MongoDB - Find Queries

This is the simplest of the MongoDB queries. A simple find operation.

connecting to test  
> db.people.find().pretty();
{
  '_id' : ObjectId('5561e...')
  'name' : 'Craig Derington',
  'address' : {
      'street' : '1234 Main Street',
      'city' : 'Coos Bay',
      'state' : 'OR',
      'zip_code' : '97402'
  },
  'profession' : 'Developer',
  'email' : 'craig@craigderington.me',
  'phone_number' : '541-555-1212',
  'is_active' : True,
}
Type "it" for more  

The expression we typed into the shell, broken apart to show each part of the query.

db = the start of the command  
people = the collection in which to search  
find() = the operation to perform, with no operators  
pretty() = make the output readable  

Our queries can get much more complex with larger collections.

Let's imagine we had a collection with millions of records. We would never want to run a find() query, because that would be a waste of resources.

Instead, we need to pass operators to the find clause.

connecting to: test  
> db.people.find({ 'name' : { $regex : 'je' }, 'email' : { $exists : true }})
{
  '_id' : ObjectId('5561e...')
  'name' : 'Jeff Wilson',
  'address' : {
      'street' : '444 S. Broadway',
      'city' : 'Portland',
      'state' : 'OR',
      'zip_code' : '97201'
  },
  'profession' : 'Engineer',
  'email' : 'craig@craigderington.me',
  'phone_number' : '503-444-1312',
  'is_active' : True,
}

Here is a link to a decent cheat sheet for MongoDB queries. Link

SQL to Mongo DB query translator Link

Craig Derington

Full Stack Developer. Linux, Docker, Python, Celery, Flask, Django, Go, MySQL, MongoDB and Git. Modern, secure, high-performance applications capable of processing millions of transactions a day.

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