db.collection() is not a function

当我尝试使用node连接mongodb时，运行data文件，结果出现以下报错：

TypeError: db.collection is not a function
    at insertData (D:\workcode\my-app\server\data\insert_db.js:8:25)
    at D:\workcode\my-app\server\data\insert_db.js:22:5
    at result (D:\workcode\my-app\server\node_modules\mongodb\lib\utils.js:414:17)
    at executeCallback (D:\workcode\my-app\server\node_modules\mongodb\lib\utils.js:406:9)
    at D:\workcode\my-app\server\node_modules\mongodb\lib\mongo_client.js:325:5
    at connectCallback (D:\workcode\my-app\server\node_modules\mongodb\lib\mongo_client.js:1047:5)
    at D:\workcode\my-app\server\node_modules\mongodb\lib\mongo_client.js:900:11

    at process._tickCallback (internal/process/next_tick.js:176:11)

解决方法：将mongodb版本更新为^2.2.33，即运行npm install mongodb@^2.2.33 即可