简单的问题是,如何将MS Query中的字段值增加1？我想1(+1)添加到int在使用参数化方法,我的SQL Server数据库列.类似于对变量的i ++操作.我使用以下方法:
public static int UpdateFieldCount(int parameterId)
{
// variable to hold the number of rows updated or the success of the query
int updatesuccess = 0;
// build your connection string
string connectionstring = WebConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
SqlConnection conn = new SqlConnection(connectionstring);
// build your SQL Query statement
string SQLString = "UPDATE TableName SET TableField + 1 WHERE SomeFilterField = @ParameterID";
SqlCommand sqlcmd = new SqlCommand(SQLString, conn);
sqlcmd.Parameters.AddWithValue("@ParameterID", parameterID);
conn.Open();
updatesuccess = sqlcmd.ExecuteNonQuery();
conn.Close();
return updatesuccess;
} …我已经搜索并尝试了所有的东西,但无法想出这个.我想做一些简单的事情,但好像我做错了什么.基本上,任何已经存款的用户,我想要返回true,如果他们没有,我想返回false.我想这应该很容易,但我对此感到难过.
这是错误:
ConnectionString属性尚未初始化.
描述:执行当前Web请求期间发生未处理的异常.请查看堆栈跟踪以获取有关错误及其源自代码的位置的更多信息.
异常详细信息:System.InvalidOperationException:尚未初始化ConnectionString属性.
来源错误:
Line 59: Cmd.Parameters.AddWithValue("@UserID", userId);
Line 60: con.Open();
Line 61:
Line 62: result = (int)Cmd.ExecuteScalar();
这是堆栈跟踪的顶部:
[InvalidOperationException:ConnectionString属性尚未初始化.] System.Data.SqlClient.SqlConnection.PermissionDemand()+ 4879939 System.Data.SqlClient.SqlConnectionFactory.PermissionDemand(DbConnection outerConnection)+20 System.Data.ProviderBase.DbConnectionClosed.OpenConnection( DbConnection outerConnection,DbConnectionFactory connectionFactory)+117 System.Data.SqlClient.SqlConnection.Open()+122
这是我返回true或false的方法:
public static bool HasDeposit(int userId)
{
int result = 0;
//since executeScalar is intended to retreive only a single value
//from a query, we select the number of results instead of the email address
//of each matching result.
string queryTransaction = "SELECT COUNT(UserID) FROM Transaction WHERE TransactionTypeID = …尝试基于挑战匹配系统创建SQL Server查询.我想在查询中加入两个表:Users和ChallengeMatches.
表中的Users列是UserID, UserDisplayName
表中的ChallengeMatch列是ChallengeMatchID, ChallengerUserID, ChallengeeUserID
当然,所有ChallengeeUserID的和所有ChallengerUserID的都Users作为唯一用户列在表中.我希望查询要做的是每次挑战匹配(ChallengeMatch表中的行),返回UserDisplayName两个挑战参与者,例如PlayerName1,PlayerName2.
任何帮助,将不胜感激.
我的问题是:我有一个MS SQL查询,它结合了不同用户的游戏和游戏分数,并在两部分计算中使用聚合函数来获得综合得分.由于某种原因,计算的一部分(计算的第一部分 - 所玩的游戏)未在总分中使用(我称之为Algoscore).查询如下:
SELECT TOP 10
COUNT(TourScore.TourScoreID) AS GameCount,
AVG(GameScore.GameScore) AS AVGScore,
Users.UserID, Users.DisplayName,
(((COUNT(TourScore.TourScoreID) / 750) * .50) * 100)
+ (((AVG(GameScore.GameScore) / 14695) * .50) * 100) AS Algoscore
FROM TourScore INNER JOIN GameScore
ON TourScore.GameScoreID = GameScore.GameScoreID
INNER JOIN Users
ON GameScore.UserID = Users.UserID
WHERE (GameScore.ScoreDate BETWEEN '01/01/2013' AND '06/01/2013')
GROUP BY Users.UserID, Users.DisplayName
ORDER BY Algoscore DESC
SELECT的计算部分:
(((COUNT(TourScore.TourScoreID) / 750) * .50) * 100) + (((AVG(GameScore.GameScore) / 14695) * .50) * 100) AS Algoscore …