LINQ to SQL provides a runtime infrastructure for managing relational data as objects without losing the ability to query. Your application is free to manipulate the objects while LINQ to SQL stays in the background tracking your changes automatically.
Here I have created one small database application with basic operations using c# and I have implemented Linq to sql concept.
Step 1: Create one windows application like this
Step 2: Create a database and table with this structure.
Step 3: Add new dbml file(LINQ to SQL Classses).
Step 4: Add new Data Connection in Server Explorer window.
Step 5: Drag the database tables into dbml file
Once you dragged the tables you can see the classes are created in designer.cs (class file). Each table act as one class and the columns act as properties.
Now you can write the code for buttons
To Add New Record
private void btnAdd_Click(object sender, EventArgs e)
{
//Creating instance of dbml class
Employee_DataClassesDataContext db = new Employee_DataClassesDataContext();
try
{
//Createing instance of table
EmployeeTable employee = new EmployeeTable();
//Assigment of values to columns
employee.Emp_ID = Convert.ToInt32(txtEmpId.Text);
employee.Emp_Name = txtname.Text;
employee.Address = txtAddress.Text;
employee.Contactno = txtContact.Text;
//Adding the instance to the database
db.EmployeeTables.InsertOnSubmit(employee);
db.SubmitChanges();
//To retrieve the employee details from database
List lstEmployee = new List();
lstEmployee = (from emp in db.EmployeeTables
select emp).ToList();
//Bind the data to gridview
dataGridView2.DataSource = lstEmployee;
MessageBox.Show("Employee Details Added Successfully");
}
catch (Exception)
{
MessageBox.Show("Error on adding Employee details");
}
}
To Updated Existing Record
private void btnUpdate_Click(object sender, EventArgs e)
{
//Creating instance of dbml class
Employee_DataClassesDataContext db = new Employee_DataClassesDataContext();
try
{
//Createing instance of table
EmployeeTable employee = new EmployeeTable();
int id = Convert.ToInt32(txtEmpId.Text);
//fetching the record which is going to update
employee = (from emp in db.EmployeeTables
where emp.Emp_ID == id
select emp).SingleOrDefault();
//Assigment of new values
employee.Emp_Name = txtname.Text;
employee.Address = txtAddress.Text;
employee.Contactno = txtContact.Text;
//Updating in database
db.SubmitChanges();
MessageBox.Show("Employee Details Updated Successfully");
}
catch (Exception ex)
{
MessageBox.Show("Error on Updating Employee Details");
}
}
To Delete a Record
private void btnDelete_Click(object sender, EventArgs e)
{
//Creating instance of dbml class
Employee_DataClassesDataContext db = new Employee_DataClassesDataContext();
try
{
//Createing instance of table
EmployeeTable employee = new EmployeeTable();
int id = Convert.ToInt32(txtEmpId.Text);
//fetching the record which is going to update
employee = (from emp in db.EmployeeTables
where emp.Emp_ID == id
select emp).SingleOrDefault();
if (MessageBox.Show("Are you sure to Delete?", "Confirm Box", MessageBoxButtons.YesNo) == DialogResult.Yes)
{
//Delete the record
db.EmployeeTables.DeleteOnSubmit(employee);
//Updating in database
db.SubmitChanges();
}
//To retrieve the employee details from database
List lstEmployee = new List();
lstEmployee = (from emp in db.EmployeeTables
select emp).ToList();
//Bind the data to gridview
dataGridView2.DataSource = lstEmployee;
}
catch (Exception Ex)
{
}
}
Its a simple example i wrote but. LINQ to SQL contains lots of interesting thinks lets see in other article
No comments:
Post a Comment