请在云函数中使用

// 云函数入口文件

const cloud = require(‘wx-server-sdk’)

cloud.init()

const db = cloud.database({

    env: ‘环境ID’

})

const _ = db.command

const $ = db.command.aggregate

// 云函数入口函数

exports.main = async(event, context) => {

    let table = ‘集合名称’

    return db.collection(table).aggregate()

        .addFields({

            match: $.eq([’$type’, ‘type1’])

        })

        .match({

            match: !0

        })

        .sample({

            size: 1 // 随机取一条type=type1的记录

        })

        .group({

            _id: ‘any’,

            type1Row: $.push(’$$ROOT’)

        })

        .lookup({

            from: table,

            pipeline: $.pipeline()

                .addFields({

                    match: $.eq([’$type’, ‘type2’])

                })

                .match({

                    match: !0

                })

                .sample({

                    size: 1 // 随机取一条type=type2的记录

                })

                .done(),

            as: ‘type2Row’,

        })

        .addFields({

            allRows: $.concatArrays([’$type1Row’, ‘$type2Row’])

        })

        .unwind(’$allRows’)

        .replaceRoot({

            newRoot: ‘$allRows’

        })

        .end()

}