Review and propose changes of database package v1.1

[johnding1996]

Database package v1.1 is released recently, but, as excepted, there might be bugs and things to review and revise in it. This issue serves as the dialog to propose changes of v1.1. @WSGuo and I will update it to v1.2 very soon.

[johnding1996]

Issue 1: querier.get method may cause exceptions when not found, and this is not even covered by unittests.

[johnding1996]

Issue 2: change user_id to hash code of length 32 char(32).

[johnding1996]

Issue 3: the set of states are changed, update this in StateKeeper class

[johnding1996]

Issue 4: maybe reference the set of valid states inside the controller, to avoid duplicated definition of states in the whole project.

[johnding1996]

Issue 5: Querer.add expect knowing the ids before adding it to the DB, but actually we do not know which id is occupied. Please use 100~200 currently

[johnding1996]

Issue 6: some overload methods of add, update, delete could be implemented easily and good to use.

[johnding1996]

Issue 7: some constructors are not public, should made default and useful constructor public

[johnding1996]

All potential issue collected, will update database package and merge to develop tomorrow morning. The new version number will be v1.2

[thomaszhouan]

The visibility of constructors of querier classes is default, how to instantiate a querier in another package say agent?

[johnding1996]

@thomaszhouan thanks for pointing out this, it already list in issue 7.

[johnding1996]

@thomaszhouan As for Issue 4, I just found that stateNameSet is already defined in State class. Should I make it public to use it in the StateKeeper? A better method is to make a public get method.

[thomaszhouan]

For validation, you could call the public method validateStateName

[johnding1996]

@thomaszhouan Great, sorry for not finding it before.

[johnding1996]

Closed since database v1.2 is released