Adding HAVING clause support to generic query generator

[OtaK]

Hi guys, hi @sdepold,

As I needed it, I added HAVING clause support to Sequelize's generic query generator.

Do I need to provide unit tests or is it okay like that ?

HOW TO USE

As the specification says, HAVING clauses are syntactically the same as WHERE clauses.
So in your Model.findAll() for example, provide a having option in the hash.

Like this :

Model.findAll({
    ...
    having: { myField: { gt: 600 } },
    ...
}).success(...).error(...);

[mickhansen]

Please do provide unit tests when introducing new functionality, else we will have no clue if we break it later on.

[OtaK]

Just pushed some commits with bugfixes, improvements, code style, and unit tests :)

[mickhansen]

Great stuff, i see you added tests to mysql query generator, mind adding to sqlite and postgres aswell? :)

[OtaK]

Here it is for you :-)

[mickhansen]

Ah, we merged some work in the meanwhile, mind rebasing? I cant merge automatically.

[OtaK]

Just pushed the merge. Let's wait for Travis to complete the build.

[mickhansen]

Sweet :)

[mickhansen]

Mind adding a small doc to the original description of this PR describing how to use it?

[OtaK]

@mickhansen Done. Does it look okay for you?

[mickhansen]

@OtaK Perfect! Thank you for your work.