Unique Key Syntax

hi

There is a table with rows , with one column as NOT NULL constratint.
I want to add unique key constraint in that column

can u please provide me syntax.

This should help

Code:

---

ALTER TABLE table_name
 ADD CONSTRAINT constraint_name
 UNIQUE (column_name)

---

Regards

Hi,
use:
ALTER TABLE
ADD CONSTRAINT
UNIQUE ();

example:
ALTER TABLE EMP ADD CONSTRAINT EMP_NO_UNQ UNIQUE (EMPNO);

Cheers,
R.

hi all i am getting this error vcan any one help me out.

ALTER TABLE PRONTO_WISP ADD CONSTRAINT WPNAME_UN UNique(WISP_NAME)
*
ERROR at line 1:
ORA-02299: cannot validate (WINTER02.WPNAME_UN) - duplicate keys found

You are trying to create UNIQUE constraint on column WISP_NAME, but it has duplicate contents.

Code:

---

SELECT * FROM pronto_wisp
WHERE ROWID NOT IN
( SELECT MIN(ROWID) FROM pronto_wisp GROUP BY wisp_name)

---

Above sql stmt will give you duplicate records for WISP_NAME. You need to delete duplicate entries prior to creating constraint.

Sameer