Commonly used Writing Method of LINQ

1. datatable

Datatable dt = UDB. getalluser ();
Datatable dt1 = new datatable ();

Ienumerable <datarow> Q1 = from R in DT. asenumerable ()

Where R. Field <int> ("workshop ID") = convert. toint32 (workshop ID) & R. Field <int> ("isadmin") = 0
Orderby R. Field <int> ("workshop ID") Ascending
Select R;
Dt1 = q1.copytodatatable ();

R. Field <int> ("workshop ID"). Convert. toint32 (R ["workshop ID"])

2. List

List <dic_rela_railline_node> selectget =
(From X in dic_rela_railline_nodes
Where X. sub_line_id = railtracklines [I]. r_id.tostring ()
Orderby X. center_kilo ascending
Select X). tolist ();

Paging Method

Ienumerable <datarow> Q1 = (from R in DT. asenumerable ()

Orderby R. Field <int> ("ID") Ascending
Select R). Skip (startindex-1). Take (pagesize );

Skip and take

 

Use VaR

VaR Q1 = (from R in cus

Orderby R. createtime ascending

Select R). Skip (startindex-1). Take (pagesize );

List <common_user> cus2 = new list <common_user> (); cus2 = q1.tolist ();

 

 

 
VaRQuery =FromLInColor s
Group LNew{L. Color ID} into G
Select New
{

Color id = G. Key. Color ID,
Score = G. sum (O => O. Score)
};
 

 
DoubleQ = dB. menuinfo. Where (P => P. PID = PID). Max (P => P. iorder );