7170f3c534
* prefer relative links from root * wip * split aggregate function reference * split system tables
4.8 KiB
| toc_priority | toc_title |
|---|---|
| 38 | SHOW |
SHOW Queries
SHOW CREATE TABLE
SHOW CREATE [TEMPORARY] [TABLE|DICTIONARY] [db.]table [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.
SHOW DATABASES
SHOW DATABASES [INTO OUTFILE filename] [FORMAT format]
Prints a list of all databases.
This query is identical to SELECT name FROM system.databases [INTO OUTFILE filename] [FORMAT format].
SHOW PROCESSLIST
SHOW PROCESSLIST [INTO OUTFILE filename] [FORMAT format]
Outputs the content of the system.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):
$ watch -n1 "clickhouse-client --query='SHOW PROCESSLIST'"
SHOW TABLES
Displays a list of tables.
SHOW [TEMPORARY] TABLES [{FROM | IN} <db>] [LIKE '<pattern>' | WHERE expr] [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.
You can get the same results as the SHOW TABLES query in the following way:
SELECT name FROM system.tables 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 co.
SHOW TABLES FROM system LIKE '%co%' LIMIT 2
┌─name───────────────────────────┐
│ aggregate_function_combinators │
│ collations │
└────────────────────────────────┘
SHOW DICTIONARIES
Displays a list of external dictionaries.
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:
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.
SHOW DICTIONARIES FROM db LIKE '%reg%' LIMIT 2
┌─name─────────┐
│ regions │
│ region_names │
└──────────────┘
SHOW GRANTS
Shows privileges for a user.
Syntax
SHOW GRANTS [FOR user]
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.
SHOW CREATE USER doesn’t output user passwords.
Syntax
SHOW CREATE USER [name | CURRENT_USER]
SHOW CREATE ROLE
Shows parameters that were used at a role creation.
Syntax
SHOW CREATE ROLE name
SHOW CREATE ROW POLICY
Shows parameters that were used at a row policy creation.
Syntax
SHOW CREATE [ROW] POLICY name ON [database.]table
SHOW CREATE QUOTA
Shows parameters that were used at a quota creation.
Syntax
SHOW CREATE QUOTA [name | CURRENT]
SHOW CREATE SETTINGS PROFILE
Shows parameters that were used at a settings profile creation.
Syntax
SHOW CREATE [SETTINGS] PROFILE name