如何修复 ExecuteNonQuery 错误

Question

An exception is thrown on ExecuteNonQuery , how can I fix it?

string sqlQuery = "INSERT INTO transaction(ID,item_name,quantity,price,T_date) values (?,?,?,?,?)";
using (OleDbConnection conn = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\\KCdb.accdb"))
using (OleDbCommand cmd = new OleDbCommand(sqlQuery, conn))
{
    conn.Open();
    cmd.Parameters.AddWithValue("@ID", id);
    cmd.Parameters.AddWithValue("@item_name", item.ToString());
    cmd.Parameters.AddWithValue("@quantity", quantity);
    cmd.Parameters.AddWithValue("@price", price);
    cmd.Parameters.AddWithValue("@T_date", dt.ToString());
    cmd.ExecuteNonQuery();
}

Answer 1

For guiding you, we need the exception , because there will be different reasons of failure. But as I can see in your code there are some casts in assigning value to parameters, when your parameter is of DateTime type you should pass a DateTime as its value not a string. SO I think you should change cmd.Parameters.AddWithValue("@T_date", dt.ToString()); to cmd.Parameters.AddWithValue("@T_date", dt);