Must declare scalar variable @Id

Question

I'm trying to get specific lecture id files and display it to students from HomeWorkTable

Additional information : System.Data.SqlClient.SqlException: 'Must declare the scalar variable "@id".'

private void LoadData2()
    {
        using (SqlConnection cn = GetSqlConnection())
        {
            string query = "SELECT HomeWorkID,FileName,Extension FROM HomeWorkTable WHERE LectureID=@id";
            SqlDataAdapter adp2 = new SqlDataAdapter(query, cn);
            DataTable dt2 = new DataTable();
            adp2.Fill(dt2);

            if (dt2.Rows.Count > 0)
            {
                dataGridView2.DataSource = dt2;
            }
        }
    }

    private void groupBox2_Enter(object sender, EventArgs e)
    {
        LoadData2();
    }

Duplicate of: [c# Using Parameters.AddWithValue in SqlDataAdapter](https://stackoverflow.com/questions/13276602/c-sharp-using-parameters-addwithvalue-in-sqldataadapter). Note: although the question is asking about `AddWithValue()`, you should follow the advice in [Steve's answer](https://stackoverflow.com/a/13276651/8967612) and use `Add()` instead. — 41686d6564 stands w. Palestine, Jun 26 '21 at 08:27
@Luuk That one is not very helpful because the OP is not using a `SqlCommand` _directly_. — 41686d6564 stands w. Palestine, Jun 26 '21 at 08:31
@41686d6564: The first parameter to `SqlCommand` is a `SqlCommand` — Luuk, Jun 26 '21 at 08:35
oops, copied wrong info... I did mean to say: The first parameter to `SqlDataAdapter` is a `SqlCommand` — Luuk, Jun 26 '21 at 09:48

Must declare scalar variable @Id

0 Answers0