3. Example

Summary:

A simple message board can be implemented simply by writing a little bit of code. Shows the convenience and powerful functions of LINQ.

 

Content:

Process:

1. Create a database

2. Create a webapp and attach a database

3. Add the LINQ to SQL classes to automatically complete many tasks.

4. Page Layout

5. Background code

A) *** datacontextctx = new *** datacontext ("connection ");

B) read the data and send it to datasource

Rpt_message.datasource = fromgb in CTX. tbguestbooks orderbygb. posttime

Descending select GB;

Rpt_message.databind ();

C) data modification

Tbguestbook GB = CTX. tbguestbooks. Single (B => B. ID =

New GUID (E. commandargument. tostring ()));

CTX. tbguestbooks. Remove (GB); // expired

CTX. submitchanges ();

D) log records

Streamwriter Sw = newstreamwriter (server. mappath ("log.txt"), true );

CTX. log = Sw;

Sw. Close ();

6. Other knowledge

GB. ID = guid. newguid (); // automatic primary key value ????

 

Download source code here