Group Sequence、Time-based Sequence或Simple Sequence
创建Group Sequence、Time-based Sequence或Simple Sequence作为自增列的表语法如下:
CREATE TABLE <name> ( <column> ... AUTO_INCREMENT [ BY GROUP | SIMPLE | TIME ], <column definition>, ... ) ... AUTO_INCREMENT=<start value>
说明 如果指定了BY TIME
,即Time-based Sequence,则该列类型必须为BIGINT。
单元化Group Sequence
创建单元化Group Sequence的表语法如下:
CREATE TABLE <name> ( <column> ... AUTO_INCREMENT [ BY GROUP ] [ UNIT COUNT <numeric value> INDEX <numeric value> ], <column definition>, ... ) ... AUTO_INCREMENT=<start value>
示例
示例一:默认创建一张使用Group Sequence作为自增列的表。
请在命令行输入如下代码:
mysql> CREATE TABLE tab1 ( col1 BIGINT NOT NULL AUTO_INCREMENT, col2 VARCHAR(16), PRIMARY KEY(col1) ) DBPARTITION BY HASH(col1);
示例二:创建3张同名的、使用相同单元数量和不同单元索引的单元化Group Sequence作为自增列的表,分别用于3个不同的实例或库。
- 实例1/库1请在命令行输入如下代码:
mysql> CREATE TABLE tab2 ( col1 BIGINT NOT NULL AUTO_INCREMENT UNIT COUNT 3 INDEX 0, col2 VARCHAR(16), PRIMARY KEY(col1) ) DBPARTITION BY HASH(col1);
- 实例2/库2请在命令行输入如下代码:
mysql> CREATE TABLE tab2 ( col1 BIGINT NOT NULL AUTO_INCREMENT UNIT COUNT 3 INDEX 1, col2 VARCHAR(16), PRIMARY KEY(col1) ) DBPARTITION BY HASH(col1);
- 实例3/库3请在命令行输入如下代码:
mysql> CREATE TABLE tab2 ( col1 BIGINT NOT NULL AUTO_INCREMENT UNIT COUNT 3 INDEX 2, col2 VARCHAR(16), PRIMARY KEY(col1) ) DBPARTITION BY HASH(col1);
示例三:创建一张使用Time-based Sequence作为自增列的表。
请在命令行输入如下代码:
mysql> CREATE TABLE tab3 ( col1 BIGINT NOT NULL AUTO_INCREMENT BY TIME, col2 VARCHAR(16), PRIMARY KEY(col1) ) DBPARTITION BY HASH(col1);
示例四:创建一张使用Simple Sequence作为自增列的表。
请在命令行输入如下代码:
mysql> CREATE TABLE tab4 ( col1 BIGINT NOT NULL AUTO_INCREMENT BY SIMPLE, col2 VARCHAR(16), PRIMARY KEY(col1) ) DBPARTITION BY HASH(col1);