LINQ
anonymous type
to create an object, you must first define the type of the object it?
var obj = new { name=“niming”,age=10};
obj type, the external type of process Anonymous Type inaccessible
Linq query the basic operation (query keywords)
from clause : a specified range and variable data source
where clause : screening data from a data source in accordance with the expression bool
select clause : the elements specified in the query results has the type or form of expression
group clauses : query results are grouped by key (IGrouping <TKey, TElement>)
into clause : providing an identifier, it can serve as a reference to join, group, or select clause results
Linq query the basic operation (query keywords)
orderby clause : to check out the elements are sorted (ascending / descending)
join clauses : connecting two data sources in accordance with the two conditions specified matching Equals
let clause : generating a variable range of a sub-expression in the query expression is stored query result
Compound from clause : two-table query