LINQ to SQL Series IV using inner Join,outer join

Let's look at one of the simplest inner joins, inner the corresponding class information from the Join Class table when reading the student table:

Static voidMain (string[] args) {    using(varwriter =NewStreamWriter (Watchsqlpath,false, Encoding.UTF8)) {        using(Dbappdatacontext db =NewDbappdatacontext ()) {db. Log=writer; //INNER JOIN            varquery = fromSinchdb. Students Join Cinchdb. Classes on S.classid equals C.classidwhereC.classid = =1                        Select New{ClassID=S.classid, ClassName=C.classname, Student=New{Name=S.name, ID=S.studentid}}; foreach(varIteminchquery) {Console.WriteLine ("{0} {1} {2}", item. ClassID, item. ClassName, item.            Student.name); }}} console.readline ();}

Especially simple, do not post SQL, continue to see outer join:

Static voidMain (string[] args) {    using(varwriter =NewStreamWriter (Watchsqlpath,false, Encoding.UTF8)) {        using(Dbappdatacontext db =NewDbappdatacontext ()) {db. Log=writer; //Left outer join            varquery = fromSinchdb. Students Join Cinchdb. Classes on S.classid equals C.classid into GC fromGciinchGC. DefaultIfEmpty ()Select New{ClassID=S.classid, ClassName=GCI. ClassName, Student=New{Name=S.name, ID=S.studentid}}; foreach(varIteminchquery) {Console.WriteLine ("{0} {1} {2}", item. ClassID, item. ClassName, item.            Student.name); }}} console.readline ();}

Outer join must have the join table into a new variable GC and then use the GC. DefaultIfEmpty () represents an outer join.

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LINQ to SQL Series IV using inner Join,outer join