System.Data.SqlClient.SqlException：“将 nvarchar 值转换为数据类型 int 时转换失败。”

Question

I have creates a database and I am trying to INSERT INTO TABLE with the following code:

string sqlquery = "INSERT INTO Runner VALUES (@firstName, @lastName, @amount, @category, @city, @charity, @route)";
cmd = new SqlCommand(sqlquery, conn);

conn.Open();

cmd.Parameters.AddWithValue("@firstName", txtFirstName.Text.ToString());
cmd.Parameters.AddWithValue("@lastName", txtLastName.Text.ToString());
cmd.Parameters.AddWithValue("@amount", Convert.ToInt32(txtMoney.Text));
cmd.Parameters.AddWithValue("@category", cbBoxCategory.ValueMember);
cmd.Parameters.AddWithValue("@city", cbBoxCity.ValueMember);
cmd.Parameters.AddWithValue("@charity", cbBoxCharity.ValueMember);
cmd.Parameters.AddWithValue("@route", cbBoxRoute.ValueMember);

cmd.ExecuteNonQuery();
conn.Close();

When I run it, I get this error:

System.Data.SqlClient.SqlException: 'Conversion failed when converting the nvarchar value 'id' to data type int.'

All my cbBox (comboBox) need to leave a INT , I understand that is need to convert to NVARCHAR to INT , I try to use Convert.Into32(cbBox.Category.ValueMember) but without success.

I have tried everything with no success.

Answer 1

After looking for other people answer I find this solution.

string sqlquery = "INSERT INTO Runner (firstName, lastName, amount, categoryID, cityID, charityID, routeID) VALUES (@firstName, @lastName, @amount, @category, @city, @charity, @route)";
cmd = new SqlCommand(sqlquery, conn);
conn.Open();
cmd.Parameters.Add("@firstName", SqlDbType.VarChar, 50).Value =  txtFirstName.Text;
cmd.Parameters.Add("@lastName", SqlDbType.VarChar, 50).Value = txtLastName.Text;
cmd.Parameters.Add("@amount", SqlDbType.Int).Value = txtMoney.Text;
cmd.Parameters.Add("@category", SqlDbType.Int).Value = cbBoxCategory.SelectedValue;
cmd.Parameters.Add("@city", SqlDbType.Int).Value = cbBoxCity.SelectedValue;
cmd.Parameters.Add("@charity", SqlDbType.Int).Value = cbBoxCharity.SelectedValue;
cmd.Parameters.Add("@route", SqlDbType.Int).Value = cbBoxRoute.SelectedValue;
cmd.ExecuteNonQuery();
MessageBox.Show("New Runner has been registered!");
conn.Close();

By using Convert.ToInt32(cbBoxRoute.SelectedValue)

Here is the link where I find my solution:

Insert ID into SQL from C# Combo box