add update statement

update.go

@@ -0,0 +1,126 @@
+package sqimple
+
+import (
+	"slices"
+	"strings"
+)
+
+// https://www.sqlite.org/lang_update.html
+type UpdateStatement struct {
+	table UpdateTable
+	or    string
+
+	columns []string
+	set     map[string]any
+
+	where []Where
+	args  []any
+}
+
+func (s *UpdateStatement) Args() []any {
+	args := []any{}
+
+	for _, column := range s.columns {
+		args = append(args, s.set[column])
+	}
+
+	for _, arg := range s.args {
+		args = append(args, arg)
+	}
+
+	return args
+}
+
+func (s *UpdateStatement) IsValid() bool {
+	if !s.table.IsValid() {
+		return false
+	}
+
+	for _, w := range s.where {
+		if !w.IsValid() {
+			return false
+		}
+	}
+
+	return false
+}
+
+func (s *UpdateStatement) Or(or string) *UpdateStatement {
+	s.or = or
+	return s
+}
+
+func (s *UpdateStatement) Set(column string, value any) *UpdateStatement {
+	if s.columns == nil {
+		s.columns = []string{}
+	}
+
+	if s.set == nil {
+		s.set = map[string]any{}
+	}
+
+	if !slices.Contains(s.columns, column) {
+		s.columns = append(s.columns, column)
+	}
+
+	s.set[column] = value
+
+	return s
+}
+
+func (s *UpdateStatement) SetMap(data map[string]any) *UpdateStatement {
+	for column, value := range data {
+		s.Set(column, value)
+	}
+
+	return s
+}
+
+func (s *UpdateStatement) String() string {
+	strs := []string{"update"}
+
+	if s.or != "" {
+		strs = append(strs, "or", s.or)
+	}
+
+	strs = append(strs, s.table.String(), "set")
+
+	for i, column := range s.columns {
+		if i < len(s.columns)-1 {
+			strs = append(strs, column, "= ?,")
+		} else {
+			strs = append(strs, column, "= ?")
+		}
+	}
+
+	if len(s.where) > 0 {
+		strs = append(strs, "where")
+
+		for _, w := range s.where {
+			strs = append(strs, w.String())
+		}
+	}
+	return strings.Join(strs, " ")
+}
+
+func (s *UpdateStatement) Where(def string, args ...any) *UpdateStatement {
+	s.where = append(s.where, Where(def))
+
+	if len(args) > 0 {
+		if s.args == nil {
+			s.args = []any{}
+		}
+
+		s.args = append(s.args, args...)
+	}
+
+	return s
+}
+
+func Update(table string) *UpdateStatement {
+	s := &UpdateStatement{
+		table: UpdateTable(table),
+	}
+
+	return s
+}