SQL to MongoDB Mapping Chart

The following table presents the various SQL terminology and concepts and the corresponding MongoDB terminology and concepts.

<col>

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​​.

The following table presents some database executables and the corresponding MongoDB executables. This table is not meant to be exhaustive.

MongoDB

MySQL

Oracle

Informix

DB2

Database Server

​​mongod​​

mysqld

oracle

IDS

DB2 Server

Database Client

​​mongo​​

mysql

sqlplus

DB-Access

DB2 Client

The following table presents the various SQL statements and the corresponding MongoDB statements. The examples in the table assume the following conditions:

The SQL examples assume a table named users.

The MongoDB examples assume a collection named users that contain documents of the following prototype:

{

_id: ObjectId("509a8fb2f3f4948bd2f983a0"),

user_id: "abc123",

age: 55,

status: 'A'

}

The following table presents the various SQL statements related to table-level actions and the corresponding MongoDB statements.

SQL Schema Statements

MongoDB Schema Statements

Implicitly created on first ​​insert()​​ operation. The primary key _id is automatically added if _id field is not specified.

However, you can also explicitly create a collection:

Collections do not describe or enforce the structure of its documents; i.e. there is no structural alteration at the collection level.

However, at the document level, ​​update()​​ operations can add fields to existing documents using the ​​$set​​ operator.

However, at the document level, ​​update()​​ operations can remove fields from documents using the ​​$unset​​ operator.

The following table presents the various SQL statements related to inserting records into tables and the corresponding MongoDB statements.

SQL INSERT Statements

MongoDB insert() Statements

The following table presents the various SQL statements related to reading records from tables and the corresponding MongoDB statements.

SQL SELECT Statements

MongoDB find() Statements

or

The following table presents the various SQL statements related to updating existing records in tables and the corresponding MongoDB statements.

SQL Update Statements

MongoDB update() Statements

The following table presents the various SQL statements related to deleting records from tables and the corresponding MongoDB statements.

SQL Delete Statements

MongoDB remove() Statements