ORA-01400: cannot insert NULL into (string)

Cause:  An attempt was made to insert a NULL into the column "USER"."TABLE"."COLUMN".

For Example,

I created a table as below

CREATE TABLE DEPT

(

DEPT_NO      NUMBER NOT NULL,

DEPT_NAME    VARCHAR2(240) NOT NULL);

When i tried to execute this statement, i got the following error as shown.

INSERT INTO DEPT

(DEPT_NO)

VALUES

(

101

)

Action:

Retry the operation with a value other than NULL.

INSERT INTO DEPT

(DEPT_NO)

VALUES

(

101,

'IT'

)