ASP.NET存储过程方法不起作用

Question

I have this method that is calling a stored procedure:

public List<BarcodeClass> CheckTagId(int tagId)
{
    barcodes = new List<BarcodeClass>();
    try
    {
        using (SqlCommand command = new SqlCommand("uspCheckTagId", connection))
        {
            command.CommandType = CommandType.StoredProcedure;
            SqlParameter parameter = new SqlParameter("@TG", SqlDbType.Int)
            {
                Direction = ParameterDirection.Input,
                Value = tagId
            };
            command.Parameters.Add(parameter);
            connection.Open();
            SqlDataReader reader = command.ExecuteReader();
            while (reader.Read())
            {
            }
        }
    }
    finally
    {
        connection.Close();
    }
    
    return barcodes;
}

My problem is this does not work. I just get this message: An error has occurred. I know its not the connection to the database because if I change the stored procedures name to another stored procedure it doesnt return that error message. I have a feeling it has something to do with this part:

SqlParameter parameter = new SqlParameter("@TG", SqlDbType.Int)
{
    Direction = ParameterDirection.Input,
    Value = tagId
};

because I am passing in an int, if I use another stored procedure with a NVarChar and pass in a string this works! this there something wrong with the way I am passing in the int as parameter?

Here is the stored procedure:

    declare @TG int

    declare @L1R nchar(10) -- Label1 Return Variable
    declare @L2R nchar(10) -- Label2 Return Variable
    declare @L3R nchar(10) -- Label3 Return Variable
    declare @L4R nchar(10) -- Label4 Return Variable
    declare @LD1R nchar(15) -- LData1 Return Variable
    declare @LD2R nchar(15) -- LData2 Return Variable
    declare @LD3R nchar(15) -- LData3 Return Variable
    declare @LD4R nchar(15) -- LData4 Return Variable
    set @TG = 10001
    exec uspCheckTagId @TG, @L1 = @L1R output, @L2 = @L2R output, @L3 = @L3R output, @L4 = @L4R output,  @LD1 = @LD1R output, @LD2 = @LD2R output, @LD3 = @LD3R output, @LD4 = @LD4R output
    print @L1R
    print @L2R
    print @L3R
    print @L4r
    print @LD1R
    print @LD2R
    print @LD3R
    print @LD4r

Please help! I can't debug this because the database only works on the server I am pushing to and I dont have access to this server.

Answer 1

The syntax of creating a SP in sql server is:

CREATE PROCEDURE [schema].[procName]
    @param1 int, 
    @param2 bit
AS
BEGIN
    -- SP Logic
    declare @someVar int, -- note this is a variable, not a parameter.
            @anotherVar varchar(10)

    -- select, updates, deletes, etc
END

What you've posted as your proc definition (which was incomplete) does not have a parameter name @TG , but rather a variable. If you correct your proc to follow the above example, using parameters rather than variables, that should solve your immediate problem.

Additionally, based on your code comments, it looks like you're attempting to use output parameters. those need to be set up in the SP declaration (just as normal parameters) but with the out or output modifier.

It seems you want something like this:

create procedure mySpName
    @TG int, -- input parameter
    @L1R nchar(10) out, -- output parameter -- Label1 Return Variable
    @L2R nchar(10) out, -- Label2 Return Variable
    @L3R nchar(10) out, -- Label3 Return Variable
    @L4R nchar(10) out, -- Label4 Return Variable
    @LD1R nchar(15) out, -- LData1 Return Variable
    @LD2R nchar(15) out, -- LData2 Return Variable
    @LD3R nchar(15) out, -- LData3 Return Variable
    @LD4R nchar(15) out -- LData4 Return Variable
AS
BEGIN
    -- SP body
END

To use the parameters in your c# code you could use the example:

Add the parameter:

SqlParameter output = new SqlParameter("@L1R", SqlDbType.NVarChar);
output.Direction = ParameterDirection.Output;
cmd.Parameters.Add(output);

Read the parameter:

string L1R = cmd.Parameters["@L1R"].Value.ToString();