CODEWITHSUNDEEP
c#sqlsql-server
user3037238
user3037238

Reputation: 11

retrieving radioButton value from SQL Server using C#

I'm trying to retrieve a radioButton value from database from SQL Server Compact But my code doesn't work and an error message shows (unable to cast object of type 'System.Data.SqlServerCe Command' to type 'System.IConvertible) at line (genderval = Convert.ToBoolean(gendercmnd);) .. what is wrong? thanks

if (con.State != ConnectionState.Open)
    con.Open();

Boolean genderval = false;
SqlCeCommand gendercmnd = new SqlCeCommand(@"SELECT Gender FROM Std_info WHERE Std_id='" + TextBox1.Text + "'", con);
genderval = Convert.ToBoolean(gendercmnd);
if (genderval == true)
    Convert.ToBoolean(radioButton1.Checked);
else
    Convert.ToBoolean(radioButton2.Checked);  
con.Close();

Upvotes: 1

Views: 3029

Answers (5)

user3037238
user3037238

Reputation: 11

the final solution..! 

//........ retrieving radioButton value ....... 

if (conn.State != ConnectionState.Open) 
      conn.Open(); 
try { 
       Boolean genderval = SqlCeCommand gendercmnd = new SqlCeCommand(@"SELECT Gender FROM Std_Info     WHERE Std_id='" + TextBox1.Text + "'", con); 

genderval = (Boolean)gendercmnd.ExecuteScalar(); 

if (genderval == true) 
    Convert.ToBoolean(radioButton1.Checked=true); 
else 
    Convert.ToBoolean(radioButton2.Checked = true); 
conn.Close(); 
     } 
catch (Exception ex)
     {
          MessageBox.Show(ex.Message);
     }

thank you all for your help

Upvotes: 0

user3014562
user3014562

Reputation:

Try executing the command

genderval = (Boolean)gendercmnd.ExecuteScalar();

Also note that your query should be parameterized. Here is a complete example (using SqlConnection but if you replace the Sql classes with your provider classes it should work for you)

bool genderval;

using (SqlConnection conn = new SqlConnection("youeConnStr"))
{
    conn.Open();
    using (SqlCommand cmd = new SqlCommand("SELECT Gender FROM Std_info WHERE Id = @id", conn))
    {
        int id = Convert.ToInt32(TextBox1.Text);
        cmd.Parameters.Add(new SqlParameter("@id", id));
        genderval = (bool)cmd.ExecuteScalar();
    }
}

Upvotes: 2

Joe Cullinan
Joe Cullinan

Reputation: 562

What you're trying to do is to get a result from the SQL server, and cast it as a boolean.

What you're actually doing is trying to convert your SQL command into a boolean.

What you need to do is actually open the connection to the SQL server and execute your query. But it's a bit more complex than that...

if (con.State != ConnectionState.Open)
   con.Open();

Boolean genderval = false;
SqlCeCommand gendercmnd = new SqlCeCommand(@"SELECT Gender FROM Std_info WHERE Std_id='" + TextBox1.Text + "'", con);

gendercmnd.Connection.Open(); // Open the connection using the gendercmd string.
sqlReader = gendercmnd.ExecuteReader(); // Execute the read, which returns an SqlCEDataReader object that we can use to access the data. 


genderval = Convert.ToBoolean(gendercmndResult);
            if (genderval == true)
                Convert.ToBoolean(radioButton1.Checked);
            else
                Convert.ToBoolean(radioButton2.Checked);  
con.Close();

Now we need to take the value from the reader, and cast that as a boolean. 

if (con.State != ConnectionState.Open)
   con.Open();

Boolean genderval = false;
String gendercmndResult = null;
SqlCeCommand gendercmnd = new SqlCeCommand(@"SELECT Gender FROM Std_info WHERE Std_id='" + TextBox1.Text + "'", con);

gendercmnd.Connection.Open(); // Open the connection using the gendercmd string.
sqlReader = gendercmnd.ExecuteReader(); returns an SqlCEDataReader object that we can use to access the data.

while (sqlReader.Read(){ //While the reader is reading...
    gendercmndResult = (sqlReader.GetString(0)); //Assign the returned value from the SQL server to a string called gendercmndResult
}


genderval = Convert.ToBoolean(gendercmndResult); //Now we can cast the string as a bool
            if (genderval == true)
                Convert.ToBoolean(radioButton1.Checked);
            else
                Convert.ToBoolean(radioButton2.Checked);  
con.Close();

Upvotes: 0

vishakvkt
vishakvkt

Reputation: 864

Are you executing the command against the db and getting results? as that code doesn't look like it is doing it. I think you need to call ExecuteScalar() on the sqlcecommand.

Upvotes: 0

Michael Di Felice
Michael Di Felice

Reputation: 406

Looks as though you haven't actually queried the database yet, but are attempting to convert the actual command rather than the results gathered.

I'm not sure if the same works for SQL Server Compact but you need to either ExecuteNonScalar or Execute the command itself, retrieve the results and then run your comparison on that.

Upvotes: 0

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