How to insert an Array/Objet into SQL (bestpractice)

Question

I need to store three items as an array in a single column and be able to quickly/easily modify that data in later functions.

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To be clear, I love and use x_ref tables all the time but an x_ref doesn't work here because this is not a one-to-many relationship. I am making a project management tool that among other things, assigns a user to a project and assigns hours to that project on a weekly basis, per user, sometimes for weeks many weeks into the future. Of course there are many projects, a project can have many team members, a team member can be involved with many projects at one time BUT its not one-to-many because a team member can be working many weeks on the same project but have different hours for different weeks. In other words, each object really is unique. Also/finally, this data can be changed at any time by any team-member - hence it needs to be easily to manipulate.

Basically, I need to handle three values (the team member, the week we're talking about, and how many hours) dropped into a project row in the projects table (under the column for project team members) and treated as one item - a team member - that will actually be part of a larger array of all the team members involved on the project.

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So assuming that the application's general schema and relation tables aren't total crap and that we are in fact up against a wall in this one case to use an array/object as a value for this column, is there a best practice for that? Like a particular SQL data-type? A particular object/array format? CSV? JSON? XML? Most of the app is in C# but (for very odd reasons that I won't explain) we could really use any environment if there is a particular one that handles this well.

For the moment, I am thinking either (webservice + JS/JSON) or PHP unserialize/serialize (but I am bit sketched out by the PHP solution because it seems a bit cumbersome when using ajax?) Thoughts anyone?

Answer 1

Hmm it sounds like you should rethink your schema, If I understand you why don't you just create one like this:

Users
  ...
Projects
  ...

WorkItemTracking 
  UserId
  ProjectId
  Week // between 1 and 52, or a datestamp
  Hours // number of hours budgeted for this task this week

To find what the user is doing for the next 3 weeks,

SELECT * form workItemTracking where userId = <id> and week between <weekstart> and <weekend>

This will give you the ability to assign multiple users to multiple projects, and projects to multiple users. It also makes updating easy. Does this make sense?

Answer 2

Could you flatten the array into a text column and use some special token to separate each piece of data, for example the string Joe/03/25 would be an array someArray={'Joe','03','25'}. Would that work?

I admit there could be problems with this approach. For example, if you want to search this column for "Joe" you'd have to use ...LIKE 'Joe%'. Doesn't seem very indexable, so your queries will be a little slow.

Some databases such as Oracle actually allow array types as column types (I think these are also sometimes called Nested Tables), and I think (could be wrong though) that you can search and index the elements of an array in a column. You didn't specify which database vendor you were working with, so it's possible that you might be able to get this as a proper array, depending on which technology you choose.

Answer 3

For the sake of anyone else wondering...

"Damnit Byron you got me; I hate looking stupid on the interweb haha. But you're right - that really is the better solution. THANKS!"