Question

I am writing a utility, C#, to import a large CSV with about 80 columns into a SQL Server 2008 table.

The CSV needs manipulation before import e.g. merging some columns, converting dates etc. I am therefore constructing an INSERT INTO statement like so:

INSERT INTO table VALUES ('abc','blah',...)

My problem is that the table contains a column of type UNIQUEINDENTIFIER. It’s a problem because I would like to re-use an existing method which takes a collection of values and returns the string of values to pop directly into my INSERT INTO statement with apostrophes dealt with, injection attacks munged out etc.

Is there a way of generating a valid literal for a UNIQUEIDENTIFIER that I can pass to this method? I tried Guid.NewGuid.ToString(), which gives me a literal like so 'bfdb0297-2018-4555-ac12-88064944a671', but my query then errors with a data truncation exception. I also tried with the hyphens removed. I expected 32 hex characters to work.

I know that a parameterised query is the correct way to go but that would mean a significant re-work of existing code.

I’m pretty good with C# and bluff-worthy with SQL Server.

[EDIT]

I’ve done several things. First, wrote a query which updates that column with Guid.NewGuid at it works. Therefore, the truncation error is not from there. Checking the SQL Server reference leads me to believe that a truncation error is not returned from a bad value in an id column, rather it’s an invalid value error. I’ve also taken into account Aaron’s comment that significant work is not an excuse for not doing it right and have created a method to generate a parameterised query which is now working fine.

Many thanks to all responders.

Answer 1

Since this works fine:

DECLARE @x TABLE(y UNIQUEIDENTIFIER); 

INSERT @x SELECT 'bfdb0297-2018-4555-ac12-88064944a671';

And this fails with the generic error message that you’re currently getting:

DECLARE @x TABLE
(
  y UNIQUEIDENTIFIER,
  z CHAR(10)
); 

INSERT @x 
  SELECT 'bfdb0297-2018-4555-ac12-88064944a671',
         '0123456789A';

Result:

Msg 8152, Level 16, State 14, Line 7
String or binary data would
be truncated.
The statement has been terminated.

I have to question whether the error is really happening on the UNIQUEIDENTIFIER column. I suspect that either (a) the error is happening on a different column in the table, and you haven’t verified all of your string lengths, or (b) there is a trigger on the table and the error is happening there.

If you use proper parameters instead of just throwing a string together, you can make sure that each parameter is defined exactly as it is in the table.