To find documents in the collection that meet some criteria, use the
query()method. This method accepts either a string which is an
adapter-dependent query and is passed as-is to the concrete adapter, or a structured query
object instance of Zend_Cloud_DocumentService_Query. The return
is a Zend_Cloud_DocumentService_DocumentSet, containing instances
of Zend_Cloud_DocumentService_Document that satisfy the query.
The DocumentSet object is iterable and countable.
Example 81. Querying a collection using a string query
<?php
$docs = $documents->query(
"collectionName",
"RowKey eq 'rowkey2' or RowKey eq 'rowkey2'"
);
foreach ($docs as $doc) {
$id = $doc->getId();
echo "Found document with ID: "
. var_export($id, 1)
. "\n";
}
If using a structured query object, typically, you will retrieve it using the
select() method. This ensures that the query object is specific
to your adapter, which will ensure that it is assembled into a syntax your adapter
understands.
Example 82. Querying a collection with structured query
<?php
$query = $service->select();
$query->from('collectionName')
->where('year > ?', array(1945))
->limit(3);
$docs = $documents->query('collectionName', $query);
foreach ($docs as $doc) {
$id = $doc->getId();
echo "Found document with ID: "
. var_export($id, 1)
. "\n";
}
Zend_Cloud_DocumentService_Query classes do not limit which query
clauses can be used, but the clause must be supported by the underlying concrete
adapter. Currently supported clauses include:
-
select()- defines which fields are returned in the result.Note
Windows Azure ignores this clause's argument and always returns the whole document.
from()- defines the collection name used in the query.where()- defines the conditions of the query. It accepts three parameters: condition, array of arguments to replace "?" fields in the condition, and a conjunction argument which should be "and" or "or", and which will be used to join this condition with previous conditions. Multiplewhere()clasues may be specified.whereId()- defines the condition by document ID (key). The document matching must have the same key. The method accepts one argument - the required ID (key).limit()- limits the returned data to specified number of documents.-
order()- sorts the returned data by specified field. Accepts two arguments - first is the field name and second is 'asc' or 'desc' specifying the sort direction.Note
This clause is not currently supported by Windows Azure.