如何在c＃中使用SQL Server存储过程数值参数

Question

I'm using the following SQL Server stored procedure in one of my C# projects.

create procedure [dbo].[TestRecordSelect]
@OMarks numeric(3,1) output
as 
begin
select @OMarks = isnull(sum(cast(OMarks as numeric(3,1))),0) from Marks 
end

and I'm getting the desired result ie 24.9 when executing the procedure in SQL Server. But when I'm using the same procedure in my C# project and calling the @OMarks as follows

cmd.Parameters.Add("@OMarks", SqlDbType.Decimal).Direction = ParameterDirection.Output;
tbomarks.Text = cmd.Parameters["@OMarks"].Value.ToString();  

I'm getting 25 instead of 24.9 that is the rounded up data.

My problem is I don't want to get 25. I want to get 24.9 in tbomarks

Answer 1

SqlParameter param = new SqlParameter("@OMarks", SqlDbType.Decimal);
param.Direction = ParameterDirection.Output;
param.Precision = 3;
param.Scale = 1;
cmd.Parameters.Add(param);

http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlparameter.scale.aspx

Answer 2

In your C#, you haven't specified the Scale (or Precision) of your parameter, which means you get zero decimal places.

Data may be truncated if the Scale property is not explicitly specified and the data on the server does not fit in scale 0 (the default)

Precision and Scale are required for output parameters