DataTable vs. Collection in .Net

Question

I am writing a program that needs to read a set of records that describe the register map of a device I need to communicate with. Each record will have a handfull of fields that describe the properties of each register.

I don't really need to edit or modify the data in my VB or C# program, though I would like to be able to display the data on a grid. I would like to store the data in a CSV file, or perhaps an XML file. I need to enable users to edit the data off-line, preferably in excel.

I am considering using a DataTable or a Collection of "Register" objects (which I would define).

I prototyped a DataTable, and found I can read/write XML easily using the built in methods and I can easily bind to a DataGridView. I was not able to find a way to retreive info on a single register without using a query that returns a collection of rows, even though I defined a unique primaty key column. The syntax to get a value from a column is also complex, though I could be missing something on both counts.

I'm tempted to use a collection of "Register" objects that I can access via a unique key. It would be a little more coding up front, but seems like a cleaner solution overall. I should still be able to use LINQ to dataset to query subsets of registers when I need them, but would also be able to grab a single field using a the key value, something like this: Registers(keyValue).fieldName).

Which would be a cleaner approach to the problem?

Is there a way to read/write XML into a Collection without needing custom code?

Could this be accomplished using String for a key?

UPDATE: Sounds like the consensus is towards the Collection of register Objects. Makes sense to me. I was leaning that way, and since nobody pointed out any DataTable features that would simplify acessing a single row, it looks like the Collection is clearly the way to go. Thanks to those who weighed in.

Answer 1

I would be inclined not to use data sets. It would be better to work with objects and collections. Your code will be more maintainable/readable, composable, testable & reusable.

Given that you can do queries on the data set to return particular row, you might find that a LINQ query to turn the rows into objects may be all the custom code that you need.

Using a Dictionary<string, Register> for look ups is a good idea if you have a large number of items (say greater than 1000). Otherwise a simple LINQ query should be fine.

Answer 2

It depends on how you define 'clean'.

A generic collection is potentially MUCH more lightweight than a DataTable. But on the other hand that doesn't seem to be too much of an issue for you. And unless you go into heavy reflection you'll have to write some code to read/write xml.

If you use a key I'd also recommend (in the case of the collection) to use a Dictionary. That way you have a Collection of the raw data and still can identify each entry through the key in the Dictionary.

Answer 3

I would go with the collection of objects so you can swap out the data access later if you need to.

Answer 4

Hey,

You can serialize classes with an xml serializer and defining a Serialize attribute or something like that (it has been a while since I done that, sorry for the vagueness). A DataSet or DataTable works great with XML.

Both DS and DT have ReadXml and WriteXml methods. XML must be predefined format, but it works seamlessly.

Otherwise, I personally like collections or dictionaries; DS/DT are OK, but I like custom objects, and LINQ adds in some power.

HTH.

Answer 5

I usually use datatables if its something quick and unlikely to be used in any other way. If it's something I can see evolving into an object that has its own use within the app (like your Register Object you mentioned).

It might be a little extra code up front - but it saves converting from a datatable to the collection in the future if you come up with something you would like to do based on an individual row, or if you want/need to add some sort of extra functionality to that element down the road.