MongoDB and CRUD, or should that be ISUD

I started this blog to remind myself of the solutions to development issues I have along the way and as a general hinting mechanism to remind myself what is going on when I have been away from it for a while. If any of this means that someone else reading this saves themself a world of hurt or going down the rabbit-hole of death, then I'm glad that recording it publically rather than privately was helpful (though conversely, it is always important to learn from one's owner experiences).

In my first posting Simple mongodb equivalents, I wanted to remind myself of some of the basic differences around selection between SQL and NoSQL, and to give concrete examples of what this would look like in Java. In this posting I'll go through the next stage, the hinting mechanism for CRUD.

For those that associate crud with filth, flattery, disgust or disappointment, then you may be on the wrong blog. CRUD stands for CREATE, RETRIEVE, UPDATE, DELETE - though the RETRIEVE is usually replaced by get or SELECT at implemention and CREATE is replaced with INSERT. So, perhaps I'll call it ISUD instead.

First, set up the database, a user and set up an index.

The CREATE (or INSERT) of CRUD (or ISUD)
Here we a setting up some basic data in a collection named 'stuff' that lives in the 'isud' database.

...this is how you would do it from the mongo shell...
...and the Java implementation...

The RETRIEVE (or SELECT) of CRUD (or ISUD)
The selection or retrieval of a document from the collection 'stuff' can be rather powerful, as per Simple mongodb equivalents.

...this is how you would do it from the mongo shell...
...and the Java implementation...
Now let's do a similar thing but this time specify the fields we want returned.

...this is how you would do it from the mongo shell...
...and the Java implementation...

The UPDATE of CRUD
Everyone knows his name was Eric, not Derek, so let's fix that with an update.

...this is how you would do it from the mongo shell...
...and the Java implementation...
Please refer to Updating a document using the default ObjectId for the reasoning behind DBObjectFactory


The DELETE of CRUD
Finally, we can delete a document.

...this is how you would do it from the mongo shell...
...and the Java implementation...
It's all relatively straight forward really. Though none of this is rocket science, I for one find this a useful and succinct reminder or as previously stated; a hinting mechanism.