如何在1个查询中合并3个条件 [英] How to merge 3 conditions at 1 query

问题描述

您好，



如何在1个查询中加入3个条件，以便弹出消息框说3条件满了？

如果NewData则
 strSQL = 
SELECT Count（tblContact.Fullname，）AS CountFullname FROM tblContact& 
WHERE Fullname =& '& txtFullname.Text& '

SELECT Count（tblContact.Phone，）AS CountPhone FROM tblContact& 
WHERE Phone =& '& txtPhone.Text& '
 

SELECT Count（tblContact。电子邮件，）AS Countemail FROM tblContact& 
WHERE email =& '& txtemail.Text& '
 

我尝试过：



论坛，从句，示例代码。

解决方案

这与如何在VB中添加3个IF条件 - Visual Basic讨论板 [ ^ ] 。我注意到你仍然没有使用参数化查询，所以你的数据库仍然存在腐败或更糟的风险。

我也修复了你的SQL注入问题....你可能需要调整语法因为我的IDE都被占用所以我正在写这个直接

 StringBuilder sb =  new  Stringbuilder（  SELECT）; 
 sb.AppendLine（  NameCount =（SELECT Count（1）FROM tblContact WHERE FullName = @FullName） ）; 
 sb.AppendLine（ ，PhoneCount =（SELECT Count（1）FROM tblContact WHERE Phone = @Phone） ）; 
 sb.AppendLine（ ，EmailCount =（SELECT Count（1）FROM tblContact WHERE Email = @Email） ）; 
 
 
  string  strSQL = sb.ToString（）; 
 SqlCommand cmd =  new  SqlCommand（strSql， 连接）; 
 cmd.Parameters.AddWithValue（  @ FullName，txtFullname.Text）; 
 cmd.Parameters.AddWithValue（  @ Phone，txtPhone.Text）; 
 cmd.Parameters.AddWithValue（  @ Email，txtemail.Text）; 

Hello,

How to join 3 conditions at 1 query so messagebox pops up to say 3 condition is fullfilled ?

If NewData Then
        strSQL =
            " SELECT Count(tblContact.Fullname, ) AS CountFullname FROM tblContact " &
            " WHERE Fullname = " & "'" & txtFullname.Text & "'"

" SELECT Count(tblContact.Phone, ) AS CountPhone FROM tblContact " &
     " WHERE Phone = " & "'" & txtPhone.Text & "'"

" SELECT Count(tblContact.email, ) AS Countemail FROM tblContact " &
     " WHERE email = " & "'" & txtemail.Text & "'"

What I have tried:

Forums, clauses, sample codes.

解决方案

This is basically the same issue as How to add 3 IF conditions at VB - Visual Basic Discussion Boards[^]. And I note you are still not using parameterised queries, so your database is still at risk of corruption or worse.

I fixed your SQL Injection problem too.... You may have to adjust syntax as my IDE's are all occupied so I'm writing this direct

StringBuilder sb = new Stringbuilder("SELECT ");
sb.AppendLine("NameCount = (SELECT Count(1) FROM tblContact WHERE FullName = @FullName)");
sb.AppendLine(", PhoneCount = (SELECT Count(1) FROM tblContact WHERE Phone = @Phone)");
sb.AppendLine(", EmailCount = (SELECT Count(1) FROM tblContact WHERE Email = @Email)");


string strSQL = sb.ToString();
SqlCommand cmd = new SqlCommand(strSql, "connection");
cmd.Parameters.AddWithValue("@FullName", txtFullname.Text);
cmd.Parameters.AddWithValue("@Phone", txtPhone.Text);
cmd.Parameters.AddWithValue("@Email", txtemail.Text);

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