主题目录

• Storing Large Amounts of Data with Streams in ObjectScript

  Storing Large Amounts of Data with Streams in ObjectScript

  Content Type
  Video

  Duration
  5m

  Level
  Introductory

  Learn how InterSystems IRIS® data platform handles large character and binary data using its stream classes in InterSystems ObjectScript. See when to use global, temporary, and file streams and how to create and read stream data. Learn how to use iFind to make stream content searchable and to manage streams operations such as writing and clearing content.
• Code Used in This Video

  Code Used in This Video

  Reference	Timestamp	Code
  Creates a new Hospital.Patients object instance and assigns the patient’s Name property to John Smith.	2:30	Begin code: set patient = ##class(Hospital.Patient).%New() set patient.Name = "John Smith” End code,
  Writes following the previous written line to the patient’s Notes stream.	2:45	do patient.Notes.Write(" ")
  Writes a line to the patient’s Notes stream.	2:45	do patient.Notes.WriteLine(" ")
  Persists the patient object to the database by saving it.	2:55	do patient.%Save()
  Retrieves the Hospital.Patients record with ID 1 from the database and assigns it to the patient object.	3:00	set patient = ##class(Hospital.Patients).%OpenId(1)
  Moves the write/read position of the patient’s Notes stream to the end so new content can be written without overwriting it.	3:05	do patient.Notes.MoveToEnd()
  Resets the patient’s Notes stream position to the beginning so it can be read from the start.	3:20	do patient.Notes.Rewind()
  Reads and prints the next line from the Notes stream, then outputs a new line.	3:25	write patient.Notes.ReadLine(),!
  Reads and prints 25 characters of the Notes stream from the current position.	3:30	write patient.Notes.Read(25)
  Defines a basic iFind index on the Notes field to enable full-text search.	3:40	Index NotesIndex On (Notes) As %iFind.Index.Basic;
  Performs an SQL query that uses an iFind text index to search the Notes field for the term headache and returns the matching patients.	3:55	Begin code: SELECT ID, Name, Notes FROM Hospital.Patients WHERE %ID %FIND search_index(NotesIndex, 'Headache'); End code,
  Clears all content from the patient’s Notes stream, leaving it empty.	4:10	do patient.Notes.Clear()
• What's Next?

  What's Next?
  • Read more about how to work with streams (documentation, 20m).