1.引言

mongoTemplate提供了许多的方法，许多的类似的方法，刚开始不知道使用哪一种最好，现在，我把他们整理如下，方便大家选择使用。

2.常用方法

    /**
     * 每个操作带上collectionName， 效率提高许多，并且，防止子类错误操作
     *
     * @param formDataApproval 对象
     * @author leimin
     */
    public void mongoTemplateSample(FormDataApproval formDataApproval) {
        Query query = new Query();
        query.addCriteria(Criteria.where("_id").is(formDataApproval.getId()).and("tenant_id").is(formDataApproval.getTenantId()));

        Update update = new Update();
        update.set("process_id", formDataApproval.getProcessId());

        List<FormDataApproval> list = new ArrayList<>();
        list.add(formDataApproval);

        /**
         * 数据库有，就新增， 没有，就修改
         */
        mongoTemplate.upsert(query, update, FormData.class, "formData");
  
        /**
         * 修改方法
         */
        // 无实际意义，不推荐使用
        mongoTemplate.update(FormDataApproval.class);
        mongoTemplate.updateFirst(query, update, FormDataApproval.class, "formDataApproval");
        mongoTemplate.updateMulti(query, update, FormDataApproval.class, "formDataApproval");
        mongoTemplate.findAndModify(query, update, FormDataApproval.class, "formDataApproval");

        /**
         * 查询方法
         */
        mongoTemplate.find(query, FormDataApproval.class, "formDataApproval");
        mongoTemplate.findOne(query, FormDataApproval.class, "formDataApproval");
        mongoTemplate.findAll(FormDataApproval.class, "formDataApproval");
        mongoTemplate.findById(formDataApproval.getId(), FormDataApproval.class, "formDataApproval");

        /**
         * 删除方法
         */
        mongoTemplate.remove(query, FormDataApproval.class, "formDataApproval");
        mongoTemplate.findAndRemove(query, FormDataApproval.class, "formDataApproval");
        mongoTemplate.findAllAndRemove(query, FormDataApproval.class, "formDataApproval");

        /**
         * 新增方法
         */
        mongoTemplate.save(formDataApproval, "formDataApproval"); // 同upsert()，没有新增，有修改
        mongoTemplate.insert(formDataApproval, "formDataApproval");
        mongoTemplate.insertAll(list);
    }

3.批量修改

    /**
     * 批量修改 formData
     *
     * @param formDataList formDatas
     * @author leimin
     */
    @Override
    public void updateFormDatas(List<FormData> formDataList) {

        if (CollectionUtils.isEmpty(formDataList)) {
            return;
        }

        BulkOperations operations = mongoTemplate.bulkOps(BulkOperations.BulkMode.UNORDERED, Const.COLLECTION_FORM_DATA);
        List<Pair<Query, Update>> list = new ArrayList<>();

        for (FormData formData : formDataList) {

            Query query = new Query();
            query.addCriteria(Criteria.where("_id").is(formData.getId()).and("tenant_id").is(formData.getTenantId()));
            Update update = new Update();
            update = mongoUtil.getUpdateFormDataAll(formData, update);
            Pair<Query, Update> pair = Pair.of(query, update);
            list.add(pair);
        }

        operations.updateMulti(list);
        operations.execute();
    }

4.其他方法

    /**
     * 类似于mongo原生sql的操作
     * 不推荐使用
     *
     * @author leimin
     */
    public void mongoTempalteAsOriginal() {

        // 查询该集合中的所有文档
        MongoCollection<Document> formDataApprovalDocument = mongoTemplate.getCollection("formDataApproval");

        // 新增
        formDataApprovalDocument.insertOne();
        formDataApprovalDocument.insertMany();

        // 删除
        formDataApprovalDocument.deleteOne();
        formDataApprovalDocument.deleteMany();
        formDataApprovalDocument.findOneAndDelete();

        // 修改
        formDataApprovalDocument.updateOne();
        formDataApprovalDocument.updateMany();
        formDataApprovalDocument.findOneAndUpdate();
        formDataApprovalDocument.replaceOne();
        formDataApprovalDocument.findOneAndReplace();

        // 查询
        formDataApprovalDocument.find();

        // 获取集合name
        mongoTemplate.getCollectionName(FormDataApproval.class);
    }