Are SharePoint Lists evil in an SOA based enterprise?_问答_开发者

My company is moving from Client/Server applications (thick client apps that makes database calls directly) to a Service Oriented Architecture (SOA) (thin or thick clients that call a web service that then does business logic and calls the database).

Part of this includes using SharePoint as our client (not our only client type, but the major one). I have been watching the Pluralsight training on SharePoint and I开发者_运维知识库 am starting to see a lot about SharePoint Lists.

SharePoint Lists seem to be to a core part of SharePoint. However they also seem to be a huge step backward architecturally speaking. These are my concerns:

Using these lists, I will have my SharePoint webparts hitting the data directly again (much like where we were with 2 tier client/server apps).
This confuses the data layer big time. Do I store my list of clients in the SQL Server database? Or a SharePoint list? Or both? (say it ain't so!) If both, how do I keep them in Sync?
If I store the data in SharePoint Lists do I then have to have my Web Services using the SharePoint Client Object Model to get at the lists (for non-SharePoint clients)?

Basically SharePoint Lists seem like a very very bad idea. But what I hear is that it is one of the big benefits of SharePoint. (Though I know that there are things like resource management and permissions that are also useful in SharePoint.)

SharePoint Lists seem like an attempt at low grade data storage. (With out all the benefits of a full data management solution like SQL Server.)

So here are my questions: What are the right/best practice reasons why would I use SharePoint Lists over web services that access a SQL Server? And can SharePoint even work normally using web services to get and update data? (Basically, if I don't use lists, do I lose a lot of functionality?)

SharePoint lists are not a one size fits all solution to data storage. There are a great deal of scenarios where you'll want to use data available from an external system, like an existing CRM database, inside of SharePoint.

SharePoint 2007 used a concept called Business Data Catalog to address some of these scenarios, allowing a read-only view of external system data in SharePoint lists.

SharePoint 2010 greatly expands on the SharePoint 2007 capabilities with Business Connectivity Services, allowing for full read/write from SharePoint lists, with API access allowing custom connectors to be implemented in code for whatever backend system you may be trying to access (a SQL Server provider is provided out of the box). Here's a pretty thorough primer on the BCS, and there's a lot more information to be found on MSDN.

Be wary of trying to use SharePoint lists as traditional tables in a RDBMS, these aren't their purpose and it will only lead to intense headaches down the road.

While I agree with the answer by OedipusPrime, I feel your question "Why would I use lists" warrants a more detailed answer.

The short version is, you probably shouldn't. What SharePoint gives you are lists which are a bit 'database-like', but simple enough that your ordinary user can cope with them. They're quite flexible for users. It also gives you a user interface to interact with the lists and data.

You're not using the UI, and you're probably quite happy with SQL, so SQL should probably be your choice. There's nothing that you can do in SharePoint that you can't do yourself in SQL (often faster) - but SQL isn't as user friendly for non-techies to set things up. SharePoint isn't a "full data management solution" like SQL - it's more like ASP.NET on steroids, and it has different advantages. (That's why its back end is ... SQL)

So, where would you store your data? SQL or Lists. One or the other - don't do both, that never works out well. If your data is in SQL, you can expose it in SharePoint with the BCS as mentioned already.

If your data is in a SharePoint list, yes, you can use the Client Object model. Or you can use Web Services directly. Or the REST API. All those are valid options.

Or, you could expose data from your database via your own Web Services, and then consume those via SharePoint's BCS, allowing you to present your data in SharePoint (with full CRUD, if you want) without your application becoming dependent upon it.

You are partially right. Regarding your options, here is the route you should go:

You should store the data only in lists. Not in SQL server. The data in lists is ultimately stored in SharePoint content database in SQL server and there is no point syncing it.

To have your clients access the data, your web services can call out of the box web services exposed in SharePoint which can operate on lists data.

See this article on overview of web services exposed by SharePoint: http://msdn.microsoft.com/en-us/library/ee538665.aspx http://www.sharepointmonitor.com/2007/01/sharepoint-web-service/

This is one of the big questions that faces someone new to SharePoint - should I store X in a SharePoint list, or in a SQL Server table?

SharePoint lists have similarities to database tables in that they have rows (items) and columns and the equivalent of triggers (event receivers). Data management pages are part of SharePoint so there is no need to build pages for updating and adding items to the table, and additionally the lists can be exposed as RSS feeds or through web services. They can also be versioned and participate in a workflow. Another advantage is that the contents of the lists are automatically included in content backups, so there is no need to manage a separate backup and restore process – everything is in the content database. There may not necessarily be a performance impact because there are several caching mechanisms which come into play.

A SharePoint list should certainly be considered as a storage mechanism, even for large datasets with appropriate treatment. In one sense the SharePoint list is acting as an effective data access layer, bearing in mind that ultimately the data is being stored in a SQL Server database anyway. What you do not get is the rigour of relational modelling, normalisation, referential integrity, optimisation of the execution plan, and all the other tools of the DBA’s craft. If the efficient management of the data is dependent on those skills then storing the data directly in its own database is probably a better choice. You can still get at the data through BCS, as well as through custom code.

A word of warning: on no account be tempted to interact with the SharePoint content databases directly.