Why can I insert into talbe "DUAL"?
393562Aug 28 2003 — edited Aug 28 2003Hello All,
I have a simple question about system table "DUAL"
.................................................................
SQL> SELECT * FROM DUAL;
DUMMY
-----
X
SQL> INSERT INTO DUAL VALUES ('Y');
1 row inserted
SQL> SELECT * FROM DUAL;
DUMMY
-----
X
Y
SQL> SELECT SYSDATE FROM DUAL;
SYSDATE
-----------
2003-08-28
2003-08-28
SQL> DELETE FROM DUAL;
1 row deleted
SQL> SELECT SYSDATE FROM DUAL;
SYSDATE
-----------
.................................................................
If DUAL exists 2 records or 0 record,it maybe occur some problem?
So I want to ask why can we insert into DUAL.