Is there a floor function in Mongodb aggregation f

问题:

I try to do some integer math in mongodb and have some problems. Is there a way to round doubles up or down in the mongo db aggregation framework?

回答1:

As per the comment from Stennie, the floor and ceiling methods are not supported.

And as per my comment above, the best solution that I could find was just doing an operation that looks like: (num-mod(num,1)) which should yield the same result as the floor function.

回答2:

Starting from MongoDB 3.2, you can use the following arithmetic aggregation operators are available:

• ceil
• trunc
• floor

which allow to convert to integer from any side you want. The syntax is straight-forward: { $function: <number> }