Related Operations for WEBFORM--LINQ

Linq:lineq to SQ class: Integrated data access class; no difference from ADO;
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Creation of LINQ:
Right-click, add New Item, LinQ to SLQ class, suffix name dbml;
A database corresponds to a database;

LINQ operation:
Query all:
//instantiation
Data0617datacontext con = new Data0617datacontext ();
Public List<uesr>select ()
{
return con. Users.tolist ();
}
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Conditional query:
(exact lookup) Click Query:
//LAMDBA expression (traverse all data)
Public List<uesr>select ( String name)
{
return con. Users.where (R=>r.username==name). ToList ();
}
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Field extension: (for example, national display)
"recreate a partial class"
Public partial class Users
{
//have a primary foreign key relationship,
Public String Nname{get{return Nation1.nationname}}
}
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Additions and deletions of LINQ:
Increase (ADD):
public void Insert (Users)
{
Con. Users.insertonsubmit (U);
Con. SubmitChanges ();
}
Delete:
public void Delete (string Uname)
{
Users uu=con. Users.where (R=>r.username==uname). FirstOrDefault ()
if (uu!=null)
{
Con. Users.deleteonsubmit (UU);
Con. SubmitChanges ();
}
}
Modify:

public void Update (Users u)
{
Users Uuu=con. Users.where (R=>r.username==u.username). FirstOrDefault ()
UuU. Passward=u.passward;
Con. SubmitChanges ();
}

Related Operations for WEBFORM--LINQ