add IsEmpty

misc.go

 package zdb
 
 import (
+	"errors"
 	"github.com/jackc/pgx/v5"
 	"strings"
 )
 
 var ErrNoRows = pgx.ErrNoRows
 
+func IsEmpty(err error) bool {
+	return errors.Is(err, ErrNoRows)
+}
+
 type Opts interface {
 	Opts() (sql string, args map[string]any)
 }