多对多关系稍微复杂一些

Question

I have a single table that has 2 many-to-many relationships to another table. Eg:

main
====
id
leftOptions
rightOptions

options
=======
id
option

I need to connect both leftOptions and rightOptions to the options table, so I can't make the usual junction table, with mainId and optionsId as keys.

Also, I'm using mysql, so I'd need something that works with that software.

TIA

Answer 1

I see two ways:

main        mainToOptions        options
====        ============         =======
id          mainId               id
            optionId             option
            isLeft

Or

main        mainToLeftOptions       mainToRightOptions       options
====        =================       ==================       =======
id          mainId                  mainId                   id
            optionId                optionId                 option

However, it's really hard to say which one you should choose without a bigger picture,