Document Structure Use Cases

In addition to defining data records, MongoDB uses the document structure throughout, including but not limited to: query filters, update specifications documents, and index specification documents

Query Filter Documents

Query filter documents specify the conditions that determine which records to select for read, update, and delete operations.

You can use <field>:<value> expressions to specify the equality condition and query operator expressions.

{
  <field1>: <value1>,
  <field2>: { <operator>: <value> },
  ...
}

For examples, see:

Update specification documents use update operators to specify the data modifications to perform on specific fields during an update operation.

{
  <operator1>: { <field1>: <value1>, ... },
  <operator2>: { <field2>: <value2>, ... },
  ...
}

Index specification documents define the field to index and the index type:

{ <field1>: <type1>, <field2>: <type2>, ...  }