Solved

The variable 'sql' is assigned but its value is never used

Posted on 2009-05-13
3
670 Views
Last Modified: 2013-12-17
Good afternoon expert,

Getting error messages in VS 2005
The variable 'sql' is assigned but its value is never used
The variable 'connStringl' is assigned but its value is never used

But they are used at
dsToolkit.SelectCommand = sql;
and
dsToolkit.ConnectionString = connString;

So why does th compiler complain?

Allen



using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
 
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        //Default SQL statement which will be executed when no search conditions were entered
        String sql = "SELECT tblSecurity.Username, tblSecurity.First_Name, tblSecurity.Last_Name, tblSecurity.Company_number FROM tblSecurity";
        //Connection string - @@DBName will be replaced by the server name selected from the
        //Environment dropdown
        String connString = "DATA SOURCE = Labsdirvg600;Initial Catalog=TimeEntry;User ID=Labswirvg600;Password=Kling0n1";
        //A boolean field which is used to add a WHERE clause to the SQL statement
        //Boolean whereClauseAdded = false;
 
        //Connection string is formed here. cboEnvironment.SelectedItem.Value will return
        //the selected environment.
        //connString = connString.Replace("@@DBName", cboEnvironment.SelectedItem.Value);
    }
 
    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        if (query.Checked)
            sql = "SELECT * from tblSecurity where Username Like '%sm'";
        if (query.Checked)
 
            sql = "SELECT * from tblSecurity where Username Like '%jo'";
 
 
        //Set the connection string of the SQLDataSource here
        dsToolkit.ConnectionString = connString;
 
        //Atleast one search criteria must be entered by the user if a WHERE clause needs to be
        //added
 
        //Now, the dynamically created SQL statement needs to be assigned to the SQL Data source
        dsToolkit.SelectCommand = sql;
 
        //Finally, refresh the Grid, which will cause the data source to execute the above created
        //SQL and show the results in the grid
        grdPayroll.DataBind();
    }
 
}

Open in new window

0
Comment
Question by:9apit
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 143

Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 24379389
change:
 protected void btnSubmit_Click(object sender, EventArgs e)
    {
        sql = string.empty;
        if (query.Checked)
            sql = "SELECT * from tblSecurity where Username Like '%sm'";
        if (query.Checked)
 
            sql = "SELECT * from tblSecurity where Username Like '%jo'";
 

Open in new window

0
 

Author Comment

by:9apit
ID: 24379526
Angelll,

Installed code now get
Warning      2      The variable 'sql' is assigned but its value is never used      C:\Inetpub\wwwroot\TK090514\Default.aspx.cs      16      16      C:\...\TK090514\
Warning      3      The variable 'connString' is assigned but its value is never used      C:\Inetpub\wwwroot\TK090514\Default.aspx.cs      19      16      C:\...\TK090514\
Error      4      The name 'sql' does not exist in the current context      C:\Inetpub\wwwroot\TK090514\Default.aspx.cs      31      9      C:\...\TK090514\
Error      5      'string' does not contain a definition for 'empty'      C:\Inetpub\wwwroot\TK090514\Default.aspx.cs      31      22      C:\...\TK090514\
Error      6      The name 'query' does not exist in the current context      C:\Inetpub\wwwroot\TK090514\Default.aspx.cs      32      13      C:\...\TK090514\
Error      7      The name 'sql' does not exist in the current context      C:\Inetpub\wwwroot\TK090514\Default.aspx.cs      33      13      C:\...\TK090514\
Error      8      The name 'query' does not exist in the current context      C:\Inetpub\wwwroot\TK090514\Default.aspx.cs      34      13      C:\...\TK090514\
Error      9      The name 'sql' does not exist in the current context      C:\Inetpub\wwwroot\TK090514\Default.aspx.cs      36      13      C:\...\TK090514\
Error      10      The name 'connString' does not exist in the current context      C:\Inetpub\wwwroot\TK090514\Default.aspx.cs      42      38      C:\...\TK090514\
Error      11      The name 'sql' does not exist in the current context      C:\Inetpub\wwwroot\TK090514\Default.aspx.cs      52      35      C:\...\TK090514\
0
 
LVL 143

Accepted Solution

by:
Guy Hengel [angelIII / a3] earned 500 total points
ID: 24379560
sorry, I got the error message wrong.

the problem is that you define sql in the page load, instead of the class level
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
 
public partial class _Default : System.Web.UI.Page
{
    String sql = String.Empty; 
 
    protected void Page_Load(object sender, EventArgs e)
    {
        //Default SQL statement which will be executed when no search conditions were entered
        sql = "SELECT tblSecurity.Username, tblSecurity.First_Name, tblSecurity.Last_Name, tblSecurity.Company_number FROM tblSecurity";
        //Connection string - @@DBName will be replaced by the server name selected from the
        //Environment dropdown
        String connString = "DATA SOURCE = Labsdirvg600;Initial Catalog=TimeEntry;User ID=Labswirvg600;Password=Kling0n1";
        //A boolean field which is used to add a WHERE clause to the SQL statement
        //Boolean whereClauseAdded = false;
 
        //Connection string is formed here. cboEnvironment.SelectedItem.Value will return
        //the selected environment.
        //connString = connString.Replace("@@DBName", cboEnvironment.SelectedItem.Value);
    }
 
    protected void btnSubmit_Click(object sender, EventArgs e)
    {
        if (query.Checked)
            sql = "SELECT * from tblSecurity where Username Like '%sm'";
        if (query.Checked)
 
            sql = "SELECT * from tblSecurity where Username Like '%jo'";
 
 
        //Set the connection string of the SQLDataSource here
        dsToolkit.ConnectionString = connString;
 
        //Atleast one search criteria must be entered by the user if a WHERE clause needs to be
        //added
 
        //Now, the dynamically created SQL statement needs to be assigned to the SQL Data source
        dsToolkit.SelectCommand = sql;
 
        //Finally, refresh the Grid, which will cause the data source to execute the above created
        //SQL and show the results in the grid
        grdPayroll.DataBind();
    }
 
}

Open in new window

0

Featured Post

Space-Age Communications Transitions to DevOps

ViaSat, a global provider of satellite and wireless communications, securely connects businesses, governments, and organizations to the Internet. Learn how ViaSat’s Network Solutions Engineer, drove the transition from a traditional network support to a DevOps-centric model.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Update (December 2011): Since this article was published, the things have changed for good for Android native developers. The Sequoyah Project (http://www.eclipse.org/sequoyah/) automates most of the tasks discussed in this article. You can even fin…
A long time ago (May 2011), I have written an article showing you how to create a DLL using Visual Studio 2005 to be hosted in SQL Server 2005. That was valid at that time and it is still valid if you are still using these versions. You can still re…
THe viewer will learn how to use NetBeans IDE 8.0 for Windows to perform CRUD operations on a MySql database.
The viewer will learn how to use and create new code templates in NetBeans IDE 8.0 for Windows.

730 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question