How to get the data from table through ID or Name (SQL To LINQ)

How to get the data from table through ID or Name (SQL to LINQ)

The following code snippet shows you how you can query direct to SQL Server and in its comparison how you can query using LINQ and get all data on the basis of ID and Name.

This is the connection string which let you connect to the server:

Data Source = "Your Server Name"

Initial Catalog = "The name of your database"

Integrated Security = "true" for getting your credentials automatic to your current login account in windows, in this way you don't have to use user id and password while establishing connection with SQL server.

public static string conString = @"Data Source =  MOAVIA_OSAMA-PC\SQLEXPRESS;Initial Catalog = MyFirst ; Integrated Security = true";

In SQL we write the following query to select all data from a particular table, here we are selecting data from table Customer which contains ID, Name and Address columns in it.

Query Against ID;

string SQLQuery = "SELECT * FROM Customer WHERE ID = 3"; 

Query Against Name; 

string SQLQuery = "SELECT * FROM Customer WHERE Name = 'Maryam' "; 

Now, we would execute this query and return all table from database to store in table. The following GetDataTable() function execute the query and returns the data in table:

public static DataTable GetDataTable(string query) 

{

SqlConnection SQLCon = new SqlConnection(conString);

SqlCommand cmd = new SqlCommand(query, SQLCon);

DataTable table = new DataTable();

SqlDataAdapter da = new SqlDataAdapter(cmd);

da.Fill(table); // and filling the table against the query

return table;

}      

And showing query result in DataGridView:

dataGridView1.DataSource = GetDataTable(SQLQuery);

In LINQ we'll write the queries like that:

The following is the class generated when you add "Linq to SQL classes" to project, which takes an argument of connection string:

DataClasses1DataContext dc = new DataClasses1DataContext(conString);

Query Against ID; 

var LINQuery =

from Customer c in dc.Customers

where c.ID == 3

select c;

Query Against Name;

var LINQuery =

from Customer c in dc.Customers

where c.Name.Equals("Maryam")

select c;

And showing query result in DataGridView:

dataGridView1.DataSource = LINQuery;