fix(page): move pages back when one is deleted inbetween.

internal/database/svgpagedb.go

@@ -27,6 +27,7 @@ const GETSPECIFICSVGPAGESSQL string = "SELECT * FROM svgpage WHERE id = ?;"
 const DELETESVGPAGESQL string = "DELETE FROM svgpage WHERE id = ? AND page = ?;"
 const DELETEALLSVGPAGESQL string = "DELETE FROM svgpage WHERE id = ?;"
 const COUNTSVGPAGESQL string = "SELECT COUNT(*) FROM svgpage WHERE id = ?;"
+const UPDATEPAGESQL string = "UPDATE svgpage SET page = page - 1 WHERE page > ?;"
 
 func InsertSVGPage(data *svg.TemplatePage) (int, error) {
 	json, err := json.Marshal(data.TemplateKeys)
@@ -86,6 +87,11 @@ func DeleteSVGPage(id string, page int) (bool, error) {
 	if num == 0 {
 		return false, nil
 	}
+
+	if err := movePages(id, page); err != nil {
+		return false, err
+	}
+
 	return true, nil
 }
 
@@ -116,3 +122,8 @@ func GetPageCount(id string) (int, error) {
 
 	return count, nil
 }
+
+func movePages(id string, deletedPage int) error {
+	_, err := database.Exec(UPDATEPAGESQL, deletedPage)
+	return err
+}