my-koa-moban/bin/mongodb.js

var MongoClient = require('mongodb').MongoClient;
var dburl;
var db;
function init() {
    new Promise((res, err) => {
        MongoClient.connect(dburl.url, { useUnifiedTopology: true, useNewUrlParser: true }, (e, db) => {
            if (e) {
                err(e)
            }
            res(db)

        })
    }).then((res) => {
        db = res.db(dburl.dbname)
    }).catch((e) => {
        throw e;
    })
}
let idadd = async (set) => {
    let id = 0
    if (set == "idadd") {
        return 0;
    } else {
        await find('idadd', { 'set': set }).then((res) => {
            if (res.data.length != 0) {
                id = res.data[0].num_key
            } else {
                id = 1
            }
        })
    }

    if (id == 1) {
        await add('idadd', { set, 'num_key': 2 })
    } else if (set != "idadd") {
        console.log(id)

        await update('idadd', { 'set': set }, { 'num_key': id + 1 })
    }
    console.log(id)
    return id

}
let add = async (set, data, url = dburl) => {
    if (set != "idadd") {
        let id = await idadd(set)
        data.num_key = id
    }

    return new Promise((resolve, reject) => {

        try {
            db.collection(set).insertOne(data, function (err, res) {
                if (err) throw err;

                resolve({ code: 0, msg: "添加成功" });
            });
        } catch (error) {
            reject({ code: 1, error })
        }

    });
}
let adds = async (set, data, url = dburl) => {

    if (set != "idadd") {
        for (let i in data) {
            let id = await idadd(set)
            data[i].num_key = id
        }
    }
    return new Promise((resolve, reject) => {

        try {
            db.collection(set).insertMany(data, function (err, res) {
                if (err) throw err;

                resolve({ code: 0, num: res.insertedCount });
            });
        } catch (error) {
            reject({ code: 1, error })
        }

    })
}
let remove = async (set, where, url = dburl) => {
    return new Promise((resolve, reject) => {
        try {
            db.collection(set).deleteOne(where, function (err, obj) {
                if (err) throw err;

                resolve({ code: 0 });
            });
        } catch (error) {
            reject({ code: 1, error })
        }

    })
}
let removes = async (set, where, url = dburl) => {
    return new Promise((resolve, reject) => {
        if (where == "" || Object.keys(where).length == 0) {
            reject({ code: 1 })
        }
        try {
            db.collection(set).deleteMany(where, function (err, obj) {
                if (err) throw err;

                resolve({ code: 0, num: obj.result.n });
            });
        } catch (error) {
            reject({ code: 1, error })
        }

    })
}
let find = async (set, where = {}, page = 0, num = 0, url = dburl) => {
    return new Promise((resolve, reject) => {
        if (num == 0) {
            try {
                console.log(db)
                db.collection(set).find(where).toArray(function (err, result) {
                    if (err) throw err;
                    resolve({ code: 0, data: result });

                });
            } catch (error) {
                reject({ code: 1, error })
            }

        } else {
            try {
                db.collection(set).find(where).skip(num * page).limit(num).toArray(function (err, result) {
                    if (err) throw err;
                    resolve({ code: 0, data: result });

                });
            } catch (error) {
                reject({ code: 1, error })
            }

        }

    })
}
let update = async (set, where = {}, data, defin = true, url = dburl) => {
    return new Promise((resolve, reject) => {
        if (defin) {
            data = { $set: data }
        }
        try {
            db.collection(set).updateOne(where, data, function (err, res) {
                if (err) throw err;
                resolve({ code: 0 });

            });
        } catch (error) {
            reject({ code: 1, error })
        }

    })
}
let updates = async (set, where = {}, data, url = dburl) => {
    return new Promise((resolve, reject) => {
        data = { $set: data }
        try {
            db.collection(set).updateMany(where, data, function (err, res) {
                if (err) throw err;

                resolve({ code: 0, num: res.result.nModified });
            });
        } catch (error) {
            reject({ code: 1, error })
        }

    })
}

module.exports = function (url, dbname) {
    dburl = { url, dbname };
    init();
    return {
        add,
        adds,
        remove,
        find,
        update,
        updates,
        removes
    }
}