diff --git a/pkg/expr/exp.go b/pkg/expr/exp.go
index e0b3cef53cbc2352facbe85d810d27fa0a4474ae..e34b00b8e521dd9c915ee0bed9a6d62e1ac98aee 100644
--- a/pkg/expr/exp.go
+++ b/pkg/expr/exp.go
@@ -26,10 +26,6 @@ func LessOrEqualNumber(f string, n int) string {
 	return fmt.Sprintf("%s <= %d", f, n)
 }
 
-func StringContains(str, substr string) string {
-	return fmt.Sprintf("%s contains '%s'", str, substr)
-}
-
 func InStringArray(s string, arr []string) string {
 	arrStr := "'" + strings.Join(arr, "','") + "'"
 	return fmt.Sprintf("%s in [%s]", s, arrStr)