Linq SELECT与ExecuteQuery [英] Linq SELECT with ExecuteQuery

问题描述

我得到了错误:

类型'System.Int32 []'必须声明一个默认(无参数)构造函数，以便在映射期间进行构造.

The type 'System.Int32[]' must declare a default (parameterless) constructor in order to be constructed during mapping.

使用代码:

var gamePlayRecord = db.ExecuteQuery<int[]>("SELECT UserID, IPID, GameID FROM ArcadeGames WHERE ID = " + gamePlayRecordID).Single();
var userID = gamePlayRecord[0];
var ipID = gamePlayRecord[1];
var gameID = gamePlayRecord[2];

我知道这是错误的，但是有人可以告诉我如何正确地进行操作，而不必创建新对象吗?

I know this is wrong, but can someone show me how to do it correctly without needing to create a new object preferably?

推荐答案

此查询的结果不是 int [] ，而是一行带数字的

Result of this query is not int[] but one row with numbers.

不好的解决方案:用于每个数字:

not good solution: use for every number:

int userID = db.ExecuteQuery<int>("SELECT UserID FROM ArcadeGames WHERE ID = " + gamePlayRecordID).Single();
int ipID = db.ExecuteQuery<int>("SELECT IPID FROM ArcadeGames WHERE ID = " + gamePlayRecordID).Single();
int gameID db.ExecuteQuery<int>("SELECT GameID FROM ArcadeGames WHERE ID = " + gamePlayRecordID).Single();

或创建sql查询

db.ExecuteQuery<int>(@"
SELECT UserID FROM ArcadeGames WHERE ID = {0}
UNION ALL
SELECT IPID FROM ArcadeGames WHERE ID = {0}
UNION ALL
SELECT GameID FROM ArcadeGames WHERE ID = {0}", 
gamePlayRecordID).ToList();

或创建课程...

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