Entity Framework: “Store update, insert, or delete statement affected an unexpected number of rows (0).” [closed]

Answer 1

I got this same error because part of the PK was a datetime column, and the record being inserted used DateTime.Now as the value for that column. Entity framework would insert the value with millisecond precision, and then look for the value it just inserted also with millisecond precision. However SqlServer had rounded the value to second precision, and thus entity framework was unable to find the millisecond precision value.

The solution was to truncate the milliseconds from DateTime.Now before inserting.