/**
* @param kind
* @param ancestor
* @return
*/
public static Iterable<Entity> listChildKeys(String kind, Key ancestor) {
logger.log(Level.INFO, "Search entities based on parent");
Query q = new Query(kind);
q.setAncestor(ancestor).setKeysOnly();
q.addFilter(Entity.KEY_RESERVED_PROPERTY, FilterOperator.GREATER_THAN, ancestor);
PreparedQuery pq = datastore.prepare(q);
return pq.asIterable();
}
/**
* Counts the rows of the specified table
*
* @param searchIn the kind of entity (table) to search in
* @param parent search for all entities with this parent
* @param filters all properties to search for
* @return number of rows
*/
public static int count(String searchIn, Key parent, FilterWrapper... filters) {
Query query = new Query(searchIn);
query.setKeysOnly();
if (parent != null) {
query.setAncestor(parent);
}
setFilterProperties(query, filters);
PreparedQuery preparedQuery = mDatastore.prepare(query);
return preparedQuery.countEntities(FetchOptions.Builder.withDefaults());
}
/**
* Get all entities with the specified parent and properties
*
* @param searchIn what kind of entity (table) to search in
* @param parent search for all entities with this parent
* @param filters all properties to search for
* @return an iterable of all found entities with the specified parent
*/
public static Iterable<Entity> getEntities(
String searchIn, Key parent, FilterWrapper... filters) {
Query query = new Query(searchIn);
// Parent
if (parent != null) {
query.setAncestor(parent);
}
setFilterProperties(query, filters);
PreparedQuery preparedQuery = mDatastore.prepare(query);
return preparedQuery.asIterable();
}
/** Google issueId:1458158 */
@Test
public void testIntFilter() {
Query q = new Query(kindName);
Query.Filter filter =
Query.CompositeFilterOperator.and(
new FilterPredicate("intData1", Query.FilterOperator.LESS_THAN, 20),
new FilterPredicate("intData1", Query.FilterOperator.GREATER_THAN, 1),
new FilterPredicate("intData1", Query.FilterOperator.EQUAL, null));
q.setFilter(filter);
q.addSort("intData1", Query.SortDirection.ASCENDING);
q.setAncestor(rootKey);
assertEquals(1, service.prepare(q).countEntities(fo));
List<Entity> elist = service.prepare(q).asList(fo);
assertEquals(Arrays.asList(1L, 10L, null), elist.get(0).getProperty("intData1"));
}
@Test
public void testStrFilter() {
Query q = new Query(kindName);
q.setAncestor(rootKey);
Query.Filter filter =
Query.CompositeFilterOperator.and(
new FilterPredicate("stringData", Query.FilterOperator.LESS_THAN, "qqq"),
new FilterPredicate("stringData", Query.FilterOperator.GREATER_THAN, "mmm"));
q.setFilter(filter);
q.addSort("stringData", Query.SortDirection.ASCENDING);
assertEquals(2, service.prepare(q).countEntities(fo));
List<Entity> elist = service.prepare(q).asList(fo);
assertEquals(Arrays.asList("abc", "xyz", "mno"), elist.get(0).getProperty("stringData"));
assertEquals(Arrays.asList("ppp", "iii", "ddd"), elist.get(1).getProperty("stringData"));
}
/**
* Searches for an existing entity
*
* @param searchIn what kind of entity to search in
* @param parent the parent of the entity to find, set to null to skip
* @param onlyKeys will only retrieve keys for the found entity
* @param filters property name and values to search for
* @return found entity, null if none or more than 1 was found
*/
private static Entity getSingleEntity(
String searchIn, Key parent, boolean onlyKeys, FilterWrapper... filters) {
Query query = new Query(searchIn);
if (onlyKeys) {
query.setKeysOnly();
}
setFilterProperties(query, filters);
if (parent != null) {
query.setAncestor(parent);
}
try {
return mDatastore.prepare(query).asSingleEntity();
} catch (TooManyResultsException e) {
// Does nothing
}
return null;
}
/**
* Get all entities (with only keys) with the specified parent and properties
*
* @param searchIn what kind of entity (table) to search in
* @param parent search for all entities with this parent
* @param filters all properties to search for
* @return an array list of all found entities with the specified parent
*/
public static List<Key> getKeys(String searchIn, Key parent, FilterWrapper... filters) {
Query query = new Query(searchIn);
query.setKeysOnly();
// Parent
if (parent != null) {
query.setAncestor(parent);
}
// Search by properties
setFilterProperties(query, filters);
PreparedQuery preparedQuery = mDatastore.prepare(query);
ArrayList<Key> keys = new ArrayList<>();
for (Entity entity : preparedQuery.asIterable()) {
keys.add(entity.getKey());
}
return keys;
}