Overview

Basic data types

Flavius support the following data types:

Data Type	Alias	Description	Storage Size	Min Value	Max Value
BOOLEAN	BOOL	Boolean	1 Byte	N/A	N/A
BIGINT	-	64-bit signed integer	8 Bytes	-9223372036854775808	9223372036854775807
DOUBLE	-	Double precision floating point number	8 Bytes	-1.7976931348623157E+308	1.7976931348623157E+308
VARCHAR	-	UTF-8 valid string	N/A	N/A	N/A
TIME	-	Time with nanosecond precision	8 Bytes	’00:00:00.000000000'	'23:59:59.999999999’
DATE	-	Date in the format ‘YYYY-MM-DD’	4 Bytes	’0001-01-01'	'9999-12-31’
DATETIME	-	Date + Time with nanosecond precision	8 Bytes	’1677-09-21T00:12:44.999999999'	'2262-04-11T23:47:16.854775807’
TIMESTAMP	-	Date + Time with nanosecond precision + timezone	8 Bytes	’1677-09-21T00:12:44.999999999+0000'	'2262-04-11T23:47:16.854775807+0000’

Structured data types

Flavius support the following structured data types:

Data Type	Alias	Description	Example
ARRAY	LIST	Collection of values of the same type	`[1, 2, 3]`, `['a', 'b', 'c']`, `[true, false]`
STRUCT	-	Collection of values of different types	`{name: 'John', age: 30, active: true}`

Graph specific data types

Flavius support the following graph specific data types:

Data Type	Alias	Description	Example
Vertex	-	Vertex/Node structure, has two built in fields, `__id__` of BIGINT type to represent the internal id of this node, `__label__` of VARCHAR type describing the associated node label.	`{name:'John', age: 30, active: true, __id__ : 12345, __label__ : }`
Edge	-	Edge/Relationship structure, has three built-in fields: `__srcid__` of BIGINT type representing the source vertex ID, `__dstid__` of BIGINT type representing the destination vertex ID, and `__label__` of VARCHAR type describing the edge label	`{__srcid__: 1, __dstid__: 2, __label__: "KNOWS", since: "2023"}`

Casting

Casting rules

Flavius supports implicit and explicit type casting between different data types. The following table shows the supported type casting operations:

From Type	To Type	Implicit	Explicit	Notes
BOOLEAN	VARCHAR	✓	✓	Converts to ‘true’ or ‘false’ string
BOOLEAN	BIGINT	✓	✓	Converts to 1 (true) or 0 (false)
BOOLEAN	DOUBLE	✓	✓	Converts to 1.0 (true) or 0.0 (false)
BIGINT	BOOLEAN	✗	✓	Converts to false (0) or true (other values)
BIGINT	DOUBLE	✓	✓	May lose precision
BIGINT	VARCHAR	✗	✓	Converts to string representation
DOUBLE	BOOLEAN	✗	✓	Converts to false (0.0) or true (other values)
DOUBLE	BIGINT	✗	✓	May lose precision
DOUBLE	VARCHAR	✗	✓	Converts to string representation
VARCHAR	BOOLEAN	✗	✓	Only ‘true’/‘false’ (case-insensitive)
VARCHAR	BIGINT	✗	✓	Must be valid integer string
VARCHAR	DOUBLE	✗	✓	Must be valid numeric string
VARCHAR	DATE	✗	✓	Must be in format ‘YYYY-MM-DD’
VARCHAR	TIME	✗	✓	Must be in format ‘HH:MM:SS[.nnnnnnnnn]‘
VARCHAR	DATETIME	✗	✓	Must be in format ‘YYYY-MM-DD HH:MM:SS[.nnnnnnnnn]‘
VARCHAR	TIMESTAMP	✗	✓	Must be in format ‘YYYY-MM-DD HH:MM:SS[.nnnnnnnnn][+-]HH:MM’ or ‘YYYY-MM-DD HH:MM:SS[.nnnnnnnnn][Z]’ , example: `2024-12-23 23:49:23+0800`
TIME	VARCHAR	✗	✓	Converts to ‘YYYY-MM-DD’ format
DATE	VARCHAR	✗	✓	Converts date to string in ‘YYYY-MM-DD’ format
DATE	DATETIME	✓	✓	Adds default time component ‘00:00:00.000000000’ to date
DATE	TIMESTAMP	✓	✓	Adds default time ‘00:00:00.000000000’ and UTC timezone to date
DATETIME	VARCHAR	✗	✓	Converts datetime to string in ‘YYYY-MM-DD[ T]HH:MM:SS[.nnnnnnnnn]’ format
DATETIME	DATE	✗	✓	Extracts date part only
DATETIME	TIMESTAMP	✓	✓	Adds UTC timezone
TIMESTAMP	VARCHAR	✗	✓	Converts timestamp to string in ‘YYYY-MM-DD[ T]HH:MM:SS[.nnnnnnnnn][Z]’ format
TIMESTAMP	DATE	✗	✓	Extracts date part only
TIMESTAMP	DATETIME	✗	✓	Removes timezone information

Explicit casting by `CAST` expression

Syntax


CAST(<value> AS <type>)

Example:


-- Convert string to date
CAST('2023-01-01' AS DATE);
 
-- Convert boolean to integer
CAST(true AS BIGINT);
 
-- Convert datetime to timestamp
CAST('2023-01-01 12:00:00' AS TIMESTAMP);
 
-- Convert array of strings to array of integers
CAST(['1', '2', '3'] AS ARRAY<BIGINT>);