无法使用临时表查看不受 UPDATE 影响的行

Question

I need to update some 600+ rows of customer data, using a query I've generated from Excel. I'm generating my update query using data that is more recent than the data we have in our test environment - so I want to view the rows that were not updated when I finish executing within the test environment.

I am trying to achieve this with IF @@ROWCOUNT < 1 .

Consider the following update query:

CREATE TABLE #not_updated (
  NOT_UPDATED VARCHAR(30)
);

UPDATE TABLE1 SET COL1 = 'text1A' WHERE COL2 LIKE 'text1B'; IF @@ROWCOUNT < 1 INSERT INTO #not_updated SELECT 'text1B'
UPDATE TABLE1 SET COL1 = 'text2A' WHERE COL2 LIKE 'text2B'; IF @@ROWCOUNT < 1 INSERT INTO #not_updated SELECT 'text2B'
--            |
--            V
-- 600+ MORE INSERTS...

SELECT * FROM #not_updated

DROP TABLE #temp

However, when I run the query, SELECT * FROM #not_updated it does not return any rows - even though I can see in the "Messages" tab 0 rows affected for some of the entries.

If I change my code to IF @@ROWCOUNT = 1 , my select will return that entry. Any ideas on what I'm doing wrong? Or if there is an easier way to achieve this?

Answer 1

I'm not sure about the reliability of @@ROWCOUNT when UPDATE fails (entry does not exist). For now, I'm using the following workaround:

UPDATE TABLE1 SET COL1 = 'text1A' WHERE COL2 LIKE 'text1B'; IF (SELECT COUNT(*) TABLE1 WHERE COL2 LIKE 'text1B') < 1 INSERT INTO #not_updated SELECT 'text1B'