Structure LINQ --- query expression

IMPORTANT:

• Clause must appear in a certain order
• from clause and select. . . group clause two parts is necessary
• Other clauses are optional
• In the LINQ query expression, select the expression clause in the final.
• As many from the can. . . let. . . where clause

from the clause must

from. . . let. . . The optional where clause

orderby clause is optional

select. . . The group clause must

Follow-up inquiries into the optional part