Merge branch 'issue-db-query-changes' into 'master'

Handle execution of queries contain IN clause with empty array

Closes product-iots#885

See merge request entgra/carbon-device-mgt!748

components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/dao/impl/application/GenericApplicationDAOImpl.java

@@ -24,6 +24,7 @@ import org.wso2.carbon.device.application.mgt.common.AppLifecycleState;
 import org.wso2.carbon.device.application.mgt.common.dto.ApplicationDTO;
 import org.wso2.carbon.device.application.mgt.common.dto.CategoryDTO;
 import org.wso2.carbon.device.application.mgt.common.Filter;
+import org.wso2.carbon.device.application.mgt.common.dto.ReviewDTO;
 import org.wso2.carbon.device.application.mgt.common.dto.TagDTO;
 import org.wso2.carbon.device.application.mgt.common.exception.DBConnectionException;
 import org.wso2.carbon.device.application.mgt.core.dao.ApplicationDAO;
@@ -491,6 +492,9 @@ public class GenericApplicationDAOImpl extends AbstractDAOImpl implements Applic
                     + " from the database");
         }
         try {
+            if (packageNames.isEmpty()) {
+                return new ArrayList<>();
+            }
             Connection conn = this.getDBConnection();
             int index = 1;
             StringJoiner joiner = new StringJoiner(",",
@@ -826,9 +830,12 @@ public class GenericApplicationDAOImpl extends AbstractDAOImpl implements Applic
             log.debug("Request received in DAO Layer to get category ids for given category names");
         }
         try {
+            List<Integer> tagIds = new ArrayList<>();
+            if (categoryNames.isEmpty()) {
+                return tagIds;
+            }
             Connection conn = this.getDBConnection();
             int index = 1;
-            List<Integer> tagIds = new ArrayList<>();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT AP_APP_CATEGORY.ID AS ID FROM AP_APP_CATEGORY WHERE AP_APP_CATEGORY.CATEGORY IN (",
                     ") AND TENANT_ID = ?");
@@ -1117,9 +1124,12 @@ public class GenericApplicationDAOImpl extends AbstractDAOImpl implements Applic
             log.debug("Request received in DAO Layer to get tag ids for given tag names");
         }
         try {
+            List<Integer> tagIds = new ArrayList<>();
+            if (tagNames.isEmpty()) {
+                return tagIds;
+            }
             Connection conn = this.getDBConnection();
             int index = 1;
-            List<Integer> tagIds = new ArrayList<>();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT AP_APP_TAG.ID AS ID FROM AP_APP_TAG WHERE AP_APP_TAG.TAG IN (",
                     ") AND TENANT_ID = ?");

components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/dao/impl/application/release/GenericApplicationReleaseDAOImpl.java

@@ -564,6 +564,11 @@ public class GenericApplicationReleaseDAOImpl extends AbstractDAOImpl implements
     public List<ApplicationReleaseDTO> getReleaseByPackages(List<String> packages, int tenantId) throws
             ApplicationManagementDAOException {
 
+        List<ApplicationReleaseDTO> releaseDTOs = new ArrayList<>();
+        if (packages.isEmpty()) {
+            return releaseDTOs;
+        }
+
         String sql = "SELECT "
                 + "AR.ID AS RELEASE_ID, "
                 + "AR.DESCRIPTION AS RELEASE_DESCRIPTION, "
@@ -600,7 +605,6 @@ public class GenericApplicationReleaseDAOImpl extends AbstractDAOImpl implements
                 }
                 statement.setInt(index, tenantId);
                 try (ResultSet resultSet = statement.executeQuery()) {
-                    List<ApplicationReleaseDTO> releaseDTOs = new ArrayList<>();
                     while (resultSet.next()) {
                         releaseDTOs.add(DAOUtil.constructAppReleaseDTO(resultSet));
                     }

components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/dao/impl/review/GenericReviewDAOImpl.java

@@ -110,6 +110,9 @@ public class GenericReviewDAOImpl extends AbstractDAOImpl implements ReviewDAO {
                     + "application. Commenting user: " + username + " and tenant-id: " + tenantId);
         }
         try {
+            if (appReleaseIds.isEmpty()) {
+                return false;
+            }
             Connection conn = this.getDBConnection();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT rv.ID FROM AP_APP_REVIEW rv WHERE rv.AP_APP_RELEASE_ID IN (",
@@ -283,6 +286,9 @@ public class GenericReviewDAOImpl extends AbstractDAOImpl implements ReviewDAO {
             log.debug("DAO request is received to Get all active application reviews.");
         }
         try {
+            if (releaseIds.isEmpty()) {
+                return new ArrayList<>();
+            }
             Connection conn = this.getDBConnection();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT " + "AP_APP_REVIEW.ID AS ID, "
@@ -336,6 +342,9 @@ public class GenericReviewDAOImpl extends AbstractDAOImpl implements ReviewDAO {
             log.debug("DAO request is received to Get all active application reviews of user " + username);
         }
         try {
+            if (releaseIds.isEmpty()) {
+                return new ArrayList<>();
+            }
             Connection conn = this.getDBConnection();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT "
@@ -473,6 +482,10 @@ public class GenericReviewDAOImpl extends AbstractDAOImpl implements ReviewDAO {
             log.debug("DAO request is received to Get all application rating values of an application.");
         }
         try {
+            List<Integer> reviews = new ArrayList<>();
+            if (uuids.isEmpty()) {
+                return reviews;
+            }
             int index = 1;
             Connection conn = this.getDBConnection();
             StringJoiner joiner = new StringJoiner(",",
@@ -487,7 +500,6 @@ public class GenericReviewDAOImpl extends AbstractDAOImpl implements ReviewDAO {
                 }
                 ps.setInt(index, tenantId);
                 try (ResultSet rs = ps.executeQuery()) {
-                    List<Integer> reviews = new ArrayList<>();
                     while (rs.next()) {
                         reviews.add(rs.getInt("RATING"));
                     }

components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/dao/impl/review/OracleReviewDAOImpl.java

@@ -97,6 +97,9 @@ public class OracleReviewDAOImpl extends GenericReviewDAOImpl {
             log.debug("DAO request is received to Get all active application reviews.");
         }
         try {
+            if (releaseIds.isEmpty()) {
+                return new ArrayList<>();
+            }
             Connection conn = this.getDBConnection();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT " + "AP_APP_REVIEW.ID AS ID, "
@@ -150,6 +153,9 @@ public class OracleReviewDAOImpl extends GenericReviewDAOImpl {
             log.debug("DAO request is received to Get all active application reviews of user " + username);
         }
         try {
+            if (releaseIds.isEmpty()) {
+                return new ArrayList<>();
+            }
             Connection conn = this.getDBConnection();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT "
@@ -203,6 +209,10 @@ public class OracleReviewDAOImpl extends GenericReviewDAOImpl {
             log.debug("DAO request is received to Get all application rating values of an application.");
         }
         try {
+            List<Integer> reviews = new ArrayList<>();
+            if (uuids.isEmpty()) {
+                return reviews;
+            }
             int index = 1;
             Connection conn = this.getDBConnection();
             StringJoiner joiner = new StringJoiner(",",
@@ -217,7 +227,6 @@ public class OracleReviewDAOImpl extends GenericReviewDAOImpl {
                 }
                 ps.setInt(index, tenantId);
                 try (ResultSet rs = ps.executeQuery()) {
-                    List<Integer> reviews = new ArrayList<>();
                     while (rs.next()) {
                         reviews.add(rs.getInt("RATING"));
                     }

components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/dao/impl/review/SQLServerReviewDAOImpl.java

@@ -97,6 +97,9 @@ public class SQLServerReviewDAOImpl extends GenericReviewDAOImpl {
             log.debug("DAO request is received to Get all active application reviews.");
         }
         try {
+            if (releaseIds.isEmpty()) {
+                return new ArrayList<>();
+            }
             Connection conn = this.getDBConnection();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT " + "AP_APP_REVIEW.ID AS ID, "
@@ -150,6 +153,9 @@ public class SQLServerReviewDAOImpl extends GenericReviewDAOImpl {
             log.debug("DAO request is received to Get all active application reviews of user " + username);
         }
         try {
+            if (releaseIds.isEmpty()) {
+                return new ArrayList<>();
+            }
             Connection conn = this.getDBConnection();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT "
@@ -203,6 +209,10 @@ public class SQLServerReviewDAOImpl extends GenericReviewDAOImpl {
             log.debug("DAO request is received to Get all application rating values of an application.");
         }
         try {
+            List<Integer> reviews = new ArrayList<>();
+            if (uuids.isEmpty()) {
+                return reviews;
+            }
             int index = 1;
             Connection conn = this.getDBConnection();
             StringJoiner joiner = new StringJoiner(",",
@@ -217,7 +227,6 @@ public class SQLServerReviewDAOImpl extends GenericReviewDAOImpl {
                 }
                 ps.setInt(index, tenantId);
                 try (ResultSet rs = ps.executeQuery()) {
-                    List<Integer> reviews = new ArrayList<>();
                     while (rs.next()) {
                         reviews.add(rs.getInt("RATING"));
                     }

components/application-mgt/org.wso2.carbon.device.application.mgt.core/src/main/java/org/wso2/carbon/device/application/mgt/core/dao/impl/subscription/GenericSubscriptionDAOImpl.java

@@ -383,9 +383,12 @@ public class GenericSubscriptionDAOImpl extends AbstractDAOImpl implements Subsc
             log.debug("Request received in DAO Layer to get device subscriptions for given device ids.");
         }
         try {
+            Map<Integer, DeviceSubscriptionDTO> deviceSubscriptionDTOHashMap = new HashMap<>();
+            if (deviceIds.isEmpty()) {
+                return deviceSubscriptionDTOHashMap;
+            }
             Connection conn = this.getDBConnection();
             int index = 1;
-            Map<Integer, DeviceSubscriptionDTO> deviceSubscriptionDTOHashMap = new HashMap<>();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT "
                             + "DS.ID AS ID, "
@@ -439,9 +442,12 @@ public class GenericSubscriptionDAOImpl extends AbstractDAOImpl implements Subsc
             log.debug("Request received in DAO Layer to get already subscribed users for given list of user names.");
         }
         try {
+            List<String> subscribedUsers = new ArrayList<>();
+            if (users.isEmpty()) {
+                return subscribedUsers;
+            }
             Connection conn = this.getDBConnection();
             int index = 1;
-            List<String> subscribedUsers = new ArrayList<>();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT US.USER_NAME AS USER_NAME "
                             + "FROM AP_USER_SUBSCRIPTION US "
@@ -479,9 +485,12 @@ public class GenericSubscriptionDAOImpl extends AbstractDAOImpl implements Subsc
             log.debug("Request received in DAO Layer to get already subscribed role names for given list of roles.");
         }
         try {
+            List<String> subscribedRoles = new ArrayList<>();
+            if (roles.isEmpty()) {
+                return subscribedRoles;
+            }
             Connection conn = this.getDBConnection();
             int index = 1;
-            List<String> subscribedUsers = new ArrayList<>();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT RS.ROLE_NAME AS ROLE "
                             + "FROM AP_ROLE_SUBSCRIPTION RS "
@@ -496,11 +505,11 @@ public class GenericSubscriptionDAOImpl extends AbstractDAOImpl implements Subsc
                 ps.setInt(index, tenantId);
                 try (ResultSet rs = ps.executeQuery()) {
                     while (rs.next()) {
-                        subscribedUsers.add(rs.getString("ROLE"));
+                        subscribedRoles.add(rs.getString("ROLE"));
                     }
                 }
             }
-            return subscribedUsers;
+            return subscribedRoles;
         } catch (DBConnectionException e) {
             String msg = "Error occurred while obtaining the DB connection to getg subscribed roles for given role "
                     + "names.";
@@ -520,9 +529,12 @@ public class GenericSubscriptionDAOImpl extends AbstractDAOImpl implements Subsc
             log.debug("Request received in DAO Layer to get already subscribed groups for given list of groups.");
         }
         try {
+            List<String> subscribedGroups = new ArrayList<>();
+            if (groups.isEmpty()) {
+                return subscribedGroups;
+            }
             Connection conn = this.getDBConnection();
             int index = 1;
-            List<String> subscribedUsers = new ArrayList<>();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT GS.GROUP_NAME AS GROUP_NAME "
                             + "FROM AP_GROUP_SUBSCRIPTION GS "
@@ -537,11 +549,11 @@ public class GenericSubscriptionDAOImpl extends AbstractDAOImpl implements Subsc
                 ps.setInt(index, tenantId);
                 try (ResultSet rs = ps.executeQuery()) {
                     while (rs.next()) {
-                        subscribedUsers.add(rs.getString("GROUP_NAME"));
+                        subscribedGroups.add(rs.getString("GROUP_NAME"));
                     }
                 }
             }
-            return subscribedUsers;
+            return subscribedGroups;
         } catch (DBConnectionException e) {
             String msg = "Error occurred while obtaining the DB connection to get already subscribed groups for given "
                     + "group names.";
@@ -562,9 +574,12 @@ public class GenericSubscriptionDAOImpl extends AbstractDAOImpl implements Subsc
             log.debug("Request received to DAO Layer to get already subscribed dvice Ids for given list of device Ids.");
         }
         try {
+            List<Integer> subscribedDevices = new ArrayList<>();
+            if (deviceIds.isEmpty()) {
+                return subscribedDevices;
+            }
             Connection conn = this.getDBConnection();
             int index = 1;
-            List<Integer> subscribedDevices = new ArrayList<>();
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT DS.ID AS DEVICE_SUBSCRIPTION_ID "
                             + "FROM AP_DEVICE_SUBSCRIPTION DS "
@@ -695,6 +710,9 @@ public class GenericSubscriptionDAOImpl extends AbstractDAOImpl implements Subsc
     public boolean updateDeviceSubStatus(int deviceId, List<Integer> deviceSubIds, String status, int tenantId)
             throws ApplicationManagementDAOException {
         try {
+            if (deviceSubIds.isEmpty()) {
+                return false;
+            }
             Connection conn = this.getDBConnection();
             int index = 1;
             StringJoiner joiner = new StringJoiner(",",

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/dao/impl/AbstractDeviceDAOImpl.java

@@ -380,6 +380,9 @@ public abstract class AbstractDeviceDAOImpl implements DeviceDAO {
         PreparedStatement stmt = null;
         ResultSet resultSet = null;
         List<Device> devices = new ArrayList<>();
+        if (deviceProps.isEmpty()) {
+            return devices;
+        }
         try {
             List<List<String>> outputLists = new ArrayList<>();
             List<String> deviceList = null;
@@ -935,6 +938,9 @@ public abstract class AbstractDeviceDAOImpl implements DeviceDAO {
             throws DeviceManagementDAOException {
         List<Device> devices = new ArrayList<>();
         try {
+            if (deviceStatuses.isEmpty()) {
+                return devices;
+            }
             Connection conn = this.getConnection();
             StringJoiner joiner = new StringJoiner(",","SELECT "
                     + "e1.OWNER, "
@@ -1222,6 +1228,9 @@ public abstract class AbstractDeviceDAOImpl implements DeviceDAO {
         Connection conn;
         PreparedStatement stmt = null;
         try {
+            if (devices.isEmpty()) {
+                return false;
+            }
             conn = this.getConnection();
             StringBuilder sql = new StringBuilder("UPDATE DM_ENROLMENT SET STATUS = ? WHERE DEVICE_ID IN " +
                     "(SELECT d.ID FROM DM_DEVICE d, DM_DEVICE_TYPE t WHERE d.DEVICE_TYPE_ID = t.ID AND d.DEVICE_IDENTIFICATION IN (");
@@ -1913,6 +1922,10 @@ public abstract class AbstractDeviceDAOImpl implements DeviceDAO {
             int counter = 0;
             List<Device> devices = new ArrayList<>();
 
+            if (deviceIdentifiers.isEmpty()) {
+                return devices;
+            }
+
             StringJoiner joiner = new StringJoiner(",",
                     "SELECT "
                             + "d1.ID AS DEVICE_ID, d1.DESCRIPTION, d1.NAME AS DEVICE_NAME, d1.DEVICE_TYPE, "
@@ -1961,6 +1974,10 @@ public abstract class AbstractDeviceDAOImpl implements DeviceDAO {
             int counter = 0;
             List<Device> devices = new ArrayList<>();
 
+            if (deviceIdentifiers.isEmpty() || statuses.isEmpty()) {
+                return devices;
+            }
+
             StringJoiner statusJoiner = new StringJoiner(",", "e.STATUS IN (", ") ");
             while (counter < statuses.size()) {
                 statusJoiner.add("?");

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/dao/impl/AbstractEventConfigDAO.java

@@ -68,6 +68,9 @@ public abstract class AbstractEventConfigDAO implements EventConfigDAO {
     public List<EventConfig> getEventsOfGroups(List<Integer> groupIds, int tenantId) throws EventManagementDAOException {
         try {
             List<EventConfig> eventList = new ArrayList<>();
+            if (groupIds.isEmpty()) {
+                return eventList;
+            }
             Connection conn = this.getConnection();
             String sql = "SELECT " +
                     "E.ID AS EVENT_ID, " +
@@ -145,6 +148,9 @@ public abstract class AbstractEventConfigDAO implements EventConfigDAO {
     @Override
     public void deleteEventGroupMappingRecordsByEventIds(List<Integer> eventsIdsToDelete) throws EventManagementDAOException {
         try {
+            if (eventsIdsToDelete.isEmpty()) {
+                return;
+            }
             Connection conn = this.getConnection();
             String sql = "DELETE FROM DM_DEVICE_EVENT_GROUP_MAPPING WHERE EVENT_ID IN (%s)";
             String inClause = String.join(", ", Collections.nCopies(eventsIdsToDelete.size(), "?"));
@@ -166,6 +172,9 @@ public abstract class AbstractEventConfigDAO implements EventConfigDAO {
     @Override
     public void deleteEventGroupMappingRecordsByGroupIds(List<Integer> groupIdsToDelete) throws EventManagementDAOException {
         try {
+            if (groupIdsToDelete.isEmpty()) {
+                return;
+            }
             Connection conn = this.getConnection();
             String sql = "DELETE FROM DM_DEVICE_EVENT_GROUP_MAPPING WHERE GROUP_ID IN (%s)";
             String inClause = String.join(", ", Collections.nCopies(groupIdsToDelete.size(), "?"));
@@ -230,6 +239,9 @@ public abstract class AbstractEventConfigDAO implements EventConfigDAO {
     public List<EventConfig> getEventsById(List<Integer> eventIdList) throws EventManagementDAOException {
         try {
             List<EventConfig> eventList = new ArrayList<>();
+            if (eventIdList.isEmpty()) {
+                return eventList;
+            }
             Connection conn = this.getConnection();
             String sql = "SELECT " +
                     "ID AS EVENT_ID, " +
@@ -269,6 +281,9 @@ public abstract class AbstractEventConfigDAO implements EventConfigDAO {
     public List<Integer> getGroupsOfEvents(List<Integer> eventIdList) throws EventManagementDAOException {
         try {
             List<Integer> groupIdList = new ArrayList<>();
+            if (eventIdList.isEmpty()) {
+                return groupIdList;
+            }
             Connection conn = this.getConnection();
             String sql = "SELECT " +
                     "GROUP_ID " +

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/dao/impl/AbstractGroupDAOImpl.java

@@ -772,6 +772,9 @@ public abstract class AbstractGroupDAOImpl implements GroupDAO {
             throws GroupManagementDAOException {
         List<Device> devices = new ArrayList<>();
         try {
+            if (deviceStatuses.isEmpty()) {
+                return devices;
+            }
             Connection conn = GroupManagementDAOFactory.getConnection();
             StringJoiner joiner = new StringJoiner(",","SELECT "
                     + "d1.DEVICE_ID, "

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/dao/impl/GeofenceDAOImpl.java

@@ -421,6 +421,9 @@ public class GeofenceDAOImpl implements GeofenceDAO {
     public Map<Integer, List<EventConfig>> getEventsOfGeoFences(List<Integer> geofenceIds) throws DeviceManagementDAOException {
         try {
             Map<Integer, List<EventConfig>> geoFenceEventMap = new HashMap<>();
+            if (geofenceIds.isEmpty()) {
+                return geoFenceEventMap;
+            }
             Connection conn = this.getConnection();
             String sql = "SELECT " +
                     "E.ID AS EVENT_ID, " +
@@ -490,6 +493,9 @@ public class GeofenceDAOImpl implements GeofenceDAO {
     public Set<GeoFenceGroupMap> getGroupIdsOfGeoFences(List<Integer> fenceIds) throws DeviceManagementDAOException {
         try {
             Set<GeoFenceGroupMap> geoFenceGroupSet = new HashSet<>();
+            if (fenceIds.isEmpty()) {
+                return geoFenceGroupSet;
+            }
             Connection conn = this.getConnection();
             String sql = "SELECT " +
                     "FENCE_ID, " +

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/dao/impl/device/GenericDeviceDAOImpl.java

@@ -883,6 +883,10 @@ public class GenericDeviceDAOImpl extends AbstractDeviceDAOImpl {
         Connection conn;
 
         try {
+            List<Device> devices = new ArrayList<>();
+            if (deviceIds.isEmpty()) {
+                return devices;
+            }
             conn = this.getConnection();
             int index = 1;
 
@@ -937,7 +941,6 @@ public class GenericDeviceDAOImpl extends AbstractDeviceDAOImpl {
                 ps.setInt(index, limitValue);
 
                 try (ResultSet rs = ps.executeQuery()) {
-                    List<Device> devices = new ArrayList<>();
                     while (rs.next()) {
                         devices.add(DeviceManagementDAOUtil.loadDevice(rs));
                     }
@@ -956,6 +959,9 @@ public class GenericDeviceDAOImpl extends AbstractDeviceDAOImpl {
     public int getSubscribedDeviceCount(List<Integer> deviceIds, int tenantId, List<String> status)
             throws DeviceManagementDAOException {
         try {
+            if (deviceIds.isEmpty()) {
+                return 0;
+            }
             Connection conn = this.getConnection();
             int index = 1;
             StringJoiner joiner = new StringJoiner(",",

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/dao/impl/device/OracleDeviceDAOImpl.java

@@ -853,6 +853,10 @@ public class OracleDeviceDAOImpl extends AbstractDeviceDAOImpl {
         Connection conn;
 
         try {
+            List<Device> devices = new ArrayList<>();
+            if (deviceIds.isEmpty()) {
+                return devices;
+            }
             conn = this.getConnection();
             int index = 1;
 
@@ -907,7 +911,6 @@ public class OracleDeviceDAOImpl extends AbstractDeviceDAOImpl {
                 ps.setInt(index, limitValue);
 
                 try (ResultSet rs = ps.executeQuery()) {
-                    List<Device> devices = new ArrayList<>();
                     while (rs.next()) {
                         devices.add(DeviceManagementDAOUtil.loadDevice(rs));
                     }
@@ -926,6 +929,9 @@ public class OracleDeviceDAOImpl extends AbstractDeviceDAOImpl {
     public int getSubscribedDeviceCount(List<Integer> deviceIds, int tenantId, List<String> status)
             throws DeviceManagementDAOException {
         try {
+            if (deviceIds.isEmpty()) {
+                return 0;
+            }
             Connection conn = this.getConnection();
             int index = 1;
             StringJoiner joiner = new StringJoiner(",",

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/dao/impl/device/PostgreSQLDeviceDAOImpl.java

@@ -833,6 +833,10 @@ public class PostgreSQLDeviceDAOImpl extends AbstractDeviceDAOImpl {
         Connection conn;
 
         try {
+            List<Device> devices = new ArrayList<>();
+            if (deviceIds.isEmpty()) {
+                return devices;
+            }
             conn = this.getConnection();
             int index = 1;
 
@@ -887,7 +891,6 @@ public class PostgreSQLDeviceDAOImpl extends AbstractDeviceDAOImpl {
                 ps.setInt(index, limitValue);
 
                 try (ResultSet rs = ps.executeQuery()) {
-                    List<Device> devices = new ArrayList<>();
                     while (rs.next()) {
                         devices.add(DeviceManagementDAOUtil.loadDevice(rs));
                     }
@@ -906,6 +909,9 @@ public class PostgreSQLDeviceDAOImpl extends AbstractDeviceDAOImpl {
     public int getSubscribedDeviceCount(List<Integer> deviceIds, int tenantId, List<String> status)
             throws DeviceManagementDAOException {
         try {
+            if (deviceIds.isEmpty()) {
+                return 0;
+            }
             Connection conn = this.getConnection();
             int index = 1;
             StringJoiner joiner = new StringJoiner(",",

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/dao/impl/device/SQLServerDeviceDAOImpl.java

@@ -699,6 +699,10 @@ public class SQLServerDeviceDAOImpl extends AbstractDeviceDAOImpl {
         Connection conn;
 
         try {
+            List<Device> devices = new ArrayList<>();
+            if (deviceIds.isEmpty()) {
+                return devices;
+            }
             conn = this.getConnection();
             int index = 1;
 
@@ -753,7 +757,6 @@ public class SQLServerDeviceDAOImpl extends AbstractDeviceDAOImpl {
                 ps.setInt(index, limitValue);
 
                 try (ResultSet rs = ps.executeQuery()) {
-                    List<Device> devices = new ArrayList<>();
                     while (rs.next()) {
                         devices.add(DeviceManagementDAOUtil.loadDevice(rs));
                     }
@@ -1039,6 +1042,9 @@ public class SQLServerDeviceDAOImpl extends AbstractDeviceDAOImpl {
     public int getSubscribedDeviceCount(List<Integer> deviceIds, int tenantId, List<String> status)
             throws DeviceManagementDAOException {
         try {
+            if (deviceIds.isEmpty()) {
+                return 0;
+            }
             Connection conn = this.getConnection();
             int index = 1;
             StringJoiner joiner = new StringJoiner(",",