操作数类型冲突：nvarchar与用户定义的表类型不兼容

Question

I'm new here and I'm facing a trouble currently, my scenario is that I wanted to insert and update data from Excel into a SQL Server table.

For the insert part it works perfectly but when it comes to update I have no idea how should I do that. I have search for few methods and I found this is the most comfortable for me by using stored procedure.

Here is my code that I'm using now. When I try it gave me this error:

Operand type clash: nvarchar is incompatible with user-defined table type

--- Stored procedure ---
CREATE PROCEDURE [dbo].[chkUpdate]
    @Operator IC_CHK READONLY
AS
BEGIN
    set nocount on;

    MERGE INTO tb_Operator c1
    USING @Operator c2 ON c1.IC = c2.IC

    WHEN MATCHED THEN
      UPDATE SET
            c1.Name = c2.Name,
            --c1.IC = c2.IC,
            c1.Email = c2.Email,
            c1.Status = c2.Status,
            c1.Datetime = c2.Datetime

    WHEN NOT MATCHED THEN
      INSERT VALUES(c2.Name, c2.IC, c2.Email, c2.[Status], c2.[Datetime]);
end

--- User-defined table type ---
CREATE TYPE [dbo].[IC_CHK] as table 
(
    [Id] [int] NULL,
    [Name] [nvarchar](50) NULL,
    [IC] [bigint] NULL,
    [Email] [nvarchar](MAX) NULL,
    [Status] [nvarchar](50) NULL,
    [Datetime] [datetime] NULL
)

VS 2010 code:

protected void btnImport_Click1(object sender, EventArgs e)
{
    int i = 0;

    try
    {
        string path = string.Concat(Server.MapPath("~/Excel/" + UploadExcel.FileName));
        UploadExcel.SaveAs(path);

        String strCon = string.Format("Provider=Microsoft.Ace.OLEDB.12.0;Data Source={0}; Extended Properties=Excel 12.0;",path);
        OleDbDataAdapter myda = new OleDbDataAdapter("SELECT * FROM [sheet1$]", strCon);

        DataTable myds = new DataTable();
        myda.Fill(myds);

        for (i = 0; i <= myds.Rows.Count - 1; i++)
        {
            String constr = ConfigurationManager.ConnectionStrings["conn"].ConnectionString;

            using (SqlConnection con = new SqlConnection(constr))
            using (SqlCommand cmd = new SqlCommand("chkUpdate"))
            {
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.Connection = con;

                cmd.Parameters.AddWithValue("@Operator", path);

                con.Open();
                cmd.ExecuteNonQuery();
                con.Close();
            }
        }

        MsgBox1.alert("Import success");
        View.Visible = true;

        vBinds();
    }
    catch (Exception ex)
    {
        MsgBox1.alert(ex.Message);
    }
}

Do check for me and I'm appreciate it. Thank you

P/S: I double confirm that my user-defined table type has the same data type with my table.

Answer 1

In the INSERT in your MERGE statement, I would recommend to explicitly define the columns you're inserting into. Most likely, that's the cause of the error - you're inserting your columns - but you're not specifying which target columns those should be inserted into.

Since you're not specifying that, you must supply values for each column in the table, in the exact order in which they are defined - is that really the case?? Eg what do you insert into your ID column in the table??

Assuming the ID column on your actual database table is an IDENTITY column, I would use (otherwise, you'd have to list ID in the list of columns to insert into as well and provide a value in the VALUES list of values):

WHEN NOT MATCHED THEN
  INSERT(Name, IC, Email, [Status], [DateTime])
  VALUES(c2.Name, c2.IC, c2.Email, c2.[Status], c2.[Datetime]);

and I would also recommend not to use T-SQL reserved keywords like status or datetime as your column names - you're just asking for trouble doing so. Use more expressive names - something that really relates to your business domain - not just datetime .....