MongoDBAggregates.group()方法详解与编程实例

本文整理了Java中com.mongodb.client.model.Aggregates.group()方法的一些代码示例，展示了Aggregates.group()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Aggregates.group()方法的具体详情如下：
包路径：com.mongodb.client.model.Aggregates
类名称：Aggregates
方法名：group

Aggregates.group介绍

[英]Creates a $group pipeline stage for the specified filter
[中]为指定的筛选器创建$group pipeline阶段

代码示例

代码示例来源：origin: org.mongodb/mongo-java-driver

/**
* Creates a $group pipeline stage for the specified filter
*
* @param the expression type
* @param id the id expression for the group, which may be null
* @param fieldAccumulators zero or more field accumulator pairs
* @return the $group pipeline stage
* @mongodb.driver.manual reference/operator/aggregation/group/ $group
* @mongodb.driver.manual meta/aggregation-quick-reference/#aggregation-expressions Expressions
*/
public static Bson group(@Nullable final TExpression id, final BsonField... fieldAccumulators) {
return group(id, asList(fieldAccumulators));
}

代码示例来源：origin: T-baby/MongoDB-Plugin

public MongoAggregation group(Bson bson) {
pipeline.add(Aggregates.group(bson));
return this;
}

代码示例来源：origin: com.cybermkd/MongodbPlugin

public MongoAggregation group(Bson bson) {
pipeline.add(Aggregates.group(bson));
return this;
}

代码示例来源：origin: com.cybermkd/MongodbPlugin

public MongoAggregation group(String fieldName, MongoAccumulator accumulator) {
pipeline.add(Aggregates.group(fieldName, accumulator.getAccumulators()));
return this;
}

代码示例来源：origin: T-baby/MongoDB-Plugin

public MongoAggregation group(String fieldName, MongoAccumulator accumulator) {
pipeline.add(Aggregates.group(fieldName, accumulator.getAccumulators()));
return this;
}

代码示例来源：origin: org.mongodb/mongodb-driver-core

/**
* Creates a $group pipeline stage for the specified filter
*
* @param the expression type
* @param id the id expression for the group, which may be null
* @param fieldAccumulators zero or more field accumulator pairs
* @return the $group pipeline stage
* @mongodb.driver.manual reference/operator/aggregation/group/ $group
* @mongodb.driver.manual meta/aggregation-quick-reference/#aggregation-expressions Expressions
*/
public static Bson group(@Nullable final TExpression id, final BsonField... fieldAccumulators) {
return group(id, asList(fieldAccumulators));
}

代码示例来源：origin: org.apache.rya/mongodb.rya

/**
* Add a $group step to filter out redundant solutions.
* @return True if the distinct operation was successfully appended.
*/
public boolean distinct() {
List key = new LinkedList<>();
for (String varName : bindingNames) {
key.add(hashFieldExpr(varName));
}
List reduceOps = new LinkedList<>();
for (String field : FIELDS) {
reduceOps.add(new BsonField(field, new Document("$first", "$" + field)));
}
pipeline.add(Aggregates.group(new Document("$concat", key), reduceOps));
return true;
}

代码示例来源：origin: apache/incubator-rya

/**
* Add a $group step to filter out redundant solutions.
* @return True if the distinct operation was successfully appended.
*/
public boolean distinct() {
final List key = new LinkedList<>();
for (final String varName : bindingNames) {
key.add(hashFieldExpr(varName));
}
final List reduceOps = new LinkedList<>();
for (final String field : FIELDS) {
reduceOps.add(new BsonField(field, new Document("$first", "$" + field)));
}
pipeline.add(Aggregates.group(new Document("$concat", key), reduceOps));
return true;
}

代码示例来源：origin: org.opencb.commons/commons-datastore-mongodb

public static List createGroupBy(Bson query, String groupByField, String idField, boolean count) {
if (groupByField == null || groupByField.isEmpty()) {
return new ArrayList<>();
}
if (groupByField.contains(",")) {
// call to multiple createGroupBy if commas are present
return createGroupBy(query, Arrays.asList(groupByField.split(",")), idField, count);
} else {
Bson match = Aggregates.match(query);
Bson project = Aggregates.project(Projections.include(groupByField, idField));
Bson group;
if (count) {
group = Aggregates.group("$" + groupByField, Accumulators.sum("count", 1));
} else {
group = Aggregates.group("$" + groupByField, Accumulators.addToSet("features", "$" + idField));
}
return Arrays.asList(match, project, group);
}
}

代码示例来源：origin: org.eclipse.ditto/ditto-services-thingsearch-persistence

private static void addCountStage(final Collection pipeline, final boolean isCount) {
if (isCount) {
pipeline.add(group(new BsonDocument(FIELD_ID, BsonNull.VALUE), new BsonField(COUNT_RESULT_NAME,
new BsonDocument(SUM_GROUPING, BSON_INT_1))));
}
}

代码示例来源：origin: eclipse/ditto

private static void addCountStage(final Collection pipeline, final boolean isCount) {
if (isCount) {
pipeline.add(group(new BsonDocument(FIELD_ID, BsonNull.VALUE), new BsonField(COUNT_RESULT_NAME,
new BsonDocument(SUM_GROUPING, BSON_INT_1))));
}
}

代码示例来源：origin: opencb/opencga

private long getDiskUsageByStudy(int studyId) {
List operatiOns= new ArrayList<>();
operations.add(Aggregates.match(Filters.eq(PRIVATE_STUDY_ID, studyId)));
operations.add(Aggregates.group("$" + PRIVATE_STUDY_ID, Accumulators.sum("size", "$diskUsage")));
QueryResult aggregate = dbAdaptorFactory.getCatalogFileDBAdaptor().getCollection()
.aggregate(operations, null);
if (aggregate.getNumResults() == 1) {
Object size = aggregate.getResult().get(0).get("size");
if (size instanceof Integer) {
return ((Integer) size).longValue();
} else if (size instanceof Long) {
return ((Long) size);
} else {
return Long.parseLong(size.toString());
}
} else {
return 0;
}
}

代码示例来源：origin: ysrc/Liudao

/**
* 最大统计
*
* @param collectionName
* @param match
* @param maxField
* @return
*/
public Object max(String collectionName, Document match, String maxField) {
AggregateIterable aggregate = getDB().getCollection(collectionName).aggregate(
Arrays.asList(
match(match)
, group(null, Accumulators.max("_max", "$" + maxField))
)
);
Document first = aggregate.first();
if (first != null) {
return first.get("_max");
}
return null;
}

代码示例来源：origin: ysrc/Liudao

/**
* 平均统计
*
* @param collectionName
* @param match
* @param avgField
* @return
*/
public Double avg(String collectionName, Document match, String avgField) {
AggregateIterable aggregate = getDB().getCollection(collectionName).aggregate(
Arrays.asList(
match(match)
, group(null, Accumulators.avg("_avg", "$" + avgField))
)
);
Document first = aggregate.first();
if (first != null) {
return first.getDouble("_avg");
}
return null;
}

代码示例来源：origin: ysrc/Liudao

/**
* 最小统计
*
* @param collectionName
* @param match
* @param minField
* @return
*/
public Object min(String collectionName, Document match, String minField) {
AggregateIterable aggregate = getDB().getCollection(collectionName).aggregate(
Arrays.asList(
match(match)
, group(null, Accumulators.min("_min", "$" + minField))
)
);
Document first = aggregate.first();
if (first != null) {
return first.get("_min");
}
return null;
}

代码示例来源：origin: ysrc/Liudao

/**
* 获取不一样的记录
*
* @param collectionName
* @param match
* @param distinctField
* @return
*/
public List distinct(String collectionName, Document match, String distinctField) {
AggregateIterable aggregate = getDB().getCollection(collectionName).aggregate(
Arrays.asList(
match(match)
, group(null, addToSet("_array", "$" + distinctField))
)
);
Document first = aggregate.first();
if (first != null) {
return (List) first.get("_array");
}
return null;
}

代码示例来源：origin: ysrc/Liudao

/**
* 最近统计
*
* @param collectionName
* @param match
* @param lastField
* @param sort
* @return
*/
public Object last(String collectionName, Document match, String lastField, Document sort) {
AggregateIterable aggregate = getDB().getCollection(collectionName).aggregate(
Arrays.asList(
match(match)
, sort(sort)
, group(null, Accumulators.last("_last", "$" + lastField))
)
);
Document first = aggregate.first();
if (first != null) {
return first.get("_last");
}
return null;
}

代码示例来源：origin: epam/DLab

private Bson groupCriteria() {
return Aggregates.group(getGroupingFields(
MongoKeyWords.DLAB_USER,
MongoKeyWords.DLAB_ID,
MongoKeyWords.RESOURCE_TYPE,
MongoKeyWords.METER_CATEGORY,
MongoKeyWords.CURRENCY_CODE),
Accumulators.sum(MongoKeyWords.COST, MongoKeyWords.prepend$(MongoKeyWords.COST)),
Accumulators.min(MongoKeyWords.USAGE_FROM, MongoKeyWords.prepend$(MongoKeyWords.USAGE_DAY)),
Accumulators.max(MongoKeyWords.USAGE_TO, MongoKeyWords.prepend$(MongoKeyWords.USAGE_DAY))
);
}

代码示例来源：origin: org.eclipse.ditto/ditto-services-thingsearch-persistence

private static Bson createGroupStage() {
return group(new BsonDocument(FIELD_ID, new BsonString(ID_VARIABLE)),
new BsonField(FIELD_NAMESPACE, createProjectionDocument(FIRST_PROJECTION, NAMESPACE_VARIABLE)),
new BsonField(FIELD_ATTRIBUTES, createProjectionDocument(FIRST_PROJECTION, FIELD_ATTRIBUTES_VARIABLE)),
new BsonField(FIELD_FEATURES, createProjectionDocument(FIRST_PROJECTION, FIELD_FEATURES_VARIABLE)),
new BsonField(FIELD_INTERNAL, createProjectionDocument(PUSH_PROJECTION, FIELD_INTERNAL_VARIABLE)),
new BsonField(FIELD_DELETED, createProjectionDocument(FIRST_PROJECTION, FIELD_DELETED_VARIABLE)),
new BsonField(FIELD_REVISION, createProjectionDocument(FIRST_PROJECTION, FIELD_REVISION_VARIABLE)));
}

代码示例来源：origin: eclipse/ditto

private static Bson createGroupStage() {
return group(new BsonDocument(FIELD_ID, new BsonString(ID_VARIABLE)),
new BsonField(FIELD_NAMESPACE, createProjectionDocument(FIRST_PROJECTION, NAMESPACE_VARIABLE)),
new BsonField(FIELD_ATTRIBUTES, createProjectionDocument(FIRST_PROJECTION, FIELD_ATTRIBUTES_VARIABLE)),
new BsonField(FIELD_FEATURES, createProjectionDocument(FIRST_PROJECTION, FIELD_FEATURES_VARIABLE)),
new BsonField(FIELD_INTERNAL, createProjectionDocument(PUSH_PROJECTION, FIELD_INTERNAL_VARIABLE)),
new BsonField(FIELD_DELETED, createProjectionDocument(FIRST_PROJECTION, FIELD_DELETED_VARIABLE)),
new BsonField(FIELD_DELETED_FLAG, createProjectionDocument(FIRST_PROJECTION, FIELD_DELETED_FLAG_VARIABLE)),
new BsonField(FIELD_REVISION, createProjectionDocument(FIRST_PROJECTION, FIELD_REVISION_VARIABLE)));
}