select improvements

select.go

@@ -5,15 +5,22 @@ import (
 	"strings"
 )
 
+// https://www.sqlite.org/lang_select.html
 type SelectQuery struct {
+	distinct bool
+
 	columns []Column
 
-	// (from|join type), table, as, A, operator, B
 	tables []SelectTable
 
 	where []Where
 	args  []any
 
+	// group // TODO
+	// having // TODO
+
+	orderBy []OrderBy
+
 	limit  int
 	offset int
 }
@@ -22,12 +29,6 @@ func (s *SelectQuery) Args() []any {
 	return s.args
 }
 
-func (s *SelectQuery) Column(def string) *SelectQuery {
-	s.columns = append(s.columns, Column(def))
-
-	return s
-}
-
 func (s *SelectQuery) Columns(defs ...string) *SelectQuery {
 	for _, def := range defs {
 		s.columns = append(s.columns, Column(def))
@@ -36,6 +37,12 @@ func (s *SelectQuery) Columns(defs ...string) *SelectQuery {
 	return s
 }
 
+func (s *SelectQuery) Distinct(distinct bool) *SelectQuery {
+	s.distinct = distinct
+
+	return s
+}
+
 func (s *SelectQuery) IsValid() bool {
 	for _, c := range s.columns {
 		if !c.IsValid() {
@@ -83,13 +90,29 @@ func (s *SelectQuery) Offset(limit int) *SelectQuery {
 	return s
 }
 
+func (s *SelectQuery) OrderBy(defs ...string) *SelectQuery {
+	if s.orderBy == nil {
+		s.orderBy = []OrderBy{}
+	}
+
+	for _, def := range defs {
+		s.orderBy = append(s.orderBy, OrderBy(def))
+	}
+
+	return s
+}
+
 func (s *SelectQuery) String() string {
 	strs := []string{"select"}
 
+	if s.distinct {
+		strs = append(strs, "distinct")
+	}
+
 	if len(s.columns) > 0 {
 		for i, column := range s.columns {
 			if i < len(s.columns)-1 {
-				strs = append(strs, fmt.Sprintf("%s,", column.String()))
+				strs = append(strs, fmt.Sprintf("%s,", column))
 			} else {
 				strs = append(strs, column.String())
 			}
@@ -110,9 +133,21 @@ func (s *SelectQuery) String() string {
 		}
 	}
 
+	if len(s.orderBy) > 0 {
+		strs = append(strs, "order by")
+
+		for i, o := range s.orderBy {
+			if i < len(s.orderBy)-1 {
+				strs = append(strs, fmt.Sprintf("%s,", o))
+			} else {
+				strs = append(strs, o.String())
+			}
+		}
+	}
+
 	if s.limit > 0 {
 		if s.offset > 0 {
-			strs = append(strs, fmt.Sprintf("limit %d, %d", s.offset, s.limit))
+			strs = append(strs, fmt.Sprintf("limit %d offset %d", s.offset, s.limit))
 		} else {
 			strs = append(strs, fmt.Sprintf("limit %d", s.limit))
 		}