Question

I am new to SQL (started today itself), how to add data of dataset to the database table when the table in database has the first column as automatic generating numbers i.e., (IDENTITY (1,1))

I have DataSet something like this

  name    age    location

   x      30       yyy
   y      20       ppp

The table in Database is something like this

  Id(auto)   name    age    location

  --------  no data  --------------

First of all I am filling the Dataset from the database table.
Since the first column is autogenerated I cant even add new values to DataSet.
If I say

 dsMainDoctors.Tables[0].Rows.Add( /* first column is autogenerated so I am leaving it*/
                secondColumn,
                thirdColumn,
                fourthColumn,
                FifthColumn);

Error –> Input string was not in a correct format.Couldn’t store in Doctor_ID Column. Expected type is Int32.

The code I am trying is: (When I given the first column value manually in the DataSet)

        SqlConnection conn = new SqlConnection(strConn);
        SqlCommand cmd = new SqlCommand(strQuery, conn);
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        conn.Open();
        da.Update(ds.Tables[0]);  //ERROR :- Update requires a valid InsertCommand when passed DataRow collection with new rows.
        conn.Close();
        conn.Dispose();
        cmd.Dispose();

---

 strQuery --> "delete from [dbo].[" + table_name + "]";

I could have searched this before asking but I dont know what keywords I should use
Please answer in comments if it is very easy question.

Answer 1

Okay, the following code will build that INSERT command properly for you. Also, please note, that if you’re concerned about disposing objects, use the using statement instead because it will call Dispose when exiting the statement.

SqlConnection conn = new SqlConnection(strConn);
SqlCommand cmd = new SqlCommand(strQuery, conn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
SqlCommandBuilder builder = new SqlCommandBuilder(da);

using (cmd)
{
    using (conn)
    {
        conn.Open();

        da.InsertCommand = builder.GetInsertCommand();
        da.Update(ds.Tables[0]);  //ERROR :- Update requires a valid InsertCommand when passed DataRow collection with new rows.

        conn.Close();
    }
}

EDIT

If you’re just wanting to delete the data in the database to rebuild it then that’s quite different than what you’re original question was implying. However, below is how simple that would be.

var strQuery = "delete from [dbo].[" + table_name + "]";
SqlConnection conn = new SqlConnection(strConn);
SqlCommand cmd = new SqlCommand(strQuery, conn);
var rowsAffected = cmd.ExecuteNonQuery();

// do something with rowsAffected if you want

// now you can build `insert` statements if you want
// to put more data into it, which you could use the
// previous example for that