当用户使用他的 Vendor_ID 和密码登录时,他将根据条件重定向到 2 个不同的页面。如果他已经在网站上注册并且他的注册得到了网络管理员的批准,他将重定向到“RegPage1.aspx”,否则重定向到“ApprovalStatus.aspx”。如果用户输入了错误的 Vendor_ID 或密码,它将抛出错误消息“输入有效的 VendorID 或密码”。所以我写了如下的C#代码。它工作正常,但任何人都可以通过合并两个 SQL 查询来帮助我简单地做到这一点,检查“User_Info”表中的 vendor_ID 可用性和“Company_Info”表中的 ApprovalStatus 检查?
    protected void BtnHomeUserSubmit_Click(object sender, EventArgs e)
    {            
    SqlConnection SqlCon = new SqlConnection(GetConnectionString());  
    try      
    {             
      if ((txtHomeUsername.Text == "") || (txtHomePassword.Text == ""))        
      {               
        ScriptManager.RegisterStartupScript(this, this.GetType(), "Alert", "alert ('Enter valid  VendorID or Password');", true); 
      }             
      else           
      {       
         var da1 = new SqlDataAdapter("select * from User_Info where Vendor_ID='" +  txtHomeUsername.Text.Trim() + "'", SqlCon);                
        var dt1 = new DataTable();          
        da1.Fill(dt1);         
        if (dt1.Rows.Count > 0)        
        {            
         var da2 = new SqlDataAdapter("select * from Company_Info where Approval_Status='NO' AND Vendor_ID='" + txtHomeUsername.Text.Trim() + "'", SqlCon);        
              var dt2 = new DataTable();    
              da2.Fill(dt2);            
         if (dt2.Rows.Count > 0)       
         {            
           string url = "ApprovalStatus.aspx";     
           ClientScript.RegisterStartupScript(this.GetType(), "callfunction", "alert('Your Vendor ID is already registered');window.location.href = '" + url + "';", true);  
         }        
         else          
         {                      
             Response.Redirect("RegPage1.aspx?Parameter=" + Server.UrlEncode (txtHomeUsername.Text));        
         }       
     }          
       ScriptManager.RegisterStartupScript(this, this.GetType(), "Alert", "alert('Enter valid  VendorID or Password');", true);     
         }      
    }       
   finally   
   {      
    SqlCon.Close();    
   }       
   }