TSK-732: Refactored BaseQuery.listValues method to use Enum instead of String

lib/taskana-core/src/main/java/pro/taskana/AbstractWorkbasketAccessItemQuery.java

@@ -7,7 +7,7 @@ package pro.taskana;
  * @param <T> the workbasket access item
  */
 public interface AbstractWorkbasketAccessItemQuery<Q extends AbstractWorkbasketAccessItemQuery<Q, T>, T extends WorkbasketAccessItem>
-    extends BaseQuery<T> {
+    extends BaseQuery<T, AccessItemQueryColumnName> {
 
     /**
      * Add your unique entry id to your query as filter.

lib/taskana-core/src/main/java/pro/taskana/AccessItemQueryColumnName.java

@@ -0,0 +1,24 @@
+package pro.taskana;
+
+/**
+ * Enum containing the column names for @see pro.taskana.mappings.QueryMapper#queryWorkbasketAccessItemColumnValues(WorkbasketAccessItemQuery).
+ *
+ * @author jsa
+ */
+public enum AccessItemQueryColumnName implements QueryColumnName {
+
+    ID("id"),
+    WORKBASKET_ID("workbasket_id"),
+    WORKBASKET_KEY("wb.key"),
+    ACCESS_ID("access_id");
+
+    private String name;
+    AccessItemQueryColumnName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+}

lib/taskana-core/src/main/java/pro/taskana/BaseQuery.java

@@ -8,8 +8,10 @@ import java.util.List;
  * @author EH
  * @param <T>
  *            specifies the return type of the follwing methods
+ * @param <U>
+ *            specifies the type of the enum used
  */
-public interface BaseQuery<T> {
+public interface BaseQuery<T, U extends Enum<U> & QueryColumnName> {
 
     /**
      * This method will return a list of defined {@link T} objects. In case of a TaskQuery, this method can throw a
@@ -44,7 +46,7 @@ public interface BaseQuery<T> {
      *            the result is sorted in ascending order
      * @return a list of all existing values.
      */
-    List<String> listValues(String dbColumnName, SortDirection sortDirection);
+    List<String> listValues(U dbColumnName, SortDirection sortDirection);
 
     /**
      * This method will return all results for page X with a size of Y of the current query.<br>

lib/taskana-core/src/main/java/pro/taskana/ClassificationQuery.java

@@ -5,7 +5,7 @@ import pro.taskana.exceptions.InvalidArgumentException;
 /**
  * ClassificationQuery for generating dynamic sql.
  */
-public interface ClassificationQuery extends BaseQuery<ClassificationSummary> {
+public interface ClassificationQuery extends BaseQuery<ClassificationSummary, ClassificationQueryColumnName> {
 
     /**
      * Add your key to your query.
@@ -299,4 +299,5 @@ public interface ClassificationQuery extends BaseQuery<ClassificationSummary> {
      *            when the number of the custom is incorrect.
      */
     ClassificationQuery orderByCustomAttribute(String num, SortDirection sortDirection) throws InvalidArgumentException;
+
 }

lib/taskana-core/src/main/java/pro/taskana/ClassificationQueryColumnName.java

@@ -0,0 +1,42 @@
+package pro.taskana;
+
+/**
+ * Enum containing the column names for @see pro.taskana.mappings.QueryMapper#queryClassificationColumnValues(pro.taskana.impl.ClassificationQueryImpl).
+ *
+ * @author jsa
+ */
+public enum ClassificationQueryColumnName implements QueryColumnName {
+    ID("id"),
+    KEY("key"),
+    PARENT_ID("parent_id"),
+    PARENT_KEY("parent_key"),
+    CATEGORY("category"),
+    TYPE("type"),
+    DOMAIN("domain"),
+    VALID_IN_DOMAIN("valid_in_domain"),
+    CREATED("created"),
+    MODIFIED("modified"),
+    NAME("name"),
+    DESCRIPTION("description"),
+    PRIORITY("priority"),
+    SERVICELEVEL("serviceLevel"),
+    APPLICATION_ENTRY_POINT("application_entry_point"),
+    CUSTOM_1("custom_1"),
+    CUSTOM_2("custom_2"),
+    CUSTOM_3("custom_3"),
+    CUSTOM_4("custom_4"),
+    CUSTOM_5("custom_5"),
+    CUSTOM_6("custom_6"),
+    CUSTOM_7("custom_7"),
+    CUSTOM_8("custom_8");
+
+    private String name;
+    ClassificationQueryColumnName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+}

lib/taskana-core/src/main/java/pro/taskana/ObjectReferenceQuery.java

@@ -3,7 +3,7 @@ package pro.taskana;
 /**
  * ObjectReferenceQuery for generating dynamic sql.
  */
-public interface ObjectReferenceQuery extends BaseQuery<ObjectReference> {
+public interface ObjectReferenceQuery extends BaseQuery<ObjectReference, ObjectReferenceQueryColumnName> {
 
     /**
      * Add your company to your query.

lib/taskana-core/src/main/java/pro/taskana/ObjectReferenceQueryColumnName.java

@@ -0,0 +1,26 @@
+package pro.taskana;
+
+/**
+ * Enum containing the column names for @see {@link pro.taskana.mappings.QueryMapper#queryObjectReferenceColumnValues(pro.taskana.impl.ObjectReferenceQueryImpl)}.
+ *
+ * @author jsa
+ */
+public enum ObjectReferenceQueryColumnName implements QueryColumnName {
+    ID("id"),
+    COMPANY("company"),
+    SYSTEM("system"),
+    SYSTEM_INSTANCE("system_instance"),
+    TYPE("type"),
+    VALUE("value");
+
+    private String name;
+    ObjectReferenceQueryColumnName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+}
+

lib/taskana-core/src/main/java/pro/taskana/QueryColumnName.java

@@ -0,0 +1,9 @@
+package pro.taskana;
+
+/**
+ * This interface ist used to emulate an extensible enum for use in the Basequery interface.
+ *
+ * @author jsa
+ */
+public interface QueryColumnName {
+}

lib/taskana-core/src/main/java/pro/taskana/TaskQuery.java

@@ -5,7 +5,7 @@ import pro.taskana.exceptions.InvalidArgumentException;
 /**
  * TaskQuery for generating dynamic sql.
  */
-public interface TaskQuery extends BaseQuery<TaskSummary> {
+public interface TaskQuery extends BaseQuery<TaskSummary, TaskQueryColumnName> {
 
     /**
      * Add your names to your query.

lib/taskana-core/src/main/java/pro/taskana/TaskQueryColumnName.java

@@ -0,0 +1,70 @@
+package pro.taskana;
+
+/**
+ * Enum containing the column names for @see pro.taskana.mappings.QueryMapper#queryTaskColumnValues(pro.taskana.impl.TaskQueryImpl).
+ *
+ * @author jsa
+ */
+public enum TaskQueryColumnName implements QueryColumnName {
+    ID("t.id"),
+    CREATED("t.created"),
+    CLAIMED("t.claimed"),
+    COMPLETED("t.completed"),
+    MODIFIED("t.modified"),
+    PLANNED("t.planned"),
+    DUE("t.due"),
+    NAME("t.name"),
+    CREATOR("t.creator"),
+    DESCRIPTION("t.description"),
+    NOTE("t.note"),
+    PRIORITY("t.priority"),
+    STATE("t.state"),
+    CLASSIFICATION_CATEGORY("t.classification_category"),
+    CLASSIFICATION_KEY("t.classification_key"),
+    CLASSIFICATION_ID("t.classification_id"),
+    WORKBASKET_ID("t.workbasket_id"),
+    WORKBASKET_KEY("t.workbasket_key"),
+    DOMAIN("t.domain"),
+    BUSINESS_PROCESS_ID("t.business_process_id"),
+    PARENT_BUSINESS_PROCESS_ID("t.parent_business_process_id"),
+    OWNER("t.owner"),
+    POR_COMPANY("t.por_company"),
+    POR_SYSTEM("t.por_system"),
+    POR_INSTANCE("t.por_instance"),
+    POR_TYPE("t.por_type"),
+    POR_VALUE("t.por_value"),
+    IS_READ("t.is_read"),
+    IS_TRANSFERRED("t.is_transferred"),
+    CALLBACK_INFO("t.callback_info"),
+    CUSTOM_ATTRIBUTES("t.custom_attributes"),
+    CUSTOM_1("t.custom_1"),
+    CUSTOM_2("t.custom_2"),
+    CUSTOM_3("t.custom_3"),
+    CUSTOM_4("t.custom_4"),
+    CUSTOM_5("t.custom_5"),
+    CUSTOM_6("t.custom_6"),
+    CUSTOM_7("t.custom_7"),
+    CUSTOM_8("t.custom_8"),
+    CUSTOM_9("t.custom_9"),
+    CUSTOM_10("t.custom_10"),
+    CUSTOM_11("t.custom_11"),
+    CUSTOM_12("t.custom_12"),
+    CUSTOM_13("t.custom_13"),
+    CUSTOM_14("t.custom_14"),
+    CUSTOM_15("t.custom_15"),
+    CUSTOM_16("t.custom_16"),
+    ACLASSIFICATION_KEY("a.classification_key"),
+    ACLASSIFICATION_ID("a.classification_id"),
+    CHANNEL("a.channel"),
+    REF_VALUE("a.ref_value");
+
+    private String name;
+    TaskQueryColumnName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+}

lib/taskana-core/src/main/java/pro/taskana/WorkbasketAccessItemQuery.java

@@ -3,7 +3,7 @@ package pro.taskana;
 /**
  * WorkbasketAccessItemQuery for generating dynamic SQL.
  */
-public interface WorkbasketAccessItemQuery extends BaseQuery<WorkbasketAccessItem> {
+public interface WorkbasketAccessItemQuery extends BaseQuery<WorkbasketAccessItem, AccessItemQueryColumnName> {
 
     /**
      * Add your unique entry id to your query as filter.
@@ -102,4 +102,5 @@ public interface WorkbasketAccessItemQuery extends BaseQuery<WorkbasketAccessIte
      * @return the query
      */
     WorkbasketAccessItemQuery orderById(SortDirection sortDirection);
+
 }

lib/taskana-core/src/main/java/pro/taskana/WorkbasketQuery.java

@@ -6,7 +6,7 @@ import pro.taskana.exceptions.NotAuthorizedException;
 /**
  * WorkitemQuery for generating dynamic sql.
  */
-public interface WorkbasketQuery extends BaseQuery<WorkbasketSummary> {
+public interface WorkbasketQuery extends BaseQuery<WorkbasketSummary, WorkbasketQueryColumnName> {
 
     /**
      * Add your ids to your query. The ids are compared to the ids of workbaskets with the IN operator.

lib/taskana-core/src/main/java/pro/taskana/WorkbasketQueryColumnName.java

@@ -0,0 +1,34 @@
+package pro.taskana;
+
+/**
+ * Enum containing the column names for @see {@link pro.taskana.mappings.QueryMapper#queryWorkbasketColumnValues(pro.taskana.impl.WorkbasketQueryImpl)}.
+ *
+ * @author jsa
+ */
+public enum WorkbasketQueryColumnName implements QueryColumnName {
+
+    OWNER("w.owner"),
+    ID("w.id"),
+    KEY("w.key"),
+    NAME("w.name"),
+    DOMAIN("w.domain"),
+    TYPE("w.type"),
+    CUSTOM_1("w.custom_1"),
+    CUSTOM_2("w.custom_2"),
+    CUSTOM_3("w.custom_3"),
+    CUSTOM_4("w.custom_4"),
+    ORG_LEVEL_1("w.org_level_1"),
+    ORG_LEVEL_2("w.org_level_2"),
+    ORG_LEVEL_3("w.org_level_3"),
+    ORG_LEVEL_4("w.org_level_4");
+
+    private String name;
+    WorkbasketQueryColumnName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+}

lib/taskana-core/src/main/java/pro/taskana/impl/AbstractWorkbasketAccessItemQueryImpl.java

@@ -10,6 +10,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import pro.taskana.AbstractWorkbasketAccessItemQuery;
+import pro.taskana.AccessItemQueryColumnName;
 import pro.taskana.TaskanaEngine;
 import pro.taskana.WorkbasketAccessItem;
 import pro.taskana.exceptions.TaskanaRuntimeException;
@@ -27,7 +28,7 @@ abstract class AbstractWorkbasketAccessItemQueryImpl<Q extends AbstractWorkbaske
     private static final String LINK_TO_COUNTER = "pro.taskana.mappings.QueryMapper.countQueryWorkbasketAccessItems";
 
     private static final Logger LOGGER = LoggerFactory.getLogger(AbstractWorkbasketAccessItemQueryImpl.class);
-    private String columnName;
+    private AccessItemQueryColumnName columnName;
     private String[] accessIdIn;
     private String[] workbasketIdIn;
     private String[] idIn;
@@ -103,14 +104,14 @@ abstract class AbstractWorkbasketAccessItemQueryImpl<Q extends AbstractWorkbaske
     }
 
     @Override
-    public List<String> listValues(String columnName, SortDirection sortDirection) {
+    public List<String> listValues(AccessItemQueryColumnName columnName, SortDirection sortDirection) {
         LOGGER.debug("Entry to listValues(dbColumnName={}) this = {}", columnName, _this());
         List<String> result = null;
         try {
             taskanaEngine.openConnection();
             this.columnName = columnName;
             this.orderBy.clear();
-            this.addOrderCriteria(columnName, sortDirection);
+            this.addOrderCriteria(columnName.toString(), sortDirection);
             result = taskanaEngine.getSqlSession().selectList(getLinkToValueMapper(), _this());
             return result;
         } finally {
@@ -207,7 +208,7 @@ abstract class AbstractWorkbasketAccessItemQueryImpl<Q extends AbstractWorkbaske
         return orderColumns;
     }
 
-    public String getColumnName() {
+    public AccessItemQueryColumnName getColumnName() {
         return columnName;
     }
 

lib/taskana-core/src/main/java/pro/taskana/impl/ClassificationQueryImpl.java

@@ -11,6 +11,7 @@ import org.slf4j.LoggerFactory;
 
 import pro.taskana.ClassificationQuery;
 import pro.taskana.ClassificationSummary;
+import pro.taskana.ClassificationQueryColumnName;
 import pro.taskana.TaskanaEngine;
 import pro.taskana.TimeInterval;
 import pro.taskana.exceptions.InvalidArgumentException;
@@ -29,7 +30,7 @@ public class ClassificationQueryImpl implements ClassificationQuery {
     private static final String LINK_TO_VALUEMAPPER = "pro.taskana.mappings.QueryMapper.queryClassificationColumnValues";
     private static final Logger LOGGER = LoggerFactory.getLogger(ClassificationQueryImpl.class);
     private TaskanaEngineImpl taskanaEngine;
-    private String columnName;
+    private ClassificationQueryColumnName columnName;
     private String[] key;
     private String[] idIn;
     private String[] parentId;
@@ -414,14 +415,14 @@ public class ClassificationQueryImpl implements ClassificationQuery {
     }
 
     @Override
-    public List<String> listValues(String columnName, SortDirection sortDirection) {
+    public List<String> listValues(ClassificationQueryColumnName columnName, SortDirection sortDirection) {
         LOGGER.debug("Entry to listValues(dbColumnName={}) this = {}", columnName, this);
         List<String> result = new ArrayList<>();
         try {
             taskanaEngine.openConnection();
             this.columnName = columnName;
             this.orderBy.clear();
-            this.addOrderCriteria(columnName, sortDirection);
+            this.addOrderCriteria(columnName.toString(), sortDirection);
             result = taskanaEngine.getSqlSession().selectList(LINK_TO_VALUEMAPPER, this);
             return result;
         } finally {
@@ -464,8 +465,8 @@ public class ClassificationQueryImpl implements ClassificationQuery {
 
     private ClassificationQuery addOrderCriteria(String columnName, SortDirection sortDirection) {
         String orderByDirection = " " + (sortDirection == null ? SortDirection.ASCENDING : sortDirection);
-        orderBy.add(columnName + orderByDirection);
+        orderBy.add(columnName.toString() + orderByDirection);
-        orderColumns.add(columnName);
+        orderColumns.add(columnName.toString());
         return this;
     }
 
@@ -605,7 +606,7 @@ public class ClassificationQueryImpl implements ClassificationQuery {
         return custom8Like;
     }
 
-    public String getColumnName() {
+    public ClassificationQueryColumnName getColumnName() {
         return columnName;
     }
 

lib/taskana-core/src/main/java/pro/taskana/impl/ObjectReferenceQueryImpl.java

@@ -11,6 +11,7 @@ import org.slf4j.LoggerFactory;
 
 import pro.taskana.ObjectReference;
 import pro.taskana.ObjectReferenceQuery;
+import pro.taskana.ObjectReferenceQueryColumnName;
 import pro.taskana.TaskanaEngine;
 import pro.taskana.exceptions.TaskanaRuntimeException;
 import pro.taskana.impl.util.LoggerUtils;
@@ -27,7 +28,7 @@ public class ObjectReferenceQueryImpl implements ObjectReferenceQuery {
     private static final String LINK_TO_VALUEMAPPER = "pro.taskana.mappings.QueryMapper.queryObjectReferenceColumnValues";
     private static final Logger LOGGER = LoggerFactory.getLogger(ObjectReferenceQueryImpl.class);
     private TaskanaEngineImpl taskanaEngine;
-    private String columnName;
+    private ObjectReferenceQueryColumnName columnName;
     private String[] company;
     private String[] system;
     private String[] systemInstance;
@@ -89,14 +90,14 @@ public class ObjectReferenceQueryImpl implements ObjectReferenceQuery {
     }
 
     @Override
-    public List<String> listValues(String columnName, SortDirection sortDirection) {
+    public List<String> listValues(ObjectReferenceQueryColumnName columnName, SortDirection sortDirection) {
         LOGGER.debug("Entry to listValues(dbColumnName={}) this = {}", columnName, this);
         List<String> result = new ArrayList<>();
         try {
             taskanaEngine.openConnection();
             this.columnName = columnName;
             this.orderBy.clear();
-            this.addOrderCriteria(columnName, sortDirection);
+            this.addOrderCriteria(columnName.toString(), sortDirection);
             result = taskanaEngine.getSqlSession().selectList(LINK_TO_VALUEMAPPER, this);
             return result;
         } finally {
@@ -192,7 +193,7 @@ public class ObjectReferenceQueryImpl implements ObjectReferenceQuery {
         this.value = value;
     }
 
-    public String getColumnName() {
+    public ObjectReferenceQueryColumnName getColumnName() {
         return columnName;
     }
 

lib/taskana-core/src/main/java/pro/taskana/impl/TaskQueryImpl.java

@@ -13,6 +13,7 @@ import org.slf4j.LoggerFactory;
 import pro.taskana.KeyDomain;
 import pro.taskana.ObjectReferenceQuery;
 import pro.taskana.TaskQuery;
+import pro.taskana.TaskQueryColumnName;
 import pro.taskana.TaskState;
 import pro.taskana.TaskSummary;
 import pro.taskana.TaskanaEngine;
@@ -42,7 +43,7 @@ public class TaskQueryImpl implements TaskQuery {
     private static final Logger LOGGER = LoggerFactory.getLogger(TaskQueryImpl.class);
     private TaskanaEngineImpl taskanaEngine;
     private TaskServiceImpl taskService;
-    private String columnName;
+    private TaskQueryColumnName columnName;
     private String[] nameIn;
     private String[] nameLike;
     private String[] creatorIn;
@@ -908,14 +909,14 @@ public class TaskQueryImpl implements TaskQuery {
     }
 
     @Override
-    public List<String> listValues(String columnName, SortDirection sortDirection) {
+    public List<String> listValues(TaskQueryColumnName columnName, SortDirection sortDirection) {
         LOGGER.debug("Entry to listValues(dbColumnName={}) this = {}", columnName, this);
         List<String> result = new ArrayList<>();
         try {
             taskanaEngine.openConnection();
             this.columnName = columnName;
             this.orderBy.clear();
-            this.addOrderCriteria(columnName, sortDirection);
+            this.addOrderCriteria(columnName.toString(), sortDirection);
             checkOpenAndReadPermissionForSpecifiedWorkbaskets();
             setupAccessIds();
             result = taskanaEngine.getSqlSession().selectList(LINK_TO_VALUEMAPPER, this);
@@ -1372,7 +1373,7 @@ public class TaskQueryImpl implements TaskQuery {
         return workbasketIdIn;
     }
 
-    public String getColumnName() {
+    public TaskQueryColumnName getColumnName() {
         return columnName;
     }
 
@@ -1451,7 +1452,7 @@ public class TaskQueryImpl implements TaskQuery {
     private TaskQuery addOrderCriteria(String columnName, SortDirection sortDirection) {
         String orderByDirection = " " + (sortDirection == null ? SortDirection.ASCENDING : sortDirection);
         orderBy.add(columnName + orderByDirection);
-        orderColumns.add(columnName);
+        orderColumns.add(columnName.toString());
         return this;
     }
 

lib/taskana-core/src/main/java/pro/taskana/impl/WorkbasketAccessItemQueryImpl.java

@@ -9,6 +9,7 @@ import org.apache.ibatis.session.RowBounds;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import pro.taskana.AccessItemQueryColumnName;
 import pro.taskana.TaskanaEngine;
 import pro.taskana.WorkbasketAccessItem;
 import pro.taskana.WorkbasketAccessItemQuery;
@@ -24,7 +25,7 @@ public class WorkbasketAccessItemQueryImpl implements WorkbasketAccessItemQuery
     private static final String LINK_TO_COUNTER = "pro.taskana.mappings.QueryMapper.countQueryWorkbasketAccessItems";
     private static final String LINK_TO_VALUEMAPPER = "pro.taskana.mappings.QueryMapper.queryWorkbasketAccessItemColumnValues";
     private static final Logger LOGGER = LoggerFactory.getLogger(WorkbasketQueryImpl.class);
-    private String columnName;
+    private AccessItemQueryColumnName columnName;
     private String[] accessIdIn;
     private String[] accessIdLike;
     private String[] workbasketIdIn;
@@ -120,14 +121,14 @@ public class WorkbasketAccessItemQueryImpl implements WorkbasketAccessItemQuery
     }
 
     @Override
-    public List<String> listValues(String columnName, SortDirection sortDirection) {
+    public List<String> listValues(AccessItemQueryColumnName columnName, SortDirection sortDirection) {
         LOGGER.debug("Entry to listValues(dbColumnName={}) this = {}", columnName, this);
         List<String> result = null;
         try {
             taskanaEngine.openConnection();
             this.columnName = columnName;
             this.orderBy.clear();
-            this.addOrderCriteria(columnName, sortDirection);
+            this.addOrderCriteria(columnName.toString(), sortDirection);
             result = taskanaEngine.getSqlSession().selectList(LINK_TO_VALUEMAPPER, this);
             return result;
         } finally {
@@ -228,7 +229,7 @@ public class WorkbasketAccessItemQueryImpl implements WorkbasketAccessItemQuery
         return orderColumns;
     }
 
-    public String getColumnName() {
+    public AccessItemQueryColumnName getColumnName() {
         return columnName;
     }
 

lib/taskana-core/src/main/java/pro/taskana/impl/WorkbasketQueryImpl.java

@@ -14,6 +14,7 @@ import pro.taskana.TaskanaRole;
 import pro.taskana.TimeInterval;
 import pro.taskana.WorkbasketPermission;
 import pro.taskana.WorkbasketQuery;
+import pro.taskana.WorkbasketQueryColumnName;
 import pro.taskana.WorkbasketSummary;
 import pro.taskana.WorkbasketType;
 import pro.taskana.configuration.TaskanaEngineConfiguration;
@@ -34,7 +35,7 @@ public class WorkbasketQueryImpl implements WorkbasketQuery {
     private static final String LINK_TO_COUNTER = "pro.taskana.mappings.QueryMapper.countQueryWorkbaskets";
     private static final String LINK_TO_VALUEMAPPER = "pro.taskana.mappings.QueryMapper.queryWorkbasketColumnValues";
     private static final Logger LOGGER = LoggerFactory.getLogger(WorkbasketQueryImpl.class);
-    private String columnName;
+    private WorkbasketQueryColumnName columnName;
     private String[] accessId;
     private String[] idIn;
     private WorkbasketPermission permission;
@@ -395,8 +396,7 @@ public class WorkbasketQueryImpl implements WorkbasketQuery {
         }
     }
 
-    @Override
+    public List<String> listValues(WorkbasketQueryColumnName columnName, SortDirection sortDirection) {
-    public List<String> listValues(String columnName, SortDirection sortDirection) {
         LOGGER.debug("Entry to listValues(dbColumnName={}) this = {}", columnName, this);
         List<String> result = new ArrayList<>();
         try {
@@ -614,7 +614,7 @@ public class WorkbasketQueryImpl implements WorkbasketQuery {
         return orderColumns;
     }
 
-    public String getColumnName() {
+    public WorkbasketQueryColumnName getColumnName() {
         return columnName;
     }
 

lib/taskana-core/src/main/java/pro/taskana/jobs/WorkbasketCleanupJob.java

@@ -10,6 +10,7 @@ import org.slf4j.LoggerFactory;
 import pro.taskana.BaseQuery;
 import pro.taskana.BulkOperationResults;
 import pro.taskana.TaskanaEngine;
+import pro.taskana.WorkbasketQueryColumnName;
 import pro.taskana.exceptions.InvalidArgumentException;
 import pro.taskana.exceptions.NotAuthorizedException;
 import pro.taskana.exceptions.TaskanaException;
@@ -64,7 +65,7 @@ public class WorkbasketCleanupJob extends AbstractTaskanaJob {
         List<String> workbasketList = taskanaEngineImpl.getWorkbasketService()
             .createWorkbasketQuery()
             .markedForDeletion(true)
-            .listValues("ID", BaseQuery.SortDirection.ASCENDING);
+            .listValues(WorkbasketQueryColumnName.ID, BaseQuery.SortDirection.ASCENDING);
 
         return workbasketList;
     }

lib/taskana-core/src/test/java/acceptance/classification/QueryClassificationAccTest.java

@@ -3,6 +3,11 @@ package acceptance.classification;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
+import static pro.taskana.ClassificationQueryColumnName.NAME;
+import static pro.taskana.ClassificationQueryColumnName.TYPE;
+import static pro.taskana.ClassificationQueryColumnName.CREATED;
+import static pro.taskana.ClassificationQueryColumnName.VALID_IN_DOMAIN;
+
 import java.time.Instant;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -39,30 +44,30 @@ public class QueryClassificationAccTest extends AbstractAccTest {
     public void testQueryClassificationValuesForColumnName() {
         ClassificationService classificationService = taskanaEngine.getClassificationService();
         List<String> columnValueList = classificationService.createClassificationQuery()
-            .listValues("NAME", null);
+            .listValues(NAME, null);
         assertNotNull(columnValueList);
         assertEquals(16, columnValueList.size());
 
         columnValueList = classificationService.createClassificationQuery()
-            .listValues("TYPE", null);
+            .listValues(TYPE, null);
         assertNotNull(columnValueList);
         assertEquals(2, columnValueList.size());
 
         columnValueList = classificationService.createClassificationQuery()
             .domainIn("")
-            .listValues("TYPE", null);
+            .listValues(TYPE, null);
         assertNotNull(columnValueList);
         assertEquals(2, columnValueList.size());
 
         columnValueList = classificationService.createClassificationQuery()
             .domainIn("")
-            .listValues("CREATED", null);
+            .listValues(CREATED, null);
         assertNotNull(columnValueList);
 
         columnValueList = classificationService.createClassificationQuery()
             .domainIn("")
             .validInDomainEquals(false)
-            .listValues("VALID_IN_DOMAIN", null);
+            .listValues(VALID_IN_DOMAIN, null);
         assertNotNull(columnValueList);
         assertEquals(1, columnValueList.size());    // all are false in ""
     }

lib/taskana-core/src/test/java/acceptance/objectreference/QueryObjectReferenceAccTest.java

@@ -3,6 +3,9 @@ package acceptance.objectreference;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
+import static pro.taskana.ObjectReferenceQueryColumnName.COMPANY;
+import static pro.taskana.ObjectReferenceQueryColumnName.SYSTEM;
+
 import java.util.List;
 
 import org.junit.Test;
@@ -24,16 +27,16 @@ public class QueryObjectReferenceAccTest extends AbstractAccTest {
     public void testQueryObjectReferenceValuesForColumnName() {
         TaskQuery taskQuery = taskanaEngine.getTaskService().createTaskQuery();
         List<String> columnValues = taskQuery.createObjectReferenceQuery()
-            .listValues("COMPANY", null);
+            .listValues(COMPANY, null);
         assertEquals(3, columnValues.size());
 
         columnValues = taskQuery.createObjectReferenceQuery()
-            .listValues("SYSTEM", null);
+            .listValues(SYSTEM, null);
         assertEquals(3, columnValues.size());
 
         columnValues = taskQuery.createObjectReferenceQuery()
             .systemIn("System1")
-            .listValues("SYSTEM", null);
+            .listValues(SYSTEM, null);
         assertEquals(1, columnValues.size());
     }
 

lib/taskana-core/src/test/java/acceptance/task/QueryTasksAccTest.java

@@ -6,6 +6,13 @@ import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 
+import static pro.taskana.TaskQueryColumnName.OWNER;
+import static pro.taskana.TaskQueryColumnName.STATE;
+import static pro.taskana.TaskQueryColumnName.CHANNEL;
+import static pro.taskana.TaskQueryColumnName.REF_VALUE;
+import static pro.taskana.TaskQueryColumnName.ACLASSIFICATION_ID;
+import static pro.taskana.TaskQueryColumnName.CLASSIFICATION_KEY;
+
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
@@ -61,12 +68,12 @@ public class QueryTasksAccTest extends AbstractAccTest {
         List<String> columnValueList = taskService.createTaskQuery()
             .ownerLike("%user%")
             .orderByOwner(desc)
-            .listValues("OWNER", null);
+            .listValues(OWNER, null);
         assertNotNull(columnValueList);
         assertEquals(3, columnValueList.size());
 
         columnValueList = taskService.createTaskQuery()
-            .listValues("STATE", null);
+            .listValues(STATE, null);
         assertNotNull(columnValueList);
         assertEquals(3, columnValueList.size());
     }
@@ -79,25 +86,25 @@ public class QueryTasksAccTest extends AbstractAccTest {
         TaskService taskService = taskanaEngine.getTaskService();
         List<String> columnValueList = taskService.createTaskQuery()
             .attachmentReferenceValueIn("val4")
-            .listValues("CHANNEL", null);
+            .listValues(CHANNEL, null);
         assertNotNull(columnValueList);
         assertEquals(2, columnValueList.size());
 
         columnValueList = taskService.createTaskQuery()
             .attachmentReferenceValueLike("%")
-            .listValues("REF_VALUE", null);
+            .listValues(REF_VALUE, null);
         assertNotNull(columnValueList);
         assertEquals(6, columnValueList.size());
 
         columnValueList = taskService.createTaskQuery()
             .orderByAttachmentClassificationId(desc)
-            .listValues("a.CLASSIFICATION_ID", null);
+            .listValues(ACLASSIFICATION_ID, null);
         assertNotNull(columnValueList);
         assertEquals(12, columnValueList.size());
 
         columnValueList = taskService.createTaskQuery()
             .orderByClassificationKey(desc)
-            .listValues("t.CLASSIFICATION_KEY", null);
+            .listValues(CLASSIFICATION_KEY, null);
         assertNotNull(columnValueList);
         assertEquals(7, columnValueList.size());
     }

lib/taskana-core/src/test/java/acceptance/workbasket/QueryWorkbasketAccTest.java

@@ -4,6 +4,8 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
+import static pro.taskana.WorkbasketQueryColumnName.NAME;
+
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -94,14 +96,14 @@ public class QueryWorkbasketAccTest extends AbstractAccTest {
     public void testQueryWorkbasketValuesForColumnName() {
         WorkbasketService workbasketService = taskanaEngine.getWorkbasketService();
         List<String> columnValueList = workbasketService.createWorkbasketQuery()
-            .listValues("NAME", null);
+            .listValues(NAME, null);
         assertNotNull(columnValueList);
         assertEquals(10, columnValueList.size());
 
         columnValueList = workbasketService.createWorkbasketQuery()
             .nameLike("%korb%")
             .orderByName(asc)
-            .listValues("NAME", SortDirection.DESCENDING);  // will override
+            .listValues(NAME, SortDirection.DESCENDING);  // will override
         assertNotNull(columnValueList);
         assertEquals(4, columnValueList.size());
     }

lib/taskana-core/src/test/java/acceptance/workbasket/QueryWorkbasketAccessItemsAccTest.java

@@ -5,6 +5,10 @@ import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import static pro.taskana.AccessItemQueryColumnName.WORKBASKET_ID;
+import static pro.taskana.AccessItemQueryColumnName.ACCESS_ID;
+import static pro.taskana.AccessItemQueryColumnName.WORKBASKET_KEY;
+
 import java.util.Arrays;
 import java.util.List;
 
@@ -38,17 +42,17 @@ public class QueryWorkbasketAccessItemsAccTest extends AbstractAccTest {
     public void testQueryWorkbasketAccessItemValuesForColumnName() throws NotAuthorizedException {
         WorkbasketService workbasketService = taskanaEngine.getWorkbasketService();
         List<String> columnValueList = workbasketService.createWorkbasketAccessItemQuery()
-            .listValues("WORKBASKET_ID", null);
+            .listValues(WORKBASKET_ID, null);
         assertNotNull(columnValueList);
         assertEquals(24, columnValueList.size());
 
         columnValueList = workbasketService.createWorkbasketAccessItemQuery()
-            .listValues("ACCESS_ID", null);
+            .listValues(ACCESS_ID, null);
         assertNotNull(columnValueList);
         assertEquals(9, columnValueList.size());
 
         columnValueList = workbasketService.createWorkbasketAccessItemQuery()
-            .listValues("WB.KEY", null);
+            .listValues(WORKBASKET_KEY, null);
         assertNotNull(columnValueList);
         assertEquals(24, columnValueList.size());
 

lib/taskana-core/src/test/java/pro/taskana/impl/TestClassificationQuery.java

@@ -4,6 +4,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 import pro.taskana.ClassificationQuery;
+import pro.taskana.ClassificationQueryColumnName;
 import pro.taskana.ClassificationSummary;
 import pro.taskana.TimeInterval;
 
@@ -196,7 +197,7 @@ public class TestClassificationQuery implements ClassificationQuery {
     }
 
     @Override
-    public List<String> listValues(String dbColumnName, SortDirection sortDirection) {
+    public List<String> listValues(ClassificationQueryColumnName dbColumnName, SortDirection sortDirection) {
         return new ArrayList<>();
     }