Learn how to store and retrieve files from the database using Mongo’s GridFS and ProdigyView.

1. MongoDB and GridFS

2. Overview
Objective
Learn how to store and retrieve files from the database using
Mongo’s GridFS and ProdigyView.
Requirements
 Installed PECL Mongo Extension
 A Mongo Database
 Understanding of MongoDB Basics with ProdigyView
 Understanding of connecting to a database in ProdigyView
Estimated Time
10 Minutes

3. Follow Along With Code
Example
1. Download a copy of the example code at
www.prodigyview.com/source.
2. Install the system in an environment you feel comfortable
testing in.
3. Proceed to examples/database/MongoGridFS.php
www.prodigyview.com

4. What Is GridFS
The GridFS is MongoDB’s way of storing files in the
database. The files are stored in binary chunks that are
around 256k in size.
File
GridFS
Chunk Chunk Chunk Chunk Chunk Chunk

5. File Information
Before the file is entered into Mongo, we need to setup options and
variables. The data inserted with the file will become the meta data.
The data is used to describe the file stored.
1. Insert data will act as the file meta data
2.Set the option to GridFS to 3. Set the file to the location of on the
true server

6. Insert File
Then pass the insert data(meta data) and the options to
PVDatabase::insertStatement() and the process of
putting the file in the database will be handled for you.
1. The collection name 2. The meta data about the file
4. Returns a Mongo ID 3. The options for uploading

7. Searching GridFS
Searching in GridFS uses the same syntax as a regular
search in ProdigyView except the gridFS option has to be
set to true.
1. Search based on these arguments 2. Set the collection name
3. Set gridFS to true

8. Getting a Single File
Also similar is retrieving a single file. The only difference again is
to the gridFS option and combine it with the findOne option.
1. Set gridFS to true
2. Set findOne to True

9. Displaying The Image
In our example, we uploaded images to the database. Now
we need to retrieve the image and display it. Using
getBytes() method, we can read in the chunks from the
document retrieved from gridFS. This will return a string of
bytes.
1. Get the image bytes from the result 2. Write the bytes to file
3. Display the image
www.prodigyview.com

10. Updating GridFS
When updating a file in gridFS, we can modify the meta
data of the file. The update mechanics work the same way
when updating a normal document except the gridFS must
be set to true. The file itself will be unaltered.
1. Collection name 2. The fields to update 3. Where to update
4. Set gridFS to true

11. Deleting File
The final action is deleting a file. On delete, the meta data and
chunks be removed from the database. The same syntax from
the select statement is used.
www.prodigyview.com

12. API Reference
For a better understanding of the database, visit the api
by clicking on the link below.
PVDatabase
More Tutorials
For more tutorials, please visit:
http://www.prodigyview.com/tutorials
www.prodigyview.com