In This Topic
In this article we use a model created with the help of Entity Developer
(read more about it in the section Using Entity Developer) or created manualy (read more about it in the
section Creating LinqConnect Classes Manually).
Each database table is represented as a Table collection, accessible
via the GetTable() method using its entity class to identify it. It
is recommended that you declare a strongly typed DataContext instead
of relying on the basic DataContext class and the GetTable()
method. A strongly typed DataContext declares all Table
collections as members of the context.
Note: |
To run samples from this article include the following namespace before your code:
|
Use the following examples for data extracting:
// DataContext takes a connection string
CrmDemoDataContext db = new CrmDemoDataContext();
// Get a typed table to run queries
Table<Company> Companies = db.GetTable<Company>();
// Query for companies from Boston
var BostonCompanies =
from c in Companies
where c.City == "Boston"
select c;
foreach (var comp in BostonCompanies)
Console.WriteLine("id = {0}, City = {1}", comp.CompanyID, comp.City);
' DataContext takes a connection string
Dim db As New CrmDemoDataContext
' Get a typed table to run queries
Dim Companies As Table(Of Company) = db.GetTable(Of Company)()
' Query for companies from Boston
Dim BostonCompanies =
From c in Companies _
Where c.City = "Boston" _
Select c
For Each comp in BostonCompanies
Console.WriteLine("id = {0}, City = {1}", comp.CompanyID, comp.City)
Next
The query for companies from Boston can be expressed in a simpler way:
CrmDemoDataContext db = new CrmDemoDataContext();
var BostonCompanies =
from c in db.Companies
where c.City == "Boston"
select c;
foreach (var comp in q)
Console.WriteLine("id = {0}, City = {1}", comp.CompanyID, comp.City);
Dim db As New CrmDemoDataContext
Dim BostonCompanies =
From c In db.Companies _
Where c.City = "Boston" _
Select c
For Each comp in BostonCompanies
Console.WriteLine("id = {0}, City = {1}", comp.CompanyID, comp.City)
Next
You can read more about LINQ queries in the
Querying Across Relationships topic