Question

Can someone tell me why this code produces error?

The C# code

DateTime now = DateTime.Now;
DateTime after1month = DateTime.Now.AddMonths(1);

The query it produce

SELECT * FROM TABLE WHERE THEDATE BETWEEN 'now' AND 'after1month' 

Any help is appreciated.
Thx

Answer 1

This should look more like this:

DateTime now = DateTime.Now;
DateTime after1month = DateTime.Now.AddMonths(1);

SqlCommand cmd = new SqlCommand("SELECT * FROM TABLE WHERE THEDATE BETWEEN @now AND @after1month", connection);
cmd.Parameters.Add(new SqlParameter("@now", System.Data.SqlDbType.DateTime).Value = now);
cmd.Parameters.Add(new SqlParameter("@after1month", System.Data.SqlDbType.DateTime).Value = after1month);

Sometimes you can do it directly on SQL Server side using query:

SELECT * FROM TABLE WHERE THEDATE BETWEEN getdate() AND dateadd(mm, 1, getdate())

without parameters from .NET.

Added (after comment):

dateadd is a SQL Server function that allows to add a specyfic interval to date and returns it.

In this case dateadd(mm, 1, getdate()) adds one (1) month (mm) to current datetime (getdate()). More info on datepart identifiers and function itself on MSDN dateadd.