i want to select data from tblcontacts table using the WHERE...LIKE statement so it'll return values that will begin with a certain letter.

this letter will be entered in a textbox and on btn click will return the info to a listbox...

how can this be done??!

i used the below code to retrieve all info from the db, is the syntax for above similar??

From the sounds of it you want to change your sql statement to look somthing like the following.

sql = "Select * From tblContacts where <fieldName> like '" + textBox1.text.Trim() + "%'"

This assumes of course that you are doing the appropriate validation on the textbox input.

and by validation you mean what exactly? and whats the difference between

SELECT * from tblContacts WHERE FirstName =(""&textbox1.text&"", dbconnection) and

SELECT * from tblContacts WHERE FirstName = ""+textbox1.text.Trim()+"%""??

The only problem with this is it exposes your application to sql injection attack, which is not good.

You want to avoid concatenating SQL whenever possible.

So the solution is to use a parameter like the example below:

SqlConnection conn = null;
SqlCommand cmd = null;
try
{
conn = new SqlConnection( CONNECT + "Pooling=False;" );
conn.Open();

// This code below just creates test table and inserts some test values...
xsql_noerror( conn, "drop table tblTest" );
xsql( conn, "create table tblTest(f1 varchar(255))" );
xsql( conn, "insert into tblTest(f1) values ('aaa')" );
xsql( conn, "insert into tblTest(f1) values ('bbb')" );
xsql( conn, "insert into tblTest(f1) values ('ccc')" );

// This code demos how to use LIKE with parameter (the safe way to avoid concatenation).
cmd = conn.CreateCommand();
cmd.CommandText = "select * from tblTest where f1 like @p1"; // Create parameter @p1
cmd.CommandType = CommandType.Text;
cmd.Parameters.Add("@p1", SqlDbType.VarChar, 255); // Set @p1 to matching type for field f1
cmd.Parameters[0].Value = "a%"; // Set parameter value with % at end for matching.
SqlDataReader dr = cmd.ExecuteReader(); // Fetch our data reader.
while (dr.Read())
{
System.Diagnostics.Debug.WriteLine(dr[0].ToString());
}
dr.Dispose();
cmd.Dispose();
}
catch( SqlException sqlEX )
{
System.Diagnostics.Debug.WriteLine( "sqlEX.Number=" + sqlEX.Number );
System.Diagnostics.Debug.WriteLine( "sqlEX.Message=" + sqlEX.Message );
}
finally
{
conn.Dispose();
}