Data Types

This topic describes the mapping between types in the Oracle NoSQL Database and Python data types. The database types are referred to as database types while the Python equivalents are Python types.

Oracle NoSQL Database Types

See Supported Data Types for a description of the data types supported by the service. An application uses these types to create tables and indexes. For example, a table may be created using this Data Definition Language (DDL) statement, which defines types in terms of the database types:

create table mytable(id integer, name string, created timestamp,
    address record(street string, city string, zip integer), primary key(id))

In order to insert rows into such a table your application must create a Python dict that corresponds to that schema, for example:

{'id': 1, 'name': 'myname', 'created': datetime.now(),
 'address' : {'street' : '14 Elm Street', 'city' : 'hometown',
 'zip' : 00000}}

Similarly, when operating on rows retrieved from the database it is important to understand the mappings to Python types.

Mapping Between Database and Python types

These mappings apply on both input (get/query) and output (put). In general the system is permissive in terms of valid conversions among types and that any lossless conversion is allowed. For example an integer will be accepted for a float or double database type. The Timestamp type is also flexible and will accept any valid IS0 8601 formatted string. Timestamps are always stored and managed in UTC.

Database Type	Python Type
Integer	int
Long	int (Python 3), long (Python2)
Float	float
Double	float
Number	decimal.Decimal
Boolean	bool
String	str
Timestamp	datetime.datetime
Enum	str
Binary	bytearray
FixedBinary	bytearray
Array	list
Map	dict
Record	dict
JSON	any Python datatype that can be represented as JSON without data loss

Timestamp in Borneo

As mentioned above Timestamp fields are managed internally as UTC time. If a timezone is supplied when setting a Timestamp, either as a string or as a Python datetime object, it will be honored. The value will be converted to UTC internally and will be in UTC when returned in a row. Although they are represented in UTC returned datetime objects will be “naive” as described by Python documentation. On input, if no timezone is supplied, python datetime instances and time strings are treated as UTC.