Simple example of ef-additions and deletions

Objective:

Data context: Northwindcontext,

Data member objects:

Public class Province () {...}

1, new

Province Province=NewProvince {Provinceid = Guid.NewGuid (), Provinceno ="100000", Provincename ="Beijing" }; using(Northwindcontext db =NewNorthwindcontext ()) {db.                Provinces.add (province); Db.            SaveChanges (); }

2,Modify

Province Province=NewProvince {Provinceid =NewGuid ("f0427980-6cb6-4d5b-91f5-ade3e676dea1"), Provinceno ="100000", Provincename ="Shanghai" }; using(Northwindcontext db =NewNorthwindcontext ()) {db. Entry (province). State=entitystate.modified; Db.            SaveChanges (); }

3, delete

Province Province=NewProvince {Provinceid =NewGuid ("f0427980-6cb6-4d5b-91f5-ade3e676dea1") }; using(Northwindcontext db =NewNorthwindcontext ()) {db.                Provinces.attach (province); Db.                Provinces.remove (province); Db.            SaveChanges (); }

4, query

using(Northwindcontext db =NewNorthwindcontext ()) {                varExpr = fromPinchdb. ProvincesSelectp; foreach(varIteminchexpr) {Console.WriteLine ("{0}-{1}-{2}", item. Provinceid, item. Provinceno, item.                Provincename); }            }

Simple example of ef-additions and deletions