add comments for orm package, done

orm/orm_querym2m.go

@@ -4,6 +4,7 @@ import (
 	"reflect"
 )
 
+// model to model struct
 type queryM2M struct {
 	md  interface{}
 	mi  *modelInfo
@@ -12,6 +13,13 @@ type queryM2M struct {
 	ind reflect.Value
 }
 
+// add models to origin models when creating queryM2M.
+// example:
+// 	m2m := orm.QueryM2M(post,"Tag")
+// 	m2m.Add(&Tag1{},&Tag2{})
+//  for _,tag := range post.Tags{}
+//
+// make sure the relation is defined in post model struct tag.
 func (o *queryM2M) Add(mds ...interface{}) (int64, error) {
 	fi := o.fi
 	mi := fi.relThroughModelInfo
@@ -67,6 +75,7 @@ func (o *queryM2M) Add(mds ...interface{}) (int64, error) {
 	return dbase.InsertValue(orm.db, mi, true, names, values)
 }
 
+// remove models following the origin model relationship
 func (o *queryM2M) Remove(mds ...interface{}) (int64, error) {
 	fi := o.fi
 	qs := o.qs.Filter(fi.reverseFieldInfo.name, o.md)
@@ -78,17 +87,20 @@ func (o *queryM2M) Remove(mds ...interface{}) (int64, error) {
 	return nums, nil
 }
 
+// check model is existed in relationship of origin model
 func (o *queryM2M) Exist(md interface{}) bool {
 	fi := o.fi
 	return o.qs.Filter(fi.reverseFieldInfo.name, o.md).
 		Filter(fi.reverseFieldInfoTwo.name, md).Exist()
 }
 
+// clean all models in related of origin model
 func (o *queryM2M) Clear() (int64, error) {
 	fi := o.fi
 	return o.qs.Filter(fi.reverseFieldInfo.name, o.md).Delete()
 }
 
+// count all related models of origin model
 func (o *queryM2M) Count() (int64, error) {
 	fi := o.fi
 	return o.qs.Filter(fi.reverseFieldInfo.name, o.md).Count()
@@ -96,6 +108,7 @@ func (o *queryM2M) Count() (int64, error) {
 
 var _ QueryM2Mer = new(queryM2M)
 
+// create new M2M queryer.
 func newQueryM2M(md interface{}, o *orm, mi *modelInfo, fi *fieldInfo, ind reflect.Value) QueryM2Mer {
 	qm2m := new(queryM2M)
 	qm2m.md = md