- In order to add new column to a table:
ALTER TABLE tbl_emp ADD col_name VARCHAR2(160) NOT NULL ;
2. In order to add multiple new columns at once to a table:
ALTER TABLE tbl_emp ADD
(
col_name1 VARCHAR2(160) NOT NULL,
col_name 2 VARCHAR2(30) NOT NULL
);
3. In Order to rename a table name:
ALTER TABLE tbl_old_name RENAME TO tbl_new_name;
4. In Order to Modify a column properties in a table:
ALTER TABLE tbl_name MODIFY
(
col_name1 VARCHAR2(25) NOT NULL,
col_name2 number,
col_name3 VARCHAR2(100)
);
5. In Order to Drop a column from a table:
ALTER TABLE tbl_name DROP COLUMN col_name1;
6. In Order to Rename a column in a table:
ALTER TABLE tbl_name RENAME COLUMN col_old_name to col_new_name;
7. In Order to Change the password of a user:
ALTER USER myuser IDENTIFIED BY new_password;
8. In order to Lock a User Account:
ALTER USER myuser ACCOUNT LOCK;
9. In order to Unlock a User Account:
ALTER USER myuser ACCOUNT UNLOCK;
10. In order to Expire the password of a User:
ALTER USER myuser PASSWORD EXPIRE;
