问题
Here is the scenario, I am writing a procedure which performs DML(insert,delete) operations on multiple tables. In case of exception I need to rollback data from most of the tables except one.
Example:
Procedure{
1 Insert into table1
2 Delete from table2
3 Insert into Table3
4 Insert into table4
Commit;
Exception
Rollback;
}
If there is any exception in 4th Insert, I need to rollback all previous transaction except 3rd one. I know, commit/rollback doesn't work like that. But maybe is there way while creating table3, I can set some parameter so that every INSERT statement on table3 will be auto commited.
回答1:
It's possible using an Autonomous Transaction.
CREATE TABLE t1 (x INTEGER PRIMARY KEY);
CREATE TABLE t2 (x INTEGER);
CREATE TABLE t3 (x INTEGER);
CREATE TABLE t4 (x INTEGER REFERENCES t1(x));
Then run this anononymous PL/SQL. Look carefully, the local procedure upd_table_3 isn't run when it's declared. It's run when called within the main BEGIN block:
DECLARE
PROCEDURE upd_table_3 IS
PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
INSERT INTO t3 VALUES (3);
COMMIT;
END;
BEGIN
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
upd_table_3;
INSERT INTO t4 VALUES (4);
COMMIT;
END;
/
The procedure should fail intentionally on the 4th insert with ORA-02291. I made it this way. Then
ROLLBACK;
All the tables should be rolled back except t3, which we did the insert in an autonomous transaction.
SELECT * FROM t1;
no rows selected
SELECT * FROM t2;
no rows selected
SELECT * FROM t3;
X
----------
3
SELECT * FROM t4;
no rows selected
回答2:
From your post explanation what I understood is #3 insert has no dependency on other insert and you anyways want to commit it. In that case you can have them in different transaction block like.
begin transaction
1 Insert into table1
2 Delete from table2
4 Insert into table4
Commit;
Exception
Rollback;
Second Part
begin transaction
3 Insert into Table3
commit
On Exception
Rollback;
(OR) using a save point like below, that way #3 insert will not be rolled back.
BEGIN
SAVEPOINT startpoint;
3 Insert into Table3;
SAVEPOINT startpoint2;
1 Insert into table1;
2 Delete from table2;
4 Insert into table4;
EXCEPTION
WHEN SOMETHING THEN
ROLLBACK TO startpoint2;
RAISE;
END;
PS: Syntax may not be proper; So consult the documentation. SAVEPOINT idea taken from BEGIN - END block atomic transactions in PL/SQL
回答3:
There is nothing to do. Take your script:
1 Insert into table1
2 Delete from table2
3 Insert into Table3
4 Insert into table4
Commit;
Assume you get an exception in statement 4, then statement 4 is actually not executed thus it does not make sense to rollback statement 4. A simple COMMIT will commit only statements 1,2,3 in this case.
However, it looks different when you get an exception at statement 3, for example (while statement 4 runs fine). Do you like to rollback to statement 2 in this case, i.e. rollback also statement 4? Then you have to work with SAVEPOINTS as mentioned in the other answers.
来源：https://stackoverflow.com/questions/24419183/create-oracle-table-with-auto-commit-on