No milliseconds value when reading DateTime values from a SQL database in C#

Question

I have high precision dates stored in an SQL server, e.g.

2009-09-15 19:43:43.910

However when I convert that value into a DateTime the mil

Answer 1

Here's how I'd try to troubleshoot this:

1. step through in the debugger and look at the type and value of reader[Timestamp"]. If the type is not SqlDateTime, that would make me suspicious-- I'd then look at the query to figure out why that column was returning another type instead of DATETIME (or DATETIME2, etc.)

2. if that value is SqlDateTime and it does contains milliseconds, then I'd look at the cast as the source of the problem. To validate this, I'd try (in debugger or code) SqlDataReader.GetDateTime() and SqlDataReader.GetSqlDateTime() to see if either returns the correct result. This admittedly seems really unlikely as source of the problem-- casting should work fine.

3. if that value from #1 is SqlDateTime but contains no milliseconds, then I'd look to an upstream problem in the database-- in other words your query is returning something without milliseconds. when you execute the exact same query in Management Studio, do you see milliseconds?

My guess is this is a query-related issue. But am intrigued to find our more.