I will show you the steps to create and use a class file in .NET (C#)
Step 1:
Right Click Project >> Select Add New Item >> Class
Step 2:
Create two functions in your class file.
public DataTable ExecuteSlelectQry(string Query)
{
SqlConnection oSqlCon = new SqlConnection(FunGenerateConnectionString(StrCompanyCOde));
DataTable oSqldt = new DataTable();
try
{
using (SqlDataAdapter oSqlda = new SqlDataAdapter(Query, oSqlCon))
{
if (oSqlCon.State == ConnectionState.Closed)
{
oSqlCon.Open();
}
oSqlda.SelectCommand.CommandTimeout = 0;
oSqlda.Fill(oSqldt);
oSqlCon.Close();
}
}
catch (Exception ex)
{
if (oSqlCon.State == ConnectionState.Open)
{
oSqlCon.Close();
}
}
oSqldt.TableName = "RETURN";
return oSqldt;
}
public bool ExecuteNonSelectQry(string Query)
{
SqlConnection oSqlCon = new SqlConnection(FunGenerateConnectionString(StrCompanyCOde));
try
{
using (SqlCommand cmd = new SqlCommand(Query, oSqlCon))
{
if (oSqlCon.State == ConnectionState.Closed)
{
oSqlCon.Open();
}
cmd.CommandTimeout = 0;
cmd.ExecuteNonQuery();
oSqlCon.Close();
}
return true;
}
catch (Exception ex)
{
if (oSqlCon.State == ConnectionState.Open)
{
oSqlCon.Close();
}
return false;
}
}
Step 3:
Create the object of the class on your code behind page
Class oClsClass = new Class();
Step 4:
Access the class functions 1
Datatable oDT = new datatable
oDT = oClsClass.ExecuteSlelectQry("Select * from Employees")
Access the class functions 2
oClsClass.ExecuteNonSelectQry("Insert into Employees(EmpName) values("Abcd")"