SharePoint 2010 Step by Step SPQuery List joins Using CAML
I am using the example following example lists
- CustomerCity List
- Customer
List Columns
CustomerCity columns are:
Tilte | Single Line text |
Customer columns are:
Title | Single Line text |
City | Lookup type of CustomerCity |
Dummy Data used
For CustomerCity
Title |
City1 |
City2 |
City3 |
For Customer
Title | City |
Customer1 | City1 |
Customer2 | City1 |
Customer3 | City2 |
Customer4 | City2 |
customer5 | City2 |
Customer6 | <NULL> |
Using the Join in SharePoint 2010 List Using SPQuery Class.
We need to set the three most important properties for that.
- Joins
- ProjectedFields
- ViewFields
SharePoint 2010 adds Join To CAML SPQuery.Joins
Types of joins
- Inner
- Left
Requested Lookup columns
Projections allow inclusion of fields joined lists
SPQeury.ProjectedFields
Joins: Each join is represented by a Join element child of the Joins element. Only inner and left outer joins are permitted. Moreover, the field in the primary list must be a Lookup type field that looks up to the field in the foreign list. There can be joins to multiple lists, multiple joins to the same list, and chains of joins. If a given list is the foreign list in more than one join, it must have distinct aliases assigned to it by the ListAliasattributes of the Join elements representing the joins.
Note: Multiple Lines of text, Choice type columns are not supported in ProjectedFields.
private void button1_Click(object sender, EventArgs e)
{
string siteUrl = "http://home";
SPWeb _web = new SPSite(siteUrl).OpenWeb();
var items =_web.Lists["Customer"].GetItems(GetQuery());
foreach (SPListItem item in items)
{
MessageBox.Show(string.Format("{0}----{1}", item["Title"], item["CityTitle"]));
}
}
private SPQuery GetQuery()
{
SPQuery _query = new SPQuery();
_query.Query = "";
_query.Joins = @"<Join Type='INNER' ListAlias='City'>
<!--List Name: CustomerCity-->
<Eq>
<FieldRef Name='City' RefType='ID' />
<FieldRef List='City' Name='ID' />
</Eq>
</Join>";
_query.ProjectedFields = @"<Field Name='CityTitle' Type='Lookup' List='City' ShowField='Title' />
<Field Name='CityContentTypeId' Type='Lookup' List='City' ShowField='ContentTypeId' />";
_query.ViewFields = @" <FieldRef Name='Title' />
<FieldRef Name='CityTitle' />";
return _query;
}
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