mongodb sql-comparison

http://docs.mongodb.org/manual/reference/sql-comparison/

SQL Terms/Concepts MongoDB Terms/Concepts database database table collection row document  or   BSON  document column field index index table joins embedded documents and linking  

primary key

Specify any unique column or column combination as primary key.

primary key

In MongoDB, the primary key is automatically set to the_id field.

aggregation (e.g. group by)

aggregation pipeline

See the SQL to Aggregation Mapping Chart.