使用top命令时出现Sql查询错误 [英] Sql query error while using top command

问题描述

这里我使用Mysql和Asp.Net找到前5名学生。但是我收到以下错误

 conn1。< span class =code-keyword> Open （）; 
 conn2。打开（）; 
 string sql1 =  选择TOP 5`btechstudent_details`.Regd_no，Sname，Btech，Branch来自btechstudent_details，btechstudent_academics在哪里`btechstudent_details`.Regd_no =`btechstudent_academics`.Regd_no订购Btech DESC;; 
 MySqlCommand com1 = new MySqlCommand（sql1，conn1）; 
 MySqlDataAdapter da1 = new MySqlDataAdapter（com1）; 
 DataSet ds = new DataSet（）; 
 da1.Fill（ds，  Regd_no）; 
 Show.DataSource = ds.Tables [  Regd_no]; 
 Show.DataBind（）; 

错误 -  SQL中有错误句法;检查与MySQL服务器版本对应的手册，以便在'5`btechstudent_details`附近使用正确的语法.Regd_no，Sname，Btech，Branch FROM btechstudent_details，bt'在第1行

解决方案

据我所知，MySQL不支持TOP子句。相当于LIMIT



所以相当于

  SELECT   TOP   5  *  FROM  YourTable 

是

  SELECT  *  FROM  YourTable LIMIT  0 ， 5  

onn1.Open（）;

conn2.Open（）;

string sql1 =select TOP 5 btechstudent_details.Regd_no，Sname，Btech，Branch FROM btechstudent_details，btechstudent_academics WHERE btechstudent_details.Regd_no = btechstudent_academics.Regd_no ORDER BY Btech DESC;;

MySqlCommand com1 = new MySqlCommand（sql1，conn1）;

MySqlDataAdapter da1 = new MySqlDataAdapter（com1）;

DataSet ds = new DataSet（）;

da1.Fill（ds，Regd_no）;

Show.DataSource = ds.Tables [Regd_no];

Show.DataBind（）;





从SQL查询中删除单引号。



希望这会有所帮助。

Here I use Mysql with Asp.Net to find top 5 students.But I get the following error

conn1.Open();
                conn2.Open();
                string sql1 = "select TOP 5 `btechstudent_details`.Regd_no,Sname,Btech,Branch FROM btechstudent_details,btechstudent_academics WHERE `btechstudent_details`.Regd_no=`btechstudent_academics`.Regd_no ORDER BY Btech DESC;";
                MySqlCommand com1 = new MySqlCommand(sql1, conn1);
                MySqlDataAdapter da1 = new MySqlDataAdapter(com1);
                DataSet ds = new DataSet();
                da1.Fill(ds, "Regd_no");
                Show.DataSource = ds.Tables["Regd_no"];
                Show.DataBind();

ERROR-You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '5 `btechstudent_details`.Regd_no,Sname,Btech,Branch FROM btechstudent_details,bt' at line 1

解决方案

As far as I know MySQL does not support the TOP clause. The equivalent is LIMIT

So the equivalent of

SELECT TOP 5 * FROM YourTable

is

SELECT * FROM YourTable LIMIT 0,5

onn1.Open();
conn2.Open();
string sql1 = "select TOP 5 btechstudent_details.Regd_no,Sname,Btech,Branch FROM btechstudent_details,btechstudent_academics WHERE btechstudent_details.Regd_no=btechstudent_academics.Regd_no ORDER BY Btech DESC;";
MySqlCommand com1 = new MySqlCommand(sql1, conn1);
MySqlDataAdapter da1 = new MySqlDataAdapter(com1);
DataSet ds = new DataSet();
da1.Fill(ds, "Regd_no");
Show.DataSource = ds.Tables["Regd_no"];
Show.DataBind();


Remove single quotes from SQL query.

Hope this will help.

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