Merge pull request #477 from kylemcc/read_or_create

Add a ReadOrCreate method:

@@ -74,6 +74,20 @@ func (o *orm) Read(md interface{}, cols ...string) error {
 	return nil
 }
 
+// Try to read a row from the database, or insert one if it doesn't exist
+func (o *orm) ReadOrCreate(md interface{}, col1 string, cols ...string) (bool, int64, error) {
+	cols = append([]string{col1}, cols...)
+	mi, ind := o.getMiInd(md, true)
+	err := o.alias.DbBaser.Read(o.db, mi, ind, o.alias.TZ, cols)
+	if err == ErrNoRows {
+		// Create
+		id, err := o.Insert(md)
+		return (err == nil), id, err
+	}
+
+	return false, ind.Field(mi.fields.pk.fieldIndex).Int(), err
+}
+
 // insert model data to database
 func (o *orm) Insert(md interface{}) (int64, error) {
 	mi, ind := o.getMiInd(md, true)

@@ -1642,3 +1642,41 @@ func TestTransaction(t *testing.T) {
 	throwFail(t, AssertIs(num, 1))
 
 }
+
+func TestReadOrCreate(t *testing.T) {
+	u := &User{
+		UserName: "Kyle",
+		Email: "kylemcc@gmail.com",
+		Password: "other_pass",
+		Status: 7,
+		IsStaff: false,
+		IsActive: true,
+	}
+
+	created, pk, err := dORM.ReadOrCreate(u, "UserName")
+	throwFail(t, err)
+	throwFail(t, AssertIs(created, true))
+	throwFail(t, AssertIs(u.UserName, "Kyle"))
+	throwFail(t, AssertIs(u.Email, "kylemcc@gmail.com"))
+	throwFail(t, AssertIs(u.Password, "other_pass"))
+	throwFail(t, AssertIs(u.Status, 7))
+	throwFail(t, AssertIs(u.IsStaff, false))
+	throwFail(t, AssertIs(u.IsActive, true))
+	throwFail(t, AssertIs(u.Created.In(DefaultTimeLoc), u.Created.In(DefaultTimeLoc), test_Date))
+	throwFail(t, AssertIs(u.Updated.In(DefaultTimeLoc), u.Updated.In(DefaultTimeLoc), test_DateTime))
+
+	nu := &User{UserName: u.UserName, Email: "someotheremail@gmail.com"}
+	created, pk, err = dORM.ReadOrCreate(nu, "UserName")
+	throwFail(t, err)
+	throwFail(t, AssertIs(created, false))
+	throwFail(t, AssertIs(nu.Id, u.Id))
+	throwFail(t, AssertIs(pk, u.Id))
+	throwFail(t, AssertIs(nu.UserName, u.UserName))
+	throwFail(t, AssertIs(nu.Email, u.Email)) // should contain the value in the table, not the one specified above
+	throwFail(t, AssertIs(nu.Password, u.Password))
+	throwFail(t, AssertIs(nu.Status, u.Status))
+	throwFail(t, AssertIs(nu.IsStaff, u.IsStaff))
+	throwFail(t, AssertIs(nu.IsActive, u.IsActive))
+
+	dORM.Delete(u)
+}

@@ -23,6 +23,7 @@ type Fielder interface {
 // orm struct
 type Ormer interface {
 	Read(interface{}, ...string) error
+	ReadOrCreate(interface{}, string, ...string) (bool, int64, error)
 	Insert(interface{}) (int64, error)
 	InsertMulti(int, interface{}) (int64, error)
 	Update(interface{}, ...string) (int64, error)