From b0102f523ff946ef0779aae696c8130db6d971a7 Mon Sep 17 00:00:00 2001
From: Andrii Shvaika <ashvayka@thingsboard.io>
Date: Wed, 5 Aug 2020 15:20:15 +0300
Subject: [PATCH] Complex predicate fix

---
 .../thingsboard/server/dao/sql/query/EntityKeyMapping.java  | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/dao/src/main/java/org/thingsboard/server/dao/sql/query/EntityKeyMapping.java b/dao/src/main/java/org/thingsboard/server/dao/sql/query/EntityKeyMapping.java
index 920573ee4c..221ed472e7 100644
--- a/dao/src/main/java/org/thingsboard/server/dao/sql/query/EntityKeyMapping.java
+++ b/dao/src/main/java/org/thingsboard/server/dao/sql/query/EntityKeyMapping.java
@@ -426,11 +426,15 @@ public class EntityKeyMapping {
 
     private String buildComplexPredicateQuery(QueryContext ctx, String alias, EntityKey key,
                                               ComplexFilterPredicate predicate, EntityFilterType filterType) {
-        return predicate.getPredicates().stream()
+        String result = predicate.getPredicates().stream()
                 .map(keyFilterPredicate -> this.buildPredicateQuery(ctx, alias, key, keyFilterPredicate, filterType))
                 .filter(Objects::nonNull).collect(Collectors.joining(
                         " " + predicate.getOperation().name() + " "
                 ));
+        if (!result.trim().isEmpty()) {
+            result = "( " + result + " )";
+        }
+        return result;
     }
 
     private String buildSimplePredicateQuery(QueryContext ctx, String alias, EntityKey key,