text 蒙戈集团

Posted 2021-05-03

db.<collection_name>.aggregate([{$group: {_id:{'groupByThis':'$<group_by_this_field>'},'count':{$sum:1}}}]);
#example:
db.survey_data.aggregate([{$group: {_id:{'execution_id':'$execution_id'},'count':{$sum:1}}}]);