如何使用asp.net将Datatable传递给SQL Server

Question

I am working on an asp.net web application where I am passing a DataTable from an asp.net application to SQL Server stored procedure.

My table in SQL Server is

Student(ID bigint, Name nvarchar(max), Reg bigint).

In this table, the ID is the primary key and auto incremented. My c# code to pass a DataTable to stored procedure on button click is:

protected void btnSubmit_Click(object sender, EventArgs e)
{
    try
    {
        DataTable dt = new DataTable("Student");

        dt.Columns.Add("Reg", typeof(long));
        dt.Columns.Add("Name", typeof(string));

        // Create a new row
        for (int i = 0; i < 3; i++)
        {
            DataRow NewRow = dt.NewRow();

            if (i == 0)
            {
                NewRow["Name"] = "Raunak";
                NewRow["Reg"] = Convert.ToInt64(1); ;
            }
            if (i == 1)
            {
                NewRow["Name"] = "Vikash";
                NewRow["Reg"] = Convert.ToInt64(1);
            }
            if (i == 2)
            {
                NewRow["Name"] = "Deepak";
                NewRow["Reg"] = Convert.ToInt64(1);
            }

            dt.Rows.Add(NewRow);
        }

        dt.AcceptChanges();

        string constring = ConfigurationManager.ConnectionStrings["conString"].ConnectionString;
        SqlConnection cnn = new SqlConnection(@"Data Source=.\sqlexpress; Initial Catalog=builderERP; Integrated Security=True;");           

        SqlCommand selectCommand = new SqlCommand("Student_Insert_Update_Delete", cnn);
        selectCommand.CommandType = CommandType.StoredProcedure;
        SqlParameter tvpParam = selectCommand.Parameters.AddWithValue("@Student", dt);
        tvpParam.SqlDbType = SqlDbType.Structured;

        cnn.Open();

        int xx = selectCommand.ExecuteNonQuery();

        if (xx > 0)
        {
            lblMsg.Text = "Data Successfully Inserted.";
        }
        else
        {
            lblMsg.Text = "Data Insertion Failed.";
        }
        cnn.Close();

    }
    catch (Exception ex)
    {
        throw (ex);
    }
}

My stored procedure in T-SQL is :

CREATE PROCEDURE [dbo].[Student_Insert_Update_Delete]
(
    @Student AS [dbo].[StudentTableVal] Readonly
)
AS
BEGIN   
INSERT INTO Student(Name,Reg) 
        SELECT Name,Reg FROM @Student
        --commit transaction

 END

I have created a table type as:

CREATE TYPE StudentTableVal AS TABLE
(
    Name NVARCHAR(max),
    Reg bigint
) 

But when I click the button to insert DataTable into Student table I get this error:

Error converting data type nvarchar to bigint.
The data for table-valued parameter "@Student" doesn't conform to the table type of the parameter.

Please help me someone.

Answer 1

The only thing I can think of is that it's not mapping the column by name but by index so try to invert the column definition and see what happens:

    dt.Columns.Add("Name", typeof(string));
    dt.Columns.Add("Reg", typeof(long));

Hope it works.

Answer 2

尝试使用Print命令打印SQL中的@Student参数值一旦获得动态生成的完整SQL字符串，请尝试执行Student_Insert_Update_Delete存储过程中编写的完整sql语句，这样您就会知道语句中缺少什么