C# MS Access INNER 加入语法错误答案

【问题标题】：C# MS Access INNER Joining syntax errorC# MS Access INNER 加入语法错误
【发布时间】：2018-05-16 14:17:54
【问题描述】：

我正在使用 MS Access 2003 生成 DataGridView 的 DataSource，当我启动程序时，它会抛出：

    "Syntax error (no operator) in expression " k.Ka = p1.Id                 
       INNER JOIN Person AS p2 ON k.Kc1 = p2.Id
       INNER JOIN Person AS p3 ON k.Kc3 = p3.Id "

我的代码：

     try
            {

                using (OleDbConnection conn = new OleDbConnection(connecString))
                {

                    conn.Open();

       OleDbCommand cmd = new OleDbCommand(@"Select k.[Desc],k.Family,k.Num,p1.Name 
            AS KeyAdmin, p2.Name AS KeyCustodian1, p3.Name AS KeyCustodian3,p4.Name
            AS SecurityOfficer,p5.Name AS ServiceIT
            FROM KC AS k
            INNER JOIN Person AS p1 ON k.Ka = p1.Id                 
            INNER JOIN Person AS p2 ON k.Kc1 = p2.Id
            INNER JOIN Person AS p3 ON k.Kc3 = p3.Id       
            INNER JOIN Person AS p4 ON k.So = p4.Id  
            INNER JOIN Person AS p5 ON k.It = p5.Id
            WHERE k.Num = @Num;", conn);

               OleDbDataAdapter adapt = new OleDbDataAdapter(cmd);

               cmd.Parameters.AddWithValue("@num", form.comboKC.SelectedValue);


               DataTable dt = new DataTable();

               adapt.Fill(dt);
               form.dataGridView1.DataSource = dt;
               conn.Close();

           }

我是一名学生，我看不到我的错误，而且我大部分时间都在使用它，我的主管也不能，所以......我来了！谢谢你的时间，

【问题讨论】：

直接在 Access 中运行时查询是否有效？
自从我上次使用 ms-access 以来已经很久了，但我记得它喜欢括号。尝试ON (k.Ka = p1.Id) 进行所有连接。
form.comboKC.SelectedValue 是否返回一个有效值供您选择？

标签： c# sql ms-access

【解决方案1】：

MS Access 的 SQL 方言需要围绕 FROM 和 JOIN 子句的括号配对。考虑以下调整。一定要转义 Name，reserved word。

SELECT k.[Desc], k.Family, k.Num, p1.[Name] AS KeyAdmin, p2.[Name] AS KeyCustodian1, 
       p3.[Name] AS KeyCustodian3, p4.[Name] AS SecurityOfficer, p5.[Name] AS ServiceIT
FROM ((((KC AS k
INNER JOIN Person AS p1 ON k.Ka = p1.Id)                
INNER JOIN Person AS p2 ON k.Kc1 = p2.Id)
INNER JOIN Person AS p3 ON k.Kc3 = p3.Id)       
INNER JOIN Person AS p4 ON k.So = p4.Id)  
INNER JOIN Person AS p5 ON k.It = p5.Id
WHERE k.Num = @Num;

【讨论】：