Using Caché Objects - InterSystems Documentation

Streams
Set stream=##class(%Stream.Object).%Open(memo)
Since the %Open method is fully polymorphic, the actual type of stream returned by
%Open depends on what type is stored with the Person object
• Read and process the stream data, closing the stream when done:
Write stream.Read(100)
Do stream.%Close()
Writing a stream is similar. There are several ways to do this. In the first, we get an oref value
and use it to insert the stream into the table:
//Create a stream and write data to it
Set stream = ##class(%GlobalCharacterStream).%New()
Do stream.Write("Do re mi fa sol...")
//Save the stream, record the stream oref in the %qstrhandle
//structure, and turn the stream into a string representation
//of an oref:
Do stream.SaveStream()
Set %qstrhandle(1,stream) = stream
Set stream = stream_""
//INSERT this string-oref value into the table, closing the
//stream when done:
&sql(INSERT INTO Person (Name,Memo) VALUES (:name, :stream))
Kill %qstrhandle(1,stream)
The second approach is similar, but uses %qacn instead of 1 in the %qstrhandle array. There
is no need to save the stream before passing the oref. The filer will actually look for
%qstrhandle($g(%qacn,1),stream)
//Create a stream and write data to it
Set stream = ##class(%GlobalCharacterStream).%New()
Do stream.Write("Do re mi fa sol...")
//Record the stream oref in the %qstrhandle structure, and
//turn the stream into a string representation of an oref.
Set %qacn=100
Set %qstrhandle(%qacn,stream) = stream
Set stream = stream_""
//INSERT this string-oref value into the table, closing
//the stream when we are done:
&sql(INSERT INTO Person (Name,Memo) VALUES (:name, :stream))
Kill %qstrhandle(%qacn,stream)
You can also insert a literal value directly into the table:
//Define the literal value and write it into the table
Set stream = "Do re mi fa sol..."
&sql(INSERT INTO Person (Name,Memo) VALUES (:name, :stream))
Kill %qstrhandle(1,stream)
138 Using Caché Objects