Question

为了防御性地准备我的问题，我在发布之前使用了Google，Bing和StackOv :-)。另外，我是MVC3的新手，仍然在努力解决框架的语法错综复杂问题。

我在下面的代码块中的SQL语句中出错，这让我很烦恼。语法显示正确。我使用Select * From ..简化了SQL语句，它返回数据就好了。

此外，如果有更好的方法（不使用EF对象），请务必接受建议。我非常喜欢看到SQL语句的灵活性和控制 - 要么就是习惯的形式，要么习惯于它： - ）。

提前致谢!!

@using System.Data.SqlClient;
@using System.Configuration;

@{
    Layout = null;
}
@{
    SqlConnection cn = null;
    cn = new SqlConnection(ConfigurationManager.ConnectionStrings["sqlConn"].ToString());
    cn.Open();
   SqlCommand cmd = new SqlCommand((@"SELECT DISTINCT" +
                                    "tblSBT.sname," +
                                    "tblSBDetails.sid," + 
                                    "tblSBDetails.assignedtrack," + 
                                    "tblSBDetails.maxtrack," + 
                                    "tblSBDetails.currentvals," + 
                                    "tblSBDetails.maxvals," + 
                                    "tblSBDetails.lastupdated" +
                                    "FROM" +         
                                        "tblSBT (NOLOCK)" +
                                    "LEFT OUTER JOIN" +
                                        "tblSBDetails (NOLOCK)" +
                                    "ON" +
                                        "tblSBT.sid = tblSBDetails.sid" +                      
                                    "WHERE" +
                                    "tblSBDetails.lastupdated > DateADD(n, -5, GETDATE())"+
                                    "ORDER BY" +
                                    "tblSBT.sname" +), cn);

    var myreader = cmd.ExecuteReader();
}

Answer 1

如果您正在使用@符号，则无需像执行此操作那样连接字符串。当你加入这样的字符串时，它也不是编写这段代码的最有效方式。

SqlConnection cn = null;
cn = new SqlConnection(ConfigurationManager.ConnectionStrings["sqlConn"].ToString());
cn.Open();
SqlCommand cmd = new SqlCommand((@"SELECT DISTINCT
        tblSBT.sname,
        tblSBDetails.sid,
        tblSBT.sname,
        tblSBDetails.sid, 
        tblSBDetails.assignedtrack,
        tblSBDetails.maxtrack,
        tblSBDetails.currentvals,
        tblSBDetails.maxvals,  
        tblSBDetails.lastupdated
        FROM    tblSBT (NOLOCK)
                    LEFT OUTER JOIN tblSBDetails (NOLOCK)
                        ON .sid = tblSBDetails.sid
        WHERE   tblSBDetails.lastupdated > DateADD(n, -5, GETDATE())
        ORDER BY    tblSBT.sname"), cn);

var myreader = cmd.ExecuteReader();

Answer 2

您必须在字符串之间添加空格。

SqlCommand cmd = new SqlCommand((@"SELECT DISTINCT " +
                                    "tblSBT.sname," +
                                    "tblSBDetails.sid," + 
                                    "tblSBDetails.assignedtrack," + 
                                    "tblSBDetails.maxtrack," + 
                                    "tblSBDetails.currentvals," + 
                                    "tblSBDetails.maxvals," + 
                                    "tblSBDetails.lastupdated" +
                                    " FROM" +         
                                        " tblSBT (NOLOCK)" +
                                    " LEFT OUTER JOIN" +
                                        " tblSBDetails (NOLOCK)" +
                                    " ON" +
                                        " tblSBT.sid = tblSBDetails.sid" +                      
                                    " WHERE" +
                                    " tblSBDetails.lastupdated > DateADD(n, -5, GETDATE())"+
                                    " ORDER BY" +
                                    " tblSBT.sname"), cn);

不要连接字符串，因为您使用的是multiline string literal @。

SqlCommand cmd = new SqlCommand(@"SELECT DISTINCT tblSBT.sname,tblSBDetails.sid,
                              tblSBDetails.assignedtrack,
                              tblSBDetails.maxtrack,
                              tblSBDetails.currentvals,
                              tblSBDetails.maxvals,
                              tblSBDetails.lastupdated
                              FROM tblSBT (NOLOCK)
                              LEFT OUTER JOIN
                              tblSBDetails (NOLOCK)
                              ON tblSBT.sid = tblSBDetails.sid
                              WHERE tblSBDetails.lastupdated > DateADD(n, -5, GETDATE())
                              ORDER BY tblSBT.sname",cn);

Answer 3

更好的调试方法是将字符串变量=设置为整个SQL语句，然后将其复制并粘贴到SQL Server Mgmt Studio中。您可能已经看到代码一起运行并确定了您的问题。

另外，我认为你真的不了解@符号在这里的用法。只有你的第一行“SELECT DISTINCT”被视为文字，你连接的其余字符串只是字符串，而不是字符串文字。实际上，在这种情况下甚至不重要。

你可能意味着什么

SqlCommand cmd = new SqlCommand((@"SELECT DISTINCT 
                                tblSBT.sname,
                                tblSBDetails.sid,
                                tblSBDetails.assignedtrack,
                                tblSBDetails.maxtrack,
                                tblSBDetails.currentvals,
                                tblSBDetails.maxvals,
                                tblSBDetails.lastupdated
                                 FROM
                                     tblSBT (NOLOCK)
                                 LEFT OUTER JOIN
                                     tblSBDetails (NOLOCK)
                                 ON
                                     tblSBT.sid = tblSBDetails.sid                    
                                 WHERE
                                 tblSBDetails.lastupdated > DateADD(n, -5, GETDATE())
                                 ORDER BY
                                 tblSBT.sname"), cn);

多行中的SQL语句抛出错误

3 个答案: