我如何将Sql Sum标记为C＃ [英] How Do I Sql Sum Get To Label C#

问题描述

亲爱的朋友们，



我需要在sql sum下打印到c＃windows form应用程序中。这是我正在使用的代码。但是我收到了一个错误。



SQL查询为休闲。这个工作正在工作

  SELECT  SUM（COUNT） FROM  Count_EPF  WHERE   date  = '  2015年6月17日'> 

转换从字符串转换datetime时失败



听到我的代码

  string  query =   SELECT SUM（ COUNT）FROM Count_EPF WHERE date ='@ C'; 
 
 使用（SqlCommand cmd =  new  SqlCommand（query，conn））
 {
 cmd.Parameters.AddWithValue（  @ C，dateTimePicker1.Text ）; 
 
 cmd.ExecuteNonQuery（）; 
  object  result = cmd.ExecuteScalar（）; 
 txtView.Text = Convert.ToString（result）; 

解决方案

删除引号：

 string query =   SELECT SUM（COUNT）FROM Count_EPF WHERE date ='@ C '; 

成为：

字符串查询=   SELECT SUM（COUNT）FROM Count_EPF WHERE date = @C; 

否则参数名称在SQL字符串中，不会被视为参数完全。





哦，不要传递字符串 - 直接传递DateTime，值：

 cmd.Parameters.AddWithValue（  @ C，dateTimePicker1.Value）; 

这样，SQL就不必将字符串解释为具有可能导致的所有可能误解的日期。

[/编辑]

Dear friends,

I need to print below sql sum into c# windows form application. here is the code i was using for this. but i'm getting an error.

SQL Query as fallows. this one is working

SELECT SUM (COUNT)  FROM  Count_EPF WHERE date = '6/17/2015'>

conversion failed when converting datetime from character string

hear is my code

string query = "SELECT SUM (COUNT)  FROM  Count_EPF WHERE date = '@C' ";

                using (SqlCommand cmd = new SqlCommand(query, conn))
                {
                    cmd.Parameters.AddWithValue("@C", dateTimePicker1.Text);

                    cmd.ExecuteNonQuery();
                    object result = cmd.ExecuteScalar();
                    txtView.Text = Convert.ToString(result);

解决方案

Remove the quotes:

string query = "SELECT SUM (COUNT)  FROM  Count_EPF WHERE date = '@C' ";

Becomes:

string query = "SELECT SUM (COUNT)  FROM  Count_EPF WHERE date = @C ";

Otherwise the parameter name is within an SQL string and is not treated as a parameter at all.

[edit]
Oh, and don't pass the string - pass the DateTime, value directly:

cmd.Parameters.AddWithValue("@C", dateTimePicker1.Value);

That way, SQL doesn't have to interpret the string into a date with all the possible misinterpretations that can cause.
[/edit]

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