Skip to content

Latest commit

 

History

History
268 lines (205 loc) · 9.13 KB

sql-statement-create-table.md

File metadata and controls

268 lines (205 loc) · 9.13 KB
Raw
title summary aliases
CREATE TABLE | TiDB SQL Statement Reference
An overview of the usage of CREATE TABLE for the TiDB database.
/docs/dev/sql-statements/sql-statement-create-table/
/docs/dev/reference/sql/statements/create-table/

CREATE TABLE

This statement creates a new table in the currently selected database. It behaves similarly to the CREATE TABLE statement in MySQL.

Synopsis

CreateTableStmt ::=
    'CREATE' OptTemporary 'TABLE' IfNotExists TableName ( TableElementListOpt CreateTableOptionListOpt PartitionOpt DuplicateOpt AsOpt CreateTableSelectOpt | LikeTableWithOrWithoutParen ) OnCommitOpt

OptTemporary ::=
    ( 'TEMPORARY' | ('GLOBAL' 'TEMPORARY') )?

IfNotExists ::=
    ('IF' 'NOT' 'EXISTS')?

TableName ::=
    Identifier ('.' Identifier)?

TableElementListOpt ::=
    ( '(' TableElementList ')' )?

TableElementList ::=
    TableElement ( ',' TableElement )*

TableElement ::=
    ColumnDef
|   Constraint

ColumnDef ::=
    ColumnName ( Type | 'SERIAL' ) ColumnOptionListOpt

ColumnOptionListOpt ::=
    ColumnOption*

ColumnOptionList ::=
    ColumnOption*

ColumnOption ::=
    'NOT'? 'NULL'
|   'AUTO_INCREMENT'
|   PrimaryOpt 'KEY'
|   'UNIQUE' 'KEY'?
|   'DEFAULT' DefaultValueExpr
|   'SERIAL' 'DEFAULT' 'VALUE'
|   'ON' 'UPDATE' NowSymOptionFraction
|   'COMMENT' stringLit
|   ConstraintKeywordOpt 'CHECK' '(' Expression ')' EnforcedOrNotOrNotNullOpt
|   GeneratedAlways 'AS' '(' Expression ')' VirtualOrStored
|   ReferDef
|   'COLLATE' CollationName
|   'COLUMN_FORMAT' ColumnFormat
|   'STORAGE' StorageMedia
|   'AUTO_RANDOM' OptFieldLen

Constraint ::=
    IndexDef
|   ForeignKeyDef

IndexDef ::=
    ( 'INDEX' | 'KEY' ) IndexName? '(' KeyPartList ')' IndexOption?

KeyPartList ::=
    KeyPart ( ',' KeyPart )*

KeyPart ::=
    ColumnName ( '(' Length ')')? ( 'ASC' | 'DESC' )?
|   '(' Expression ')' ( 'ASC' | 'DESC' )?

IndexOption ::=
    'COMMENT' String
|   ( 'VISIBLE' | 'INVISIBLE' )
|   ('USING' | 'TYPE') ('BTREE' | 'RTREE' | 'HASH')

ForeignKeyDef
         ::= ( 'CONSTRAINT' Identifier )? 'FOREIGN' 'KEY'
             Identifier? '(' ColumnName ( ',' ColumnName )* ')'
             'REFERENCES' TableName '(' ColumnName ( ',' ColumnName )* ')'
             ( 'ON' 'DELETE' ReferenceOption )?
             ( 'ON' 'UPDATE' ReferenceOption )?

ReferenceOption
         ::= 'RESTRICT'
           | 'CASCADE'
           | 'SET' 'NULL'
           | 'SET' 'DEFAULT'
           | 'NO' 'ACTION'

CreateTableOptionListOpt ::=
    TableOptionList?

PartitionOpt ::=
    ( 'PARTITION' 'BY' PartitionMethod PartitionNumOpt SubPartitionOpt PartitionDefinitionListOpt )?

DuplicateOpt ::=
    ( 'IGNORE' | 'REPLACE' )?

TableOptionList ::=
    TableOption ( ','? TableOption )*

TableOption ::=
    PartDefOption
|   DefaultKwdOpt ( CharsetKw EqOpt CharsetName | 'COLLATE' EqOpt CollationName )
|   ( 'AUTO_INCREMENT' | 'AUTO_ID_CACHE' | 'AUTO_RANDOM_BASE' | 'AVG_ROW_LENGTH' | 'CHECKSUM' | 'TABLE_CHECKSUM' | 'KEY_BLOCK_SIZE' | 'DELAY_KEY_WRITE' | 'SHARD_ROW_ID_BITS' | 'PRE_SPLIT_REGIONS' ) EqOpt LengthNum
|   ( 'CONNECTION' | 'PASSWORD' | 'COMPRESSION' ) EqOpt stringLit
|   RowFormat
|   ( 'STATS_PERSISTENT' | 'PACK_KEYS' ) EqOpt StatsPersistentVal
|   ( 'STATS_AUTO_RECALC' | 'STATS_SAMPLE_PAGES' ) EqOpt ( LengthNum | 'DEFAULT' )
|   'STORAGE' ( 'MEMORY' | 'DISK' )
|   'SECONDARY_ENGINE' EqOpt ( 'NULL' | StringName )
|   'UNION' EqOpt '(' TableNameListOpt ')'
|   'ENCRYPTION' EqOpt EncryptionOpt
|    'TTL' EqOpt TimeColumnName '+' 'INTERVAL' Expression TimeUnit (TTLEnable EqOpt ( 'ON' | 'OFF' ))? (TTLJobInterval EqOpt stringLit)?
|   PlacementPolicyOption

OnCommitOpt ::=
    ('ON' 'COMMIT' 'DELETE' 'ROWS')?

PlacementPolicyOption ::=
    "PLACEMENT" "POLICY" EqOpt PolicyName
|   "PLACEMENT" "POLICY" (EqOpt | "SET") "DEFAULT"

The following table_options are supported. Other options such as AVG_ROW_LENGTH, CHECKSUM, COMPRESSION, CONNECTION, DELAY_KEY_WRITE, ENGINE, KEY_BLOCK_SIZE, MAX_ROWS, MIN_ROWS, ROW_FORMAT and STATS_PERSISTENT are parsed but ignored.

Options Description Example
AUTO_INCREMENT The initial value of the increment field AUTO_INCREMENT = 5
SHARD_ROW_ID_BITS To set the number of bits for the implicit _tidb_rowid shards SHARD_ROW_ID_BITS = 4
PRE_SPLIT_REGIONS To pre-split 2^(PRE_SPLIT_REGIONS) Regions when creating a table PRE_SPLIT_REGIONS = 4
AUTO_ID_CACHE To set the auto ID cache size in a TiDB instance. By default, TiDB automatically changes this size according to allocation speed of auto ID AUTO_ID_CACHE = 200
AUTO_RANDOM_BASE To set the initial incremental part value of auto_random. This option can be considered as a part of the internal interface. Users can ignore this parameter AUTO_RANDOM_BASE = 0
CHARACTER SET To specify the character set for the table CHARACTER SET = 'utf8mb4'
COMMENT The comment information COMMENT = 'comment info'

Note:

The split-table configuration option is enabled by default. When it is enabled, a separate Region is created for each newly created table. For details, see TiDB configuration file.

Note:

TiDB creates a separate Region for each newly created table.

Examples

Creating a simple table and inserting one row:

{{< copyable "sql" >}}

CREATE TABLE t1 (a int);
DESC t1;
SHOW CREATE TABLE t1\G
INSERT INTO t1 (a) VALUES (1);
SELECT * FROM t1;
mysql> drop table if exists t1;
Query OK, 0 rows affected (0.23 sec)

mysql> CREATE TABLE t1 (a int);
Query OK, 0 rows affected (0.09 sec)

mysql> DESC t1;
+-------+---------+------+------+---------+-------+
| Field | Type    | Null | Key  | Default | Extra |
+-------+---------+------+------+---------+-------+
| a     | int(11) | YES  |      | NULL    |       |
+-------+---------+------+------+---------+-------+
1 row in set (0.00 sec)

mysql> SHOW CREATE TABLE t1\G
*************************** 1. row ***************************
       Table: t1
Create Table: CREATE TABLE `t1` (
  `a` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin
1 row in set (0.00 sec)

mysql> INSERT INTO t1 (a) VALUES (1);
Query OK, 1 row affected (0.03 sec)

mysql> SELECT * FROM t1;
+------+
| a    |
+------+
|    1 |
+------+
1 row in set (0.00 sec)

Dropping a table if it exists, and conditionally creating a table if it does not exist:

{{< copyable "sql" >}}

DROP TABLE IF EXISTS t1;
CREATE TABLE IF NOT EXISTS t1 (
 id BIGINT NOT NULL PRIMARY KEY auto_increment,
 b VARCHAR(200) NOT NULL
);
DESC t1;
mysql> DROP TABLE IF EXISTS t1;
Query OK, 0 rows affected (0.22 sec)

mysql> CREATE TABLE IF NOT EXISTS t1 (
         id BIGINT NOT NULL PRIMARY KEY auto_increment,
         b VARCHAR(200) NOT NULL
        );
Query OK, 0 rows affected (0.08 sec)

mysql> DESC t1;
+-------+--------------+------+------+---------+----------------+
| Field | Type         | Null | Key  | Default | Extra          |
+-------+--------------+------+------+---------+----------------+
| id    | bigint(20)   | NO   | PRI  | NULL    | auto_increment |
| b     | varchar(200) | NO   |      | NULL    |                |
+-------+--------------+------+------+---------+----------------+
2 rows in set (0.00 sec)

MySQL compatibility

  • All of the data types except spatial types are supported.
  • TiDB accepts index types such as HASH, BTREE and RTREE in syntax for compatibility with MySQL, but ignores them.
  • TiDB supports parsing the FULLTEXT syntax but does not support using the FULLTEXT indexes.
  • For compatibility, the index_col_name attribute supports the length option with a maximum length limit of 3072 bytes by default. The length limit can be changed through the max-index-length configuration option. For details, see TiDB configuration file.
  • For compatibility, the index_col_name attribute supports the length option with a maximum length limit of 3072 bytes.
  • The [ASC | DESC] in index_col_name is currently parsed but ignored (MySQL 5.7 compatible behavior).
  • The COMMENT attribute does not support the WITH PARSER option.
  • TiDB supports 1017 columns in a single table by default and 4096 columns at most. The corresponding number limit in InnoDB is 1017 columns, and the hard limit in MySQL is 4096 columns. For details, see TiDB Limitations.
  • TiDB supports HASH, RANGE, LIST, and KEY partitioning types. For an unsupported partition type, TiDB returns Warning: Unsupported partition type %s, treat as normal table, where %s is the specific unsupported partition type.

See also