Working with CAML Queries and SPQuery

CAML Queries

In sharepoint if we want to retrieve the data from Lists we need to use CAML Queries

CAML stands for Collaberative application markup language,which is basically xml format language query style.

To query the list we need to use SPQuery object by creating new object and assigned the CAML query to SPQuery.Query

CAML Query operators

Operator                Description

And                 It will be used to combined the two or more conditions or multiple conditions

BeginsWith      Searches for a string at the beginning of the text field

Contains         Searches for a string within the text field

Eq                Equal to

FieldRef         A reference to a field (useful for GroupBy elements)

Geq              Greater than or equal to

GroupBy       Groups results by these fields

Gt                 Greater than

IsNotNull      Is not null (not empty)

IsNull            Is null (empty)

Join               Used to query across two lists that are joined through a Lookup field

Leq               Less than or equal to

Lt                  Less than

Neq             Not equal to

Now            The current date and time

Or               Boolean or operator

OrderBy     Orders the results of the query

Today         Today’s date

TodayIso    Today’s date in International Organization for Standardization (ISO) format

Where       Used to specify the Where clause of the query 

the following example will list out all the announcements which are not expired till date,we will be fetching all announcements "Title"

Code Sample:

SPQuery query = new SPQuery;

query.Viewfields = @"<fieldref name="Title"><fieldref name="Expires">";

query.Query =

@"<where>

<lt>

<fieldref name="Expires">

<value type="DateTime"><today></today></value>

</fieldref></lt>

</where>";

SPList list = SPContext.Current.Web.Lists.TryGetList("Announcements");

SPListItemCollections items = list.GetItems(query);

Here "items" are announcements title result</fieldref></fieldref>