EntityDataAdapterTest added to verify convertValue method

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

@@ -79,7 +79,7 @@ public class EntityDataAdapter {
         return entityData;
     }
 
-    private static String convertValue(Object value) {
+    static String convertValue(Object value) {
         if (value != null) {
             String strVal = value.toString();
             // check number

dao/src/test/java/org/thingsboard/server/dao/sql/query/EntityDataAdapterTest.java

@@ -0,0 +1,29 @@
+/**
+ * Copyright © 2016-2021 The Thingsboard Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.thingsboard.server.dao.sql.query;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class EntityDataAdapterTest {
+
+    @Test
+    void testConvertValue() {
+        assertThat(EntityDataAdapter.convertValue("500")).isEqualTo("500");
+        assertThat(EntityDataAdapter.convertValue("500D")).isEqualTo("500D"); //do not convert to Double !!!
+    }
+}