[英]SQL Server does not rollback trigger transaction to savepoint
我在嘗試根據自己的觀點觸發交易時遇到問題。 這是我的DDL設置:
CREATE TABLE entity1 (
id INT NOT NULL IDENTITY PRIMARY KEY,
attr1 INT NOT NULL,
attr2 INT NOT NULL
);
GO
CREATE TABLE entity2 (
entity1_id INT NOT NULL FOREIGN KEY REFERENCES entity1(id),
attr3 INT NOT NULL,
attr4 INT NOT NULL
);
GO
CREATE VIEW my_view AS
SELECT attr1, attr2, attr3, attr4
FROM entity1 AS e1
INNER JOIN entity2 AS e2
ON e1.id = e2.entity1_id;
GO
CREATE TRIGGER tg_my_view_ins ON my_view
INSTEAD OF INSERT AS
BEGIN
BEGIN TRY
SAVE TRANSACTION here; -- checkpoint
INSERT INTO entity1 (attr1, attr2)
SELECT attr1, attr2 FROM inserted;
INSERT INTO entity2 (entity1_id, attr3, attr4)
SELECT SCOPE_IDENTITY(), attr3, attr4 FROM inserted;
END TRY
BEGIN CATCH
ROLLBACK TRANSACTION here; -- rollback to checkpoint in case on an error
END CATCH
END
GO
如您所見,我在觸發器中創建了一個保存點,並在出現任何錯誤的情況下進行了回滾(我假設約束錯誤也由TRY / CATCH塊處理)。 問題是,當我在事務內執行錯誤的插入操作時,觸發器錯誤處理塊不會回滾:
BEGIN TRY
BEGIN TRANSACTION;
-- successful insert
INSERT INTO my_view (attr1, attr2, attr3, attr4) VALUES (1,2,3,4);
SELECT * FROM entity1; -- one entity
-- i wrap the bad insert into try/catch so the error is discarded,
-- but still rolled back
BEGIN TRY
INSERT INTO my_view (attr1, attr2, attr3) VALUES (3,2,1);
END TRY
BEGIN CATCH
END CATCH;
SELECT * FROM entity1; -- should only have one entity, but has two
ROLLBACK; -- discard the whole transaction
END TRY
BEGIN CATCH
ROLLBACK; -- discard the whole transaction in case of any errors
END CATCH;
我似乎無法以發生錯誤時不會創建孤立記錄的方式來設置觸發器。 我嘗試在觸發器中使用BEGIN TRANSACTION here
和COMMIT TRANSACTION here
而不是SAVE TRANSACTION here
,但是沒有運氣。 處理觸發器中的約束錯誤的正確方法是什么?
如果可能的話,我想保持執行設置的狀態。 我創建並回滾事務以進行測試。 我將錯誤的插入文件包裝到try / catch塊中,以丟棄我知道應該發生的錯誤。
通過將錯誤日志記錄添加到catch
塊中,可以弄清這種看似混亂的行為。 測試代碼的以下修改添加了錯誤日志記錄(以及其他一些改進),該錯誤記錄顯示了該過程中實際發生的情況:
begin try
begin transaction;
INSERT INTO dbo.my_view (attr1, attr2, attr3, attr4) VALUES (1,2,3,4);
SELECT * FROM dbo.entity1;
BEGIN TRY
INSERT INTO dbo.my_view (attr1, attr2, attr3) VALUES (3,2,1);
END TRY
BEGIN CATCH
-- Logging - inner CATCH
select 'Inner', @@trancount, error_number(), error_message(), error_procedure(), error_line();
END CATCH;
select * from dbo.entity1;
rollback;
end try
begin catch
-- Logging - outer CATCH
select 'Outer', @@trancount, error_number(), error_message(), error_procedure(), error_line();
-- Conditional rollback, because some errors always terminate the transaction
if @@trancount > 0
rollback;
end catch;
如果您在完整觸發條件的情況下運行此代碼,則會看到內部CATCH
捕獲到錯誤:
3931
當前事務無法提交,也不能回滾到保存點。 回滾整個事務。
通過錯誤號搜索導致該帖子出現類似問題。 Rutzky在他的回答中表明,此行為的罪魁禍首是XACT_ABORT
會話選項,該選項顯然已默認設置為ON
。 如果您打算采用基於觸發器的體系結構,那么在觸發器內部關閉此選項將有幫助:
create or alter trigger dbo.tg_my_view_ins
on dbo.my_view
instead of insert as
-- Implicitly set to ON in triggers by default; makes error handling impossible
set xact_abort off;
begin try
save transaction here;
INSERT INTO dbo.entity1 (attr1, attr2)
SELECT attr1, attr2 FROM inserted;
INSERT INTO dbo.entity2 (entity1_id, attr3, attr4)
SELECT e.id, attr3, attr4
FROM inserted i
-- The actual JOIN condidions should reference a natural key in the master table.
-- This is just an example.
inner join dbo.entity1 e on e.attr1 = i.attr1 and e.attr2 = i.attr2;
end try
begin catch
if @@trancount > 0
rollback transaction here;
end catch;
return;
GO
(再次,我已更正了您的代碼的其他幾個問題。)
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