Beginning LINQ to SQL Using Visual Studio 2008 - CRUD operations using the LINQ to SQL application (without LINQ designer): Source in C#
(Page 6 of 6 )
The following is the source code in C# 2008 for the UI designed in the previous sections:
using System.Data.Linq;
namespace SampleCS
{
public partial class CRUDSample : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
this.lblMsg.Text = string.Empty;
}
protected void btnSearch_Click(object sender, EventArgs e)
{
try
{
DataContext db = new DataContext(new System.Data.SqlClient.SqlConnection("data source=.sql2k5;initial catalog=Sample;user id=sa;Password=eXpress2005"));
//getting table
Table<Emp> tblEmps = db.GetTable<Emp>();
//getting an existing row
Emp objEmp = tblEmps.SingleOrDefault(p => p.empno == Int32.Parse( this.txtEmpno.Text ));
if (objEmp!=null )
{
this.txtEname.Text = objEmp.ename;
this.txtSal.Text = Convert.ToString( objEmp.sal) ;
this.txtDeptno.Text = Convert.ToString(objEmp.deptno) ;
}
else
this.lblMsg.Text = "Employee not found";
}
catch (Exception ex)
{
this.lblMsg.Text = ex.Message;
}
}
protected void btnSelectStar_Click(object sender, EventArgs e)
{
DataContext db = new DataContext(new System.Data.SqlClient.SqlConnection("data source=.sql2k5;initial catalog=Sample;user id=sa;Password=eXpress2005"));
Table<Emp> tblEmps = db.GetTable<Emp>();
this.GridView1.DataSource = tblEmps;
this.GridView1.DataBind();
}
protected void btnInsert_Click(object sender, EventArgs e)
{
try
{
DataContext db = new DataContext(new System.Data.SqlClient.SqlConnection("data source=.sql2k5;initial catalog=Sample;user id=sa;Password=eXpress2005"));
//getting table
Table<Emp> tblEmps = db.GetTable<Emp>();
//adding a new row
Emp rEmp = new Emp {empno = Int32.Parse(this.txtEmpno.Text), ename = this.txtEname.Text, sal = Double.Parse(this.txtSal.Text), deptno = Int32.Parse(this.txtDeptno.Text)};
tblEmps.InsertOnSubmit(rEmp);
//saving rows added
db.SubmitChanges();
this.lblMsg.Text = "Added Successfully";
}
catch (Exception ex)
{
this.lblMsg.Text = ex.Message;
}
}
protected void btnUpdate_Click(object sender, EventArgs e)
{
try
{
DataContext db = new DataContext(new System.Data.SqlClient.SqlConnection("data source=.sql2k5;initial catalog=Sample;user id=sa;Password=eXpress2005"));
//getting table
Table<Emp> tblEmps = db.GetTable<Emp>();
//getting an existing row
Emp objEmp = tblEmps.SingleOrDefault(p => p.empno == Int32.Parse(this.txtEmpno.Text));
if (objEmp != null)
{
//modifying the row
objEmp.ename=this.txtEname.Text ;
objEmp.sal = Double.Parse(this.txtSal.Text);
objEmp.deptno = Int32.Parse(this.txtDeptno.Text);
//saving rows modified
db.SubmitChanges();
this.lblMsg.Text = "Updated Successfully";
}
else
this.lblMsg.Text = "Employee not found";
}
catch (Exception ex)
{
this.lblMsg.Text = ex.Message;
}
}
protected void btnDelete_Click(object sender, EventArgs e)
{
try
{
DataContext db = new DataContext(new System.Data.SqlClient.SqlConnection("data source=.sql2k5;initial catalog=Sample;user id=sa;Password=eXpress2005"));
//getting table
Table<Emp> tblEmps = db.GetTable<Emp>();
//getting an existing row
Emp objEmp = tblEmps.SingleOrDefault(p => p.empno == Int32.Parse(this.txtEmpno.Text));
if (objEmp != null)
{
//delete the row
tblEmps.DeleteOnSubmit(objEmp);
//saving rows modified
db.SubmitChanges();
this.lblMsg.Text = "Deleted Successfully";
}
else
this.lblMsg.Text = "Employee not found";
}
catch (Exception ex)
{
this.lblMsg.Text = ex.Message;
}
}
}
}
My upcoming articles will focus further in-depth on "LINQ to SQL" (including designers). I hope you enjoyed this article and any suggestions, bugs, errors, enhancements etc. are highly appreciated at http://jagchat.spaces.live.com
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