SQL Server Error 8115 - CONVERT varchar to datetime

The following SELECT statement works fine:
SELECT * FROM MyTable WHERE ISDATE(MyStringField) = 1 AND CONVERT(datetime, MyStringField) < GETDATE()

However, the following UPDATE fails:
UPDATE MyTable SET StatusField = 'Overdue' WHERE ISDATE(MyStringField) = 1 AND CONVERT(datetime, MyStringField) < GETDATE()

The error message is:
Server: Msg 8115, Level 16, State 2, Line 1
Arithmetic overflow error converting expression to data type datetime.
The statement has been terminated.


Is there a way to figure out which row is causing this problem and can anyone suggest how I can modify my statement to fix this error?
FrenchJerichoAsked:
Who is Participating?
 
Scott PletcherConnect With a Mentor Senior DBACommented:
As far as changing the statement to make it work, I think this will do it:

UPDATE MyTable
SET StatusField = 'Overdue'
WHERE CASE WHEN ISDATE(MyStringField) = 1
           THEN CONVERT(datetime, MyStringField)
           ELSE GETDATE() END  < GETDATE()

0
 
Scott PletcherSenior DBACommented:
As far as determining which row is causing the problem, the following query should give you all rows that could potentially cause the problem.  I'm not sure how to nail it down to a specific one:

SELECT *
FROM MyTable
WHERE ISDATE(MyStringField) = 0
--AND MyStringField > ' '  --include this if desired to eliminate NULL and empty strings
0
 
FrenchJerichoAuthor Commented:
You suggestion works like a charm! Thanks.

However, I was checking for ISDATE(MyStringField) = 1 in my original query so I don't understand why it didn't work. Anybody can help me understand?
0
 
Scott PletcherSenior DBACommented:
I don't understand why it didn't work since it's connected by an AND condition:

"WHERE ISDATE(MyStringField) = 1 AND CONVERT(datetime, MyStringField) < GETDATE()"

Once SQL determines that the ISDATE is false, it should not even evaluate the CONVERT -- they both can't be true ("... AND ...") if the first one is not true.  Usually SQL optimizers are very good at recognizing these situations and exploiting them to do as little calcuation/retrieval as is absolutely necessary.

If the connector were "OR", it would have to evaluate both, and I could see the error occuring.
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.