.net - Inserting One to Many Entities using dapper -

i have following 2 classes , corresponding db tables. trying insert full object graph (student multiple courses). looking example on how 1 using dapper. id's auto-increment identity fields.

class

public class student {     public int id {get;set;}     public string name {get;set;}     public ienumerable<course> courses {get;set;} } public class course {     public int id {get;set;}     public string name {get;set;} } 

table

student
  id [int] (pk)
  name [varchar(50)]

studentcourse
  studentid [int] (fk)
  courseid [int] (fk)

course
  id [int] (fk)
  name [varchar(50)]

dapper has no general helper solve of ... quite easy wire in trivial case:

student student; // populate student ...   student.id = (int)cnn.query<decimal>(@"insert student(name) values(@name) select scope_identity()", student);  if (student.courses != null && student.courses.count > 0) {    foreach(var course in student.courses)    {       course.id = (int)cnn.query<decimal>(@"insert course(name) values(@name) select scope_identity()", course);    }    cnn.execute(@"insert studentcourse(studentid,courseid)  values(@studentid,@courseid)",     student.courses.select(c => new {studentid = student.id, courseid = c.id})); } 

one interesting note sample dapper able handle ienumerable input param , dispatch multiple commands each member of collection. allows efficient param reuse.

of course, stuff gets bit tricky if portions of graph exist in db.