重新组织 mongoDB数据库中的 数据格式

1 数据库导出

mongoexport -d dbName -c collectionName -o ./data.js

得到data.js，现格式如下

{"_id":"24Fgub3Z","createdAt":{"$date":"2011-10-14T08:29:18.395Z"},"services":{"password":{"bcrypt":"$2a$10$3s8QZCDR7lcl10e.02HWU.PiLqYzBK0pfdGEwFQC07gi/4EwYNRyG"},"resume":{"loginTokens":[]}},"username":"Trump","emails":[{"address":"xx@xx.com","verified":false}],"paidCourses":["2343243", "2323432"],"team":[]}
{"_id":"3rEtC9W2","createdAt":{"$date":"2011-05-16T11:38:31.644Z"},"services":{"password":{"bcrypt":"$2a$10$LDcd6kxMm0BqZbD0pIhjZe4GcDPoMe0MQ3Bs3hkw3evT00297B2VS"},"resume":{"loginTokens":[]}},"username":"Obama","emails":[{"address":"bbc@163.com","verified":false}],"paidCourses":["h2333666"],"team":[8.0]}

2 JS处理数据的思路（index.js）

• 读取数据文件为字符串

  • fs

• 按换行符切分字符串，得到数组，数组元素为各条document

  • split(）

• 逐条将数组中的字符串转换为对象，并按需重新组织结构

  • map() / filter() / forEach()
  • JSON.parse转换
  • 利用临时数组intermediaArr保存结果

• 但此时还不能直接输出，否则会得到[object Object],[object Object]。所以再逐条将其转换为JSON string

  • map()
  • JSON.stringify()

• 将map得到的数组处理为可以导入数据库的字符串

  • join('\n')

• 输出文件

  • fs

输出为temp.js ，已经得到想要的格式

{"_id":"24Fgub3Z","username":"Trump","password":"$2a$10$3s8QZCDR7lcl10e.02HWU.PiLqYzBK0pfdGEwFQC07gi/4EwYNRyG","paidCourses":["2343243","2323432"],"createdAt":"2011-10-14T08:29:18.395Z"}
{"_id":"3rEtC9W2","username":"Obama","password":"$2a$10$LDcd6kxMm0BqZbD0pIhjZe4GcDPoMe0MQ3Bs3hkw3evT00297B2VS","paidCourses":["h2333666"],"createdAt":"2011-05-16T11:38:31.644Z"}

3 将新数据导入数据库

mongoimport -d dbName -c collectionName --file temp.js

更新

• 使用了ES6新特性
  • 解构
  • for-of
  • 对象字面量属性值简写

参考文档

• JSON.stringify()

• JSON.parse()