Kyle Szklenski

Edit: This is incredibly long with code, and the code is misformatted. I will be reformatting it tomorrow.

I'm going to be writing a long series of posts about the SharePoint object model. This is so others can start learning the model and understand how not to make some of the common pitfalls right away.

First off, SharePoint's object model is very, very deep. You can do a lot of stuff with it and it can seem overwhelming. However, the basics of it are very simple and awesome - that's what I love about it. For example, to query a library is incredibly easy, which makes it trivial to write a one-off app to extract data or statistics from your libraries/lists. Some one-off apps are much harder to write than others, but with the appropriate tooling, I don't think much of anything is impossible in SharePoint, so that makes it powerful.

I'm going to start this series of posts with just that - querying the data to get information back. I'll list the basic objects involved and how to combine them into a coherent program to gather information.

Basic objects:

1. SPListItem - one of the most basic objects in the SP object model; represents any piece of data stored in a list (and by association a library); can be used to get information from, or store information to, any list/library.
2. SPList - the object which represents a list; is a parent of SPDocumentLibrary; most of the time, work with SPList objects when needing to query data.
3. SPQuery - query object; uses CAML to shoot a query off to a list; combined with spList.GetItems(queryGoesHere) to get a collection of items meeting the CAML conditions present in the query; I will not be explaining CAML, but you can learn about it all over the place online, and it's quite trivial to pick up.
4. SPListItemCollection - the collection of objects returned from a query; can be iterated over, i.e. can write foreach to do something to each SPListItem contained therein.
5. SPWeb - the website which contains a list you want to query; in most cases, must be disposed; see best practices for disposing objects; is required for most basic SharePoint object model-related work.
6. SPSite - the site-collection in which the SPWeb object can be found; must also be disposed; is required for most basic SharePoint object model-related work.

So let's just jump right in. Obviously, in order to do this, you have to have the appropriate SharePoint version installed on your computer.

First, make a new test project. Be sure to add a reference to Windows SharePoint Services so that you can import and use all of the objects above. Here is some code:

using System;

using Microsoft.SharePoint;

namespace SampleSharePointObjectModels1

{

class Program

    {

static void Main(string[] args)

        {

// Using "using" here makes it so we don't have to worry about disposing

// these objects directly, even if an exception is thrown inbetween.

using (SPSite site = new SPSite("http://someSiteCollectionUrl"))

            {

// The URLs I'm using obviously won't work on your computers.

// They are fake and somewhat cheesy.

using (SPWeb web = site.OpenWeb("siteRelativeUrlToSomeWeb"))

                {

// This isn't always the best way to get a list, but it's by far the easiest.

SPList someList = web.Lists["listName"];

SPQuery query = new SPQuery();

// If this looks somewhat like XML. . .surprise!

                    query.Query =

"<Where>" +

"<Eq>" +

"<FieldRef Name='someFieldName' />" +

"<Value Type='someValueType'>someValueToCheckFor</Value>" +

"</Eq>" +

"</Where>";

// The following is optional, but will make the search ignore the folder structure.

// In order to also get folders, if necessary, use RecursiveAll. In order to search

// at the base level, there's no need for a scope at all.

                    query.ViewAttributes = "Scope='Recursive'";

// If you know how many results SHOULD be returned, or if you want to page through

// the results, use a RowLimit. This will prevent the database from returning a

// potentially dangerously large number of items.

                    query.RowLimit = 20;

// Gets the list of items based on the query

SPListItemCollection someItems = someList.GetItems(query);

// Just to get rid of redundancies

const string someColumnName = "someColumnName";

// A simple iteration over the list - [] is the indexing operator, which can be used to get a property from the item,

// i.e. the value of some column.

foreach(SPListItem item in someItems)

                    {

Console.WriteLine("For the item named " + item.Name + ", " + someColumnName + " is equal to " + item[someColumnName].ToString());

                    }

                }

            }

        }

    }

}

And that's the basics! If you want or need help, feel free to email me at kszklenski@infusion_NO_SPAM.com. Obviously, remove the part about no spam.