mongodb备份报错 too many positional options

Question

目的是想备份整个项目的全部数据，不限于某一个collection

使用的命令：
mongoexport —db Demo —out demo_backup.json

运行后报错：
Error parsing command line: too many positional options

求各位大神帮忙

Answer 1

I solved this problem by removing the spaces between the fields to be exported after the -f parameter. Then it's fine.

Answer 2

Found the answer on stack overflow
mongodump -d Demo -o demo_backup.json

http://stackoverflow.com/questions/7521163/what-does-too-many-positional-options-mean-when-doing-a-mongoexport

I don’t know how to solve the problem if I continue to use mongoexport