c# - 无法在 SQL c# 中更新表

Question

我有一个名为 Town 的表，它包含玩家和玩家建筑物之间的关系。该表具有以下列:用户标识(整数)建筑编号(整数)数字(整数)

我已经成功地为玩家插入了一个新建筑，但现在我无法更新玩家的特定行。

我有这个代码:

if (!existPlayerBuilding(userid, buildingid))
            {
                SqlConnection sqlcon = new SqlConnection(connectionString);
                string query = "INSERT INTO Town VALUES(@userid, @buildingid, @number)";
                SqlCommand sqlcom = new SqlCommand(query, sqlcon);

                sqlcom.Parameters.Add("@userid", userid);
                sqlcom.Parameters.Add("@buildingid", buildingid);
                sqlcom.Parameters.Add("@number", number);

                try
                {
                    sqlcon.Open();
                    sqlcom.ExecuteNonQuery();
                    sqlcon.Close();
                }
                catch (Exception i)
                {
                    lblTestlabel.Text = "SQL FEILET";
                }
                lblTestlabel.Text = "Bygningen ble kjøpt!!!!";
            }
            else
            {
                SqlConnection sqlcon = new SqlConnection(connectionString);
                string query = "UPDATE Town VALUES(@userid, @buildingid, @number) WHERE userid = @userid AND buildingid = @buildingid";
                SqlCommand sqlcom = new SqlCommand(query, sqlcon);

                sqlcom.Parameters.Add("@userid", userid);
                sqlcom.Parameters.Add("@buildingid", buildingid);
                sqlcom.Parameters.Add("@number", number);

                try
                {
                    sqlcon.Open();
                    sqlcom.ExecuteNonQuery();
                    sqlcon.Close();
                }
                catch (Exception i)
                {
                    lblTestlabel.Text = "SQL FEILET";
                }
                lblTestlabel.Text = "Bygningen ble kjøpt!!!!";
            }

如果玩家已经拥有具有给定 ID 的建筑物，则 existPlayerBuilding 方法返回 true，否则返回 false。当我运行并测试我是否可以为构建的用户更新号码时，什么也没有发生。

Answer 1

SQL 中更新的语法是

UPDATE Town
SET number = @number 
WHERE userid = @userid AND buildingid = @buildingid