SQL-仅在所有记录匹配时更新字段

Question

I'm fairly new to SQL and have a question about an UPDATE query. I'm using SQL server 2008 R2. I have written the following SELECT query:

SELECT res.labresultcat_id, res.patient_id, lab.test_performed,
lab.result_status, lab.result_value, lab.abnormal_flag, res.recorded_on, 
res.cat_test_name, res.results_to, usr.last_name, res.result_viewed
FROM dbo.med_labresultcat res
INNER JOIN dbo.med_labresult lab
ON res.labresultcat_id = lab.labresultcat_id
LEFT JOIN dbo.res_user usr
ON res.results_to = usr.resource_id
WHERE lab.result_status = 'F' AND usr.last_name = 'Smith'
AND res.result_viewed is NULL

The results of which look something like this:

patient_id    result_id   test_performed     abnormal_flag    recorded_on    results_to    
0001          0045        ABC                N                4/1/2013       14            
0001          0045        CBS                A                4/1/2013       14           
0002          0061        NBC                N                4/3/2013       13            
0002          0061        MST                N                4/3/2013       13
0003          0090        ABC                H                4/20/2013      10
0003          0090        MST                N                4/20/2013      10

So, I've written the following UPDATE query:

;WITH lab AS  (SELECT res.labresultcat_id, res.patient_id, lab.test_performed,
lab.result_status, lab.result_value, lab.abnormal_flag, res.recorded_on, 
res.cat_test_name, res.results_to, usr.last_name, res.result_viewed
FROM dbo.med_labresultcat res
INNER JOIN dbo.med_labresult lab
ON res.labresultcat_id = lab.labresultcat_id
LEFT JOIN dbo.res_user usr
ON res.results_to = usr.resource_id
WHERE lab.result_status = 'F' AND usr.last_name = 'Smith'
AND res.result_viewed is NULL AND (abnormal_flag = 'N' OR abnormal_flag is NULL))
UPDATE lab SET results_to = '184'

The above query does updated the person assigned to the lab result. However, I need to only update the results_to field if all the results with the same result_id are 'N' or NULL.

Any help if greatly appreciated. Thank you!

Answer 1

只需在更新语句后附加一个where子句，然后在该where语句中执行匹配子句。