2.添加字段:ALTER TABLE 表名 ADD 字段名 数据类型[属性]; 3.修改字段:ALTER TABLE 表名 CHANGE 原字段名 新字段名 数据类型[属性]; 4.删除字段:ALTER TABLE 表名 DROP 字段名; 2.添加主键 1.语法:ALTER TABLE 表名 ADD CONSTRAINT 主键名 PRIMARY KEY 表名(主键字段); 3.添加外键 1.语法:ALTER TABL...
Here,table_nameis the name of the table to which you want to add the primary key.column1, column2, ...are the names of the columns that you want to use as the primary key. You can specify multiple columns separated by commas to create a composite primary key. Example: Adding a Pri...
ALTER TABLE modifies a table definition by altering, adding, or dropping columns and constraints. ALTER TABLE also reassigns and rebuilds partitions, or disables and enables constraints and triggers.
obclient [test]> alter table t1 add primary key(id); ERROR 1235 (0A000): Not supported feature or function # 参考OB手册,用modify和change语法也失败 obclient [test]> alter table t1 modify id int primary key; ERROR 1235 (0A000): Not supported feature or function obclient [test]> alter ...
Similar to creating index, when we runALTER TABLE ADD PRIMARY KEY, we should: 1. Create a new table with the PK. 2. Any writes to old table should go to both old and new tables. 3. Backfill new table with entries from old table. 4. Switch all writes to only write to new tabl...
An action can be anything such as adding a new column, adding primary key, renaming table, etc. The ALTER TABLE statement allows you to apply multiple actions in a single ALTER TABLE statement, each action is separated by a comma (,).Let’s create a new table for practicing the ALTER ...
主键不能为空，你定义的主键类型可以为空
To alter an existing table: First, you specify the table name that you want to change after theALTER TABLEkeywords. Second, you list a set of actions that you want to apply to the table. An action can be anything such as adding a new column, adding primary key, renaming table, etc....
Jira Link: DB-2164 Hello, I am trying to migrate the Postgres database to YSQL DB. Created dump of postgres db using pg_dump and trying to restore in YSQL DB using pg_restore. pg_dump creates the create table script without any constrain...
(DFG2)Alter Table - ADD PRIMARY KEY Table Identification: Owner . . . . . . .KPS8810_LONG+ Name . . . . . . .VACT+ Primary Key: Column name 1 . . .2 . . .3 . . .4 . . .5 . . .6 . . .7 . . .8 . . .Command ===>F1=Help F2=Split F3=Exit F4=Expand F7...