SQL>
SQL> CREATE TABLE MyTable (
2 num_col NUMBER,
3 char_col VARCHAR2(60)
4 );
Table created.
SQL>
SQL>
SQL> CREATE OR REPLACE TRIGGER OnlyPositive
2 BEFORE INSERT OR UPDATE OF num_col
3 ON MyTable
4 FOR EACH ROW
5 BEGIN
6 IF :new.num_col < 0 THEN
7 RAISE_APPLICATION_ERROR(-20100, 'Please insert a positive value');
8 END IF;
9 END OnlyPositive;
10 /
Trigger created.
SQL>
SQL> INSERT INTO MyTable (num_col, char_col)
2 VALUES (1, 'This is row 1');
1 row created.
SQL>
SQL> INSERT INTO MyTable (num_col, char_col)
2 VALUES (-1, 'This is row -1');
INSERT INTO MyTable (num_col, char_col)
*
ERROR at line 1:
ORA-20100: Please insert a positive value
ORA-06512: at "RNTSOFT.ONLYPOSITIVE", line 3
ORA-04088: error during execution of trigger 'RNTSOFT.ONLYPOSITIVE'
SQL>
SQL> drop table MyTable;
Table dropped.
SQL>
SQL>