The Tamino XQuery language can be used both to query Tamino XML documents and also to update them. For more information about the Tamino XQuery language, please refer to the Tamino Server documentation.
The Tamino API for .NET provides the
Query method of the
TaminoCommand to execute both kinds of transaction. The
Query method always returns a
TaminoQueryResponse object. Iterators can be requested
from this TaminoQueryResponse object to process the
returned query result set.
When querying data from the database, the returned query result is built
according to the specified query. In the case of a query that updates XML data
in Tamino, the returned query result set consists of a list of information that
identifies the affected XML documents in Tamino. The application can use the
serialization class TaminoUpdateItem to access this
identifying information easily.
...
// querying data from Tamino
TaminoQuery query = new TaminoQuery ("input()/Property");
TaminoQueryResponse queryResponse = command.Query(query);
...
...
// updating data in Tamino
TaminoQuery updateQuery =
new TaminoQuery("update replace for $p in input()/Property//Name where
$p=’Hugo Maier’ with <Name>Hugo Meier</Name>");
TaminoQueryResponse updateResponse = command.Query(updateQuery);
TaminoUpdateItem updateItem =
(TaminoUpdateItem) updateResponse.GetSingleItem(typeof(TaminoUpdateItem));
Console.WriteLine("collection="+updateItem.collection+" doctype"+
updateItem.doctype+" id="+updateItem.id);
...If a query is expected to return a very large result set, it is
generally better not to return the complete query result set all at once.
Instead, the application can specify that the result set should be retrieved
page by page. This is done by specifying a page size in the
Query method of the
TaminoCommand. If a page size greater than 0 is
specified, the Tamino API for .NET will use the
Tamino cursor.
A cursor can only be used for querying data from Tamino. It cannot be used in conjunction with an XQuery update expression.
A cursor can only be used within the scope of a local or global transaction (see dotnetapiref/SoftwareAG.Tamino.Api.TaminoConnectionMode.html).
TaminoConnection connection = new TaminoConnection("http://myserver/tamino/mydb");
connection.Open(TaminoConnectionMode.LocalTransaction);
TaminoTransaction transaction = connection.BeginTransaction();
TaminoCommand command = connection.CreateCommand("mycollection");
// 10 items per page
TaminoQueryResponse qr = command.Query(new TaminoQuery("input()/Property"),10);
...
You should call the Close method in the
TaminoQueryResponse object when the query result set is
no longer required, in order to release resources such as Tamino cursors.
Resources are not implicitly released when the
TaminoQueryResponse object falls out of scope or is
reclaimed by the garbage collector.
