我的更新查询不起作用。 我正在使用Visual Studio 2015，并尝试更新访问数据库

Question

Below is my code for the update query, everything appears to be working fine, but the database does not update.

public int ChangeProduct(string _ProductID, double _ProductPrice)
    {
        int a = 0;
        string queryString = "UPDATE product SET productPrice = @productPrice WHERE productID = @productId";
        using (OleDbConnection connection = new OleDbConnection(connectionString))
        {

            OleDbCommand updateProduct = new OleDbCommand(queryString, connection);
            updateProduct.Parameters.AddWithValue("@productId", _ProductID);
            updateProduct.Parameters.AddWithValue("@productPrice", _ProductPrice);
            connection.Open();
            a = updateProduct.ExecuteNonQuery();
            connection.Close();
        }
        return a;
    }

Answer 1

Apparently Access doesn't care about the parameterized names, so much as the order they appear in. So by changing the code to below, it works.

public int ChangeProduct(string _ProductID, double _ProductPrice)
    {
        int a = 0;
        string queryString = "UPDATE product SET productPrice = @productPrice WHERE productID = @productId";
        using (OleDbConnection connection = new OleDbConnection(connectionString))
        {

            OleDbCommand updateProduct = new OleDbCommand(queryString, connection);
            updateProduct.Parameters.AddWithValue("@productPrice", _ProductPrice);
            updateProduct.Parameters.AddWithValue("@productId", _ProductID);
            connection.Open();
            a = updateProduct.ExecuteNonQuery();
            connection.Close();
        } 
        return a;
    }