In MySQL mode of OceanBase Database, you can add a primary key, change a primary key, and drop a primary key.
Add a primary key
Syntax:
ALTER TABLE table_name ADD PRIMARY KEY (column_name);
Sample code:
obclient> CREATE TABLE tbl1(c1 INT,c2 VARCHAR(50));
Query OK, 0 rows affected
obclient> ALTER TABLE tbl1 ADD PRIMARY KEY(c1);
Query OK, 0 rows affected
Change a primary key
Syntax:
ALTER TABLE table_name DROP PRIMARY KEY,ADD PRIMARY KEY (column_name_list);
Sample code:
obclient> ALTER TABLE tbl1 DROP PRIMARY KEY,ADD PRIMARY KEY(c2);
Query OK, 0 rows affected
Drop a primary key
Syntax:
ALTER TABLE table_name DROP PRIMARY KEY;
Sample code:
obclient> ALTER TABLE tbl1 DROP PRIMARY KEY;
Query OK, 0 rows affected