Merge pull request #29 from twharmon/no-limit

Remove the requirement that selects must specify limit
twharmon · Mar 25, 2022 · 1fad099 · 1fad099
2 parents 38e5de8 + 62939b3
commit 1fad099
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Showing 2 changed files with 86 additions and 42 deletions.
diff --git a/select_query.go b/select_query.go
@@ -147,19 +147,13 @@ func (sq *SelectQuery) Get(out interface{}) error {
 			if el.Kind() != reflect.Struct {
 				break
 			}
-			if sq.limit == 0 {
-				return errors.New("limit must be set and not zero when selecting multiple rows")
-			}
 			var err error
 			sq.model, err = sq.db.getModelOf(el)
 			if err != nil {
 				return err
 			}
 			return sq.toMany(t, out)
 		case reflect.Struct:
-			if sq.limit == 0 {
-				return errors.New("limit must be set and not zero when selecting multiple rows")
-			}
 			var err error
 			sq.model, err = sq.db.getModelOf(el)
 			if err != nil {
@@ -215,7 +209,12 @@ func (sq *SelectQuery) toMany(sliceType reflect.Type, outs interface{}) error {
 		return err
 	}
 	defer rows.Close()
-	newOuts := reflect.MakeSlice(sliceType, int(sq.limit), int(sq.limit))
+	var newOuts reflect.Value
+	if sq.limit == 0 {
+		newOuts = reflect.MakeSlice(sliceType, 8, 8)
+	} else {
+		newOuts = reflect.MakeSlice(sliceType, int(sq.limit), int(sq.limit))
+	}
 	i := 0
 	columns, _ := rows.Columns()
 	fieldCount := len(columns)
@@ -228,6 +227,10 @@ func (sq *SelectQuery) toMany(sliceType reflect.Type, outs interface{}) error {
 	}
 	dests := make([]interface{}, fieldCount)
 	for rows.Next() {
+		if newOuts.Len() == i {
+			newOuts.SetCap(newOuts.Len() * 2)
+			newOuts.SetLen(newOuts.Len() * 2)
+		}
 		newOut := newOuts.Index(i)
 		newOut.Set(reflect.New(sq.model.typ))
 		for j := 0; j < fieldCount; j++ {
@@ -253,7 +256,12 @@ func (sq *SelectQuery) toManyValues(sliceType reflect.Type, outs interface{}) er
 		return err
 	}
 	defer rows.Close()
-	newOuts := reflect.MakeSlice(sliceType, int(sq.limit), int(sq.limit))
+	var newOuts reflect.Value
+	if sq.limit == 0 {
+		newOuts = reflect.MakeSlice(sliceType, 8, 8)
+	} else {
+		newOuts = reflect.MakeSlice(sliceType, int(sq.limit), int(sq.limit))
+	}
 	i := 0
 	columns, _ := rows.Columns()
 	fieldCount := len(columns)
@@ -267,6 +275,10 @@ func (sq *SelectQuery) toManyValues(sliceType reflect.Type, outs interface{}) er
 	dests := make([]interface{}, fieldCount)
 	newOut := newOuts.Index(0)
 	for rows.Next() {
+		if newOuts.Len() == i {
+			newOuts.SetCap(newOuts.Len() * 2)
+			newOuts.SetLen(newOuts.Len() * 2)
+		}
 		newOut = newOuts.Index(i)
 		for j := 0; j < fieldCount; j++ {
 			dests[j] = newOut.Field(fieldIndecies[j]).Addr().Interface()
@@ -324,8 +336,10 @@ func (sq *SelectQuery) String() string {
 		q.WriteString(sq.order)
 	}
 	if sq.many {
-		q.WriteString(" limit ")
-		q.WriteString(strconv.FormatInt(sq.limit, 10))
+		if sq.limit > 0 {
+			q.WriteString(" limit ")
+			q.WriteString(strconv.FormatInt(sq.limit, 10))
+		}
 	} else {
 		q.WriteString(" limit 1")
 	}

diff --git a/select_query_test.go b/select_query_test.go
@@ -47,16 +47,76 @@ func TestSelectQueryMany(t *testing.T) {
 	for _, c := range control {
 		rows.AddRow(c.ID, c.Name)
 	}
-	mock.ExpectQuery(`^select \* from t limit 10$`).WillReturnRows(rows)
+	mock.ExpectQuery(`^select \* from t$`).WillReturnRows(rows)
 	var test []*T
-	check(t, db.Select("*").Limit(10).Get(&test))
+	check(t, db.Select("*").Get(&test))
 	check(t, mock.ExpectationsWereMet())
 	for i := 0; i < len(control); i++ {
 		equals(t, control[i], test[i])
 	}
 }
 
 func TestSelectQueryManyValues(t *testing.T) {
+	db, mock, err := getMockDB()
+	check(t, err)
+	type T struct {
+		ID   int `idx:"primary"`
+		Name string
+	}
+	control := []T{
+		{
+			ID:   5,
+			Name: "foo",
+		},
+		{
+			ID:   6,
+			Name: "bar",
+		},
+	}
+	rows := sqlmock.NewRows([]string{"id", "name"})
+	for _, c := range control {
+		rows.AddRow(c.ID, c.Name)
+	}
+	mock.ExpectQuery(`^select \* from t$`).WillReturnRows(rows)
+	var test []T
+	check(t, db.Select("*").Get(&test))
+	check(t, mock.ExpectationsWereMet())
+	for i := 0; i < len(control); i++ {
+		equals(t, control[i], test[i])
+	}
+}
+
+func TestSelectQueryManyLimit(t *testing.T) {
+	db, mock, err := getMockDB()
+	check(t, err)
+	type T struct {
+		ID   int `idx:"primary"`
+		Name string
+	}
+	control := []*T{
+		{
+			ID:   5,
+			Name: "foo",
+		},
+		{
+			ID:   6,
+			Name: "bar",
+		},
+	}
+	rows := sqlmock.NewRows([]string{"id", "name"})
+	for _, c := range control {
+		rows.AddRow(c.ID, c.Name)
+	}
+	mock.ExpectQuery(`^select \* from t$`).WillReturnRows(rows)
+	var test []*T
+	check(t, db.Select("*").Get(&test))
+	check(t, mock.ExpectationsWereMet())
+	for i := 0; i < len(control); i++ {
+		equals(t, control[i], test[i])
+	}
+}
+
+func TestSelectQueryManyValuesLimit(t *testing.T) {
 	db, mock, err := getMockDB()
 	check(t, err)
 	type T struct {
@@ -227,36 +287,6 @@ func TestSelectQueryErrNotStructOrSlice(t *testing.T) {
 	}
 }
 
-func TestSelectQueryErrLimitZeroManyValues(t *testing.T) {
-	db, _, err := getMockDB()
-	check(t, err)
-	type T struct {
-		ID   int `idx:"primary"`
-		Name string
-	}
-	var test []T
-	if err := db.Select("*").Get(&test); err == nil {
-		t.Fatalf("expected err to be non nil")
-	} else {
-		contains(t, err.Error(), "limit")
-	}
-}
-
-func TestSelectQueryErrLimitZeroMany(t *testing.T) {
-	db, _, err := getMockDB()
-	check(t, err)
-	type T struct {
-		ID   int `idx:"primary"`
-		Name string
-	}
-	var test []*T
-	if err := db.Select("*").Get(&test); err == nil {
-		t.Fatalf("expected err to be non nil")
-	} else {
-		contains(t, err.Error(), "limit")
-	}
-}
-
 func TestSelectQueryCustomColumn(t *testing.T) {
 	db, mock, err := getMockDB()
 	check(t, err)