Merge pull request #17 from twharmon/having

Having

go.mod

@@ -6,5 +6,4 @@ require (
 	github.com/DATA-DOG/go-sqlmock v1.4.1
 	github.com/go-sql-driver/mysql v1.5.0
 	github.com/mattn/go-sqlite3 v2.0.3+incompatible
-	google.golang.org/appengine v1.6.5 // indirect
 )

select_query.go

@@ -13,18 +13,26 @@ type where struct {
 	condition   string
 }
 
+type having struct {
+	conjunction string
+	condition   string
+}
+
 // SelectQuery holds information for a select query.
 type SelectQuery struct {
-	db     *DB
-	model  *model
-	fields []string
-	joins  []string
-	wheres []*where
-	args   []interface{}
-	order  string
-	many   bool
-	limit  int64
-	offset int64
+	db         *DB
+	model      *model
+	fields     []string
+	joins      []string
+	wheres     []*where
+	whereArgs  []interface{}
+	havings    []*having
+	havingArgs []interface{}
+	groupBy    string
+	order      string
+	many       bool
+	limit      int64
+	offset     int64
 }
 
 // Join joins another table to this query.
@@ -40,7 +48,18 @@ func (sq *SelectQuery) Where(condition string, args ...interface{}) *SelectQuery
 		condition:   condition,
 	}
 	sq.wheres = append(sq.wheres, w)
-	sq.args = append(sq.args, args...)
+	sq.whereArgs = append(sq.whereArgs, args...)
+	return sq
+}
+
+// Having specifies which rows will be returned.
+func (sq *SelectQuery) Having(condition string, args ...interface{}) *SelectQuery {
+	h := &having{
+		conjunction: " and ",
+		condition:   condition,
+	}
+	sq.havings = append(sq.havings, h)
+	sq.havingArgs = append(sq.havingArgs, args...)
 	return sq
 }
 
@@ -51,7 +70,24 @@ func (sq *SelectQuery) OrWhere(condition string, args ...interface{}) *SelectQue
 		condition:   condition,
 	}
 	sq.wheres = append(sq.wheres, w)
-	sq.args = append(sq.args, args...)
+	sq.whereArgs = append(sq.whereArgs, args...)
+	return sq
+}
+
+// OrHaving specifies which rows will be returned.
+func (sq *SelectQuery) OrHaving(condition string, args ...interface{}) *SelectQuery {
+	h := &having{
+		conjunction: " or ",
+		condition:   condition,
+	}
+	sq.havings = append(sq.havings, h)
+	sq.havingArgs = append(sq.havingArgs, args...)
+	return sq
+}
+
+// GroupBy specifies how to group the results.
+func (sq *SelectQuery) GroupBy(bys ...string) *SelectQuery {
+	sq.groupBy = strings.Join(bys, ", ")
 	return sq
 }
 
@@ -124,7 +160,9 @@ func (sq *SelectQuery) toOne(out interface{}) error {
 	if !e.IsValid() {
 		return errors.New("out must not be a nil pointer")
 	}
-	rows, err := sq.db.db.Query(sq.String(), sq.args...)
+	args := sq.whereArgs
+	args = append(args, sq.havingArgs...)
+	rows, err := sq.db.db.Query(sq.String(), args...)
 	if err != nil {
 		return err
 	}
@@ -150,7 +188,9 @@ func (sq *SelectQuery) toOne(out interface{}) error {
 
 func (sq *SelectQuery) toMany(sliceType reflect.Type, outs interface{}) error {
 	sq.many = true
-	rows, err := sq.db.db.Query(sq.String(), sq.args...)
+	args := sq.whereArgs
+	args = append(args, sq.havingArgs...)
+	rows, err := sq.db.db.Query(sq.String(), args...)
 	if err != nil {
 		return err
 	}
@@ -183,7 +223,9 @@ func (sq *SelectQuery) toMany(sliceType reflect.Type, outs interface{}) error {
 
 func (sq *SelectQuery) toManyValues(sliceType reflect.Type, outs interface{}) error {
 	sq.many = true
-	rows, err := sq.db.db.Query(sq.String(), sq.args...)
+	args := sq.whereArgs
+	args = append(args, sq.havingArgs...)
+	rows, err := sq.db.db.Query(sq.String(), args...)
 	if err != nil {
 		return err
 	}
@@ -237,6 +279,21 @@ func (sq *SelectQuery) String() string {
 		}
 		q.WriteString(where.condition)
 	}
+
+	if sq.groupBy != "" {
+		q.WriteString(" group by ")
+		q.WriteString(sq.groupBy)
+	}
+
+	for i, having := range sq.havings {
+		if i == 0 {
+			q.WriteString(" having ")
+		} else {
+			q.WriteString(having.conjunction)
+		}
+		q.WriteString(having.condition)
+	}
+
 	if sq.order != "" {
 		q.WriteString(" order by ")
 		q.WriteString(sq.order)

select_query_test.go

@@ -36,11 +36,11 @@ func TestSelectQueryMany(t *testing.T) {
 	}
 	check(t, db.Register(T{}))
 	control := []*T{
-		&T{
+		{
 			ID:   5,
 			Name: "foo",
 		},
-		&T{
+		{
 			ID:   6,
 			Name: "bar",
 		},
@@ -67,11 +67,11 @@ func TestSelectQueryManyValues(t *testing.T) {
 	}
 	check(t, db.Register(T{}))
 	control := []T{
-		T{
+		{
 			ID:   5,
 			Name: "foo",
 		},
-		T{
+		{
 			ID:   6,
 			Name: "bar",
 		},
@@ -140,15 +140,15 @@ func TestSelectQueryOffset(t *testing.T) {
 	}
 	check(t, db.Register(T{}))
 	control := []T{
-		T{
+		{
 			ID:   6,
 			Name: "bar",
 		},
-		T{
+		{
 			ID:   7,
 			Name: "baz",
 		},
-		T{
+		{
 			ID:   5,
 			Name: "foo",
 		},