||
│ tutorial │
|
||
└────────────────────────────────┘
|
||
```
|
||
|
||
Getting the first two rows from database names:
|
||
|
||
``` sql
|
||
SHOW DATABASES LIMIT 2
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─name───────────────────────────┐
|
||
│ _temporary_and_external_tables │
|
||
│ default │
|
||
└────────────────────────────────┘
|
||
```
|
||
|
||
### See Also
|
||
|
||
- [CREATE DATABASE](https://clickhouse.com/docs/en/sql-reference/statements/create/database/#query-language-create-database)
|
||
|
||
## SHOW PROCESSLIST
|
||
|
||
``` sql
|
||
SHOW PROCESSLIST [INTO OUTFILE filename] [FORMAT format]
|
||
```
|
||
|
||
Outputs the content of the [system.processes](../../operations/system-tables/processes.md#system_tables-processes) table, that contains a list of queries that is being processed at the moment, excepting `SHOW PROCESSLIST` queries.
|
||
|
||
The `SELECT * FROM system.processes` query returns data about all the current queries.
|
||
|
||
Tip (execute in the console):
|
||
|
||
``` bash
|
||
$ watch -n1 "clickhouse-client --query='SHOW PROCESSLIST'"
|
||
```
|
||
|
||
## SHOW TABLES
|
||
|
||
Displays a list of tables.
|
||
|
||
```sql
|
||
SHOW [TEMPORARY] TABLES [{FROM | IN} <db>] [LIKE | ILIKE | NOT LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
|
||
```
|
||
|
||
If the `FROM` clause is not specified, the query returns the list of tables from the current database.
|
||
|
||
This statement is identical to the query:
|
||
|
||
```sql
|
||
SELECT name FROM system.tables [WHERE name LIKE | ILIKE | NOT LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
|
||
```
|
||
|
||
### Examples
|
||
|
||
Getting table names, containing the symbols sequence 'user' in their names:
|
||
|
||
``` sql
|
||
SHOW TABLES FROM system LIKE '%user%'
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─name─────────────┐
|
||
│ user_directories │
|
||
│ users │
|
||
└──────────────────┘
|
||
```
|
||
|
||
Getting table names, containing sequence 'user' in their names, in the case insensitive manner:
|
||
|
||
``` sql
|
||
SHOW TABLES FROM system ILIKE '%USER%'
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─name─────────────┐
|
||
│ user_directories │
|
||
│ users │
|
||
└──────────────────┘
|
||
```
|
||
|
||
Getting table names, not containing the symbol sequence 's' in their names:
|
||
|
||
``` sql
|
||
SHOW TABLES FROM system NOT LIKE '%s%'
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─name─────────┐
|
||
│ metric_log │
|
||
│ metric_log_0 │
|
||
│ metric_log_1 │
|
||
└──────────────┘
|
||
```
|
||
|
||
Getting the first two rows from table names:
|
||
|
||
``` sql
|
||
SHOW TABLES FROM system LIMIT 2
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─name───────────────────────────┐
|
||
│ aggregate_function_combinators │
|
||
│ asynchronous_metric_log │
|
||
└────────────────────────────────┘
|
||
```
|
||
|
||
### See Also
|
||
|
||
- [Create Tables](https://clickhouse.com/docs/en/getting-started/tutorial/#create-tables)
|
||
- [SHOW CREATE TABLE](https://clickhouse.com/docs/en/sql-reference/statements/show/#show-create-table)
|
||
|
||
## SHOW DICTIONARIES
|
||
|
||
Displays a list of [Dictionaries](../../sql-reference/dictionaries/external-dictionaries/external-dicts.md).
|
||
|
||
``` sql
|
||
SHOW DICTIONARIES [FROM <db>] [LIKE '<pattern>'] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
|
||
```
|
||
|
||
If the `FROM` clause is not specified, the query returns the list of dictionaries from the current database.
|
||
|
||
You can get the same results as the `SHOW DICTIONARIES` query in the following way:
|
||
|
||
``` sql
|
||
SELECT name FROM system.dictionaries WHERE database = <db> [AND name LIKE <pattern>] [LIMIT <N>] [INTO OUTFILE <filename>] [FORMAT <format>]
|
||
```
|
||
|
||
**Example**
|
||
|
||
The following query selects the first two rows from the list of tables in the `system` database, whose names contain `reg`.
|
||
|
||
``` sql
|
||
SHOW DICTIONARIES FROM db LIKE '%reg%' LIMIT 2
|
||
```
|
||
|
||
``` text
|
||
┌─name─────────┐
|
||
│ regions │
|
||
│ region_names │
|
||
└──────────────┘
|
||
```
|
||
|
||
## SHOW GRANTS
|
||
|
||
Shows privileges for a user.
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW GRANTS [FOR user1 [, user2 ...]]
|
||
```
|
||
|
||
If user is not specified, the query returns privileges for the current user.
|
||
|
||
## SHOW CREATE USER
|
||
|
||
Shows parameters that were used at a [user creation](../../sql-reference/statements/create/user.md).
|
||
|
||
`SHOW CREATE USER` does not output user passwords.
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW CREATE USER [name1 [, name2 ...] | CURRENT_USER]
|
||
```
|
||
|
||
## SHOW CREATE ROLE
|
||
|
||
Shows parameters that were used at a [role creation](../../sql-reference/statements/create/role.md).
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW CREATE ROLE name1 [, name2 ...]
|
||
```
|
||
|
||
## SHOW CREATE ROW POLICY
|
||
|
||
Shows parameters that were used at a [row policy creation](../../sql-reference/statements/create/row-policy.md).
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW CREATE [ROW] POLICY name ON [database1.]table1 [, [database2.]table2 ...]
|
||
```
|
||
|
||
## SHOW CREATE QUOTA
|
||
|
||
Shows parameters that were used at a [quota creation](../../sql-reference/statements/create/quota.md).
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW CREATE QUOTA [name1 [, name2 ...] | CURRENT]
|
||
```
|
||
|
||
## SHOW CREATE SETTINGS PROFILE
|
||
|
||
Shows parameters that were used at a [settings profile creation](../../sql-reference/statements/create/settings-profile.md).
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW CREATE [SETTINGS] PROFILE name1 [, name2 ...]
|
||
```
|
||
|
||
## SHOW USERS
|
||
|
||
Returns a list of [user account](../../operations/access-rights.md#user-account-management) names. To view user accounts parameters, see the system table [system.users](../../operations/system-tables/users.md#system_tables-users).
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW USERS
|
||
```
|
||
|
||
## SHOW ROLES
|
||
|
||
Returns a list of [roles](../../operations/access-rights.md#role-management). To view another parameters, see system tables [system.roles](../../operations/system-tables/roles.md#system_tables-roles) and [system.role_grants](../../operations/system-tables/role-grants.md#system_tables-role_grants).
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW [CURRENT|ENABLED] ROLES
|
||
```
|
||
## SHOW PROFILES
|
||
|
||
Returns a list of [setting profiles](../../operations/access-rights.md#settings-profiles-management). To view user accounts parameters, see the system table [settings_profiles](../../operations/system-tables/settings_profiles.md#system_tables-settings_profiles).
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW [SETTINGS] PROFILES
|
||
```
|
||
|
||
## SHOW POLICIES
|
||
|
||
Returns a list of [row policies](../../operations/access-rights.md#row-policy-management) for the specified table. To view user accounts parameters, see the system table [system.row_policies](../../operations/system-tables/row_policies.md#system_tables-row_policies).
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW [ROW] POLICIES [ON [db.]table]
|
||
```
|
||
|
||
## SHOW QUOTAS
|
||
|
||
Returns a list of [quotas](../../operations/access-rights.md#quotas-management). To view quotas parameters, see the system table [system.quotas](../../operations/system-tables/quotas.md#system_tables-quotas).
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW QUOTAS
|
||
```
|
||
|
||
## SHOW QUOTA
|
||
|
||
Returns a [quota](../../operations/quotas.md) consumption for all users or for current user. To view another parameters, see system tables [system.quotas_usage](../../operations/system-tables/quotas_usage.md#system_tables-quotas_usage) and [system.quota_usage](../../operations/system-tables/quota_usage.md#system_tables-quota_usage).
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW [CURRENT] QUOTA
|
||
```
|
||
## SHOW ACCESS
|
||
|
||
Shows all [users](../../operations/access-rights.md#user-account-management), [roles](../../operations/access-rights.md#role-management), [profiles](../../operations/access-rights.md#settings-profiles-management), etc. and all their [grants](../../sql-reference/statements/grant.md#grant-privileges).
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW ACCESS
|
||
```
|
||
## SHOW CLUSTER(s)
|
||
|
||
Returns a list of clusters. All available clusters are listed in the [system.clusters](../../operations/system-tables/clusters.md) table.
|
||
|
||
:::note
|
||
`SHOW CLUSTER name` query displays the contents of system.clusters table for this cluster.
|
||
:::
|
||
|
||
### Syntax
|
||
|
||
``` sql
|
||
SHOW CLUSTER '<name>'
|
||
SHOW CLUSTERS [LIKE|NOT LIKE '<pattern>'] [LIMIT <N>]
|
||
```
|
||
### Examples
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
SHOW CLUSTERS;
|
||
```
|
||
|
||
Result:
|
||
|
||
```text
|
||
┌─cluster──────────────────────────────────────┐
|
||
│ test_cluster_two_shards │
|
||
│ test_cluster_two_shards_internal_replication │
|
||
│ test_cluster_two_shards_localhost │
|
||
│ test_shard_localhost │
|
||
│ test_shard_localhost_secure │
|
||
│ test_unavailable_shard │
|
||
└──────────────────────────────────────────────┘
|
||
```
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
SHOW CLUSTERS LIKE 'test%' LIMIT 1;
|
||
```
|
||
|
||
Result:
|
||
|
||
```text
|
||
┌─cluster─────────────────┐
|
||
│ test_cluster_two_shards │
|
||
└─────────────────────────┘
|
||
```
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
SHOW CLUSTER 'test_shard_localhost' FORMAT Vertical;
|
||
```
|
||
|
||
Result:
|
||
|
||
```text
|
||
Row 1:
|
||
──────
|
||
cluster: test_shard_localhost
|
||
shard_num: 1
|
||
shard_weight: 1
|
||
replica_num: 1
|
||
host_name: localhost
|
||
host_address: 127.0.0.1
|
||
port: 9000
|
||
is_local: 1
|
||
user: default
|
||
default_database:
|
||
errors_count: 0
|
||
estimated_recovery_time: 0
|
||
```
|
||
|
||
## SHOW SETTINGS
|
||
|
||
Returns a list of system settings and their values. Selects data from the [system.settings](../../operations/system-tables/settings.md) table.
|
||
|
||
**Syntax**
|
||
|
||
```sql
|
||
SHOW [CHANGED] SETTINGS LIKE|ILIKE <name>
|
||
```
|
||
|
||
**Clauses**
|
||
|
||
`LIKE|ILIKE` allow to specify a matching pattern for the setting name. It can contain globs such as `%` or `_`. `LIKE` clause is case-sensitive, `ILIKE` — case insensitive.
|
||
|
||
When the `CHANGED` clause is used, the query returns only settings changed from their default values.
|
||
|
||
**Examples**
|
||
|
||
Query with the `LIKE` clause:
|
||
|
||
```sql
|
||
SHOW SETTINGS LIKE 'send_timeout';
|
||
```
|
||
Result:
|
||
|
||
```text
|
||
┌─name─────────┬─type────┬─value─┐
|
||
│ send_timeout │ Seconds │ 300 │
|
||
└──────────────┴─────────┴───────┘
|
||
```
|
||
|
||
Query with the `ILIKE` clause:
|
||
|
||
```sql
|
||
SHOW SETTINGS ILIKE '%CONNECT_timeout%'
|
||
```
|
||
|
||
Result:
|
||
|
||
```text
|
||
┌─name────────────────────────────────────┬─type─────────┬─value─┐
|
||
│ connect_timeout │ Seconds │ 10 │
|
||
│ connect_timeout_with_failover_ms │ Milliseconds │ 50 │
|
||
│ connect_timeout_with_failover_secure_ms │ Milliseconds │ 100 │
|
||
└─────────────────────────────────────────┴──────────────┴───────┘
|
||
```
|
||
|
||
Query with the `CHANGED` clause:
|
||
|
||
```sql
|
||
SHOW CHANGED SETTINGS ILIKE '%MEMORY%'
|
||
```
|
||
|
||
Result:
|
||
|
||
```text
|
||
┌─name─────────────┬─type───┬─value───────┐
|
||
│ max_memory_usage │ UInt64 │ 10000000000 │
|
||
└──────────────────┴────────┴─────────────┘
|
||
```
|
||
|
||
## SHOW FILESYSTEM CACHES
|
||
|
||
```sql
|
||
SHOW FILESYSTEM CACHES
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─Caches────┐
|
||
│ s3_cache │
|
||
└───────────┘
|
||
```
|
||
|
||
**See Also**
|
||
|
||
- [system.settings](../../operations/system-tables/settings.md) table
|