Fetch Last Level Only + Distinct values

dao/src/main/java/org/thingsboard/server/dao/sql/query/DefaultEntityQueryRepository.java

@@ -225,9 +225,9 @@ public class DefaultEntityQueryRepository implements EntityQueryRepository {
             " INNER JOIN related_entities re ON" +
             " r.$in_id = re.$out_id and r.$in_type = re.$out_type and" +
             " relation_type_group = 'COMMON' %s)" +
-            " SELECT re.$out_id entity_id, re.$out_type entity_type, re.lvl lvl" +
+            " SELECT re.$out_id entity_id, re.$out_type entity_type, max(re.lvl) lvl" +
             " from related_entities re" +
-            " %s ) entity";
+            " %s GROUP BY entity_id, entity_type) entity";
     private static final String HIERARCHICAL_TO_QUERY_TEMPLATE = HIERARCHICAL_QUERY_TEMPLATE.replace("$in", "to").replace("$out", "from");
     private static final String HIERARCHICAL_FROM_QUERY_TEMPLATE = HIERARCHICAL_QUERY_TEMPLATE.replace("$in", "from").replace("$out", "to");
 
@@ -457,8 +457,6 @@ public class DefaultEntityQueryRepository implements EntityQueryRepository {
 
     private String entitySearchQuery(QueryContext ctx, EntitySearchQueryFilter entityFilter, EntityType entityType, List<String> types) {
         EntityId rootId = entityFilter.getRootEntity();
-        //TODO: fetch last level only.
-        //TODO: fetch distinct records.
         String lvlFilter = getLvlFilter(entityFilter.getMaxLevel());
         String selectFields = "SELECT tenant_id, customer_id, id, created_time, type, name, additional_info "
                 + (entityType.equals(EntityType.ENTITY_VIEW) ? "" : ", label ")
@@ -470,7 +468,9 @@ public class DefaultEntityQueryRepository implements EntityQueryRepository {
             whereFilter += " re.relation_type = :where_relation_type AND";
         }
         whereFilter += " re." + (entityFilter.getDirection().equals(EntitySearchDirection.FROM) ? "to" : "from") + "_type = :where_entity_type";
-
+        if (entityFilter.isFetchLastLevelOnly()) {
+            whereFilter += " and re.lvl = " + entityFilter.getMaxLevel();
+        }
         from = String.format(from, lvlFilter, whereFilter);
         String query = "( " + selectFields + from + ")";
         if (types != null && !types.isEmpty()) {
@@ -500,7 +500,7 @@ public class DefaultEntityQueryRepository implements EntityQueryRepository {
         ctx.addStringParameter("relation_root_type", rootId.getEntityType().name());
 
         StringBuilder whereFilter = new StringBuilder();
-        ;
+
         boolean noConditions = true;
         if (entityFilter.getFilters() != null && !entityFilter.getFilters().isEmpty()) {
             boolean single = entityFilter.getFilters().size() == 1;
@@ -530,6 +530,9 @@ public class DefaultEntityQueryRepository implements EntityQueryRepository {
                     .append("_type in (:where_entity_types").append(")");
             ctx.addStringListParameter("where_entity_types", Arrays.stream(RELATION_QUERY_ENTITY_TYPES).map(EntityType::name).collect(Collectors.toList()));
         }
+        if (entityFilter.isFetchLastLevelOnly()) {
+            whereFilter.append(" and re.lvl = ").append(entityFilter.getMaxLevel());
+        }
         from = String.format(from, lvlFilter, whereFilter);
         return "( " + selectFields + from + ")";
     }