USING TCL
USING COMMIT
This will be used to save the work.
Commit is of two types.
Ø Implicit
Ø Explicit
a) IMPLICIT
This will be issued by oracle internally in
two situations.
Ø When any DDL operation is
performed.
Ø When you are exiting from
SQL * PLUS.
b) EXPLICIT
This will be issued by
the user.
Syntax:
Commit or commit
work;
* When ever you committed then the
transaction was completed.
USING ROLLBACK
This will undo the operation.
This will be applied in two methods.
Ø Upto previous commit
Ø Upto previous rollback
Syntax:
Roll or roll work;
Or
Rollback or rollback work;
* While process is going on, if suddenly power goes then oracle
will rollback the transaction.
USING SAVEPOINT
You can use savepoints to rollback portions of your current set of
transactions.
Syntax:
Savepoint <savepoint_name>;
Ex:
SQL> savepoint s1;
SQL> insert into student
values(1, ‘a’, 100);
SQL> savepoint s2;
SQL> insert into student values(2, ‘b’, 200);
SQL> savepoint s3;
SQL> insert into student values(3, ‘c’, 300);
SQL> savepoint s4;
SQL> insert into student values(4, ‘d’, 400);
Before rollback
SQL> select * from student;
NO NAME MARKS
---
------- ----------
1 a 100
2 b 200
3 c 300
4 d 400
SQL> rollback to savepoint s3;
Or
SQL> rollback to s3;
This will rollback last
two records.
SQL> select * from student;
NO NAME MARKS
---
------- ----------
1 a 100
2 b 200
No comments:
Post a Comment