Data Types and Forms

Data Type Mappings

The following table shows the mapping between data types in C++ and their corresponding data types in DolphinDB (“-“ indicates that there is no matching C++ data type).


Category	DolphinDB Data Type	DolphinDB Example	C++ Underlying Type	C++ Example	C++ API Type	Example for Converting Between C++ Primitive and API Type
NUMERIC	BOOL	false	char	0	Bool	ConstantSP data = new Bool(true); bool value = data->getBool();
	CHAR	’a'	char	'a'	Char	ConstantSP data = new Char('a'); char value = data->getChar();
	SHORT	122h	short	122	Short	ConstantSP data = new Short(122); short value = data->getShort();
	INT	21	int	21	Int	ConstantSP data = new Int(21); int value = data->getInt();
	LONG	22l	long long	22	Long	ConstantSP data = new Long(22); long long value = data->getLong();
	FLOAT	2.1f	float	2.1f	Float	ConstantSP data = new Float(2.1f); float value = data->getFloat();
	DOUBLE	2.2	double	2.2	Double	ConstantSP data = new Double(2.2); double value = data->getDouble();
	DECIMAL32	decimal32(2.1, 3)	int	2100	Decimal32	ConstantSP data = new Decimal32(2, 2); double value = data->getDouble();
	DECIMAL64	decimal64(2.1, 3)	long	2100	Decimal64	ConstantSP data = new Decimal64(8, 8); double value = data->getDouble();
	DECIMAL128	decimal128(2.1, 3)	int128	2100	Decimal128	ConstantSP data = new Decimal128(18, 18); double value = data->getDouble();
TEMPORAL	DATE	2013.06.13	int	15869	Date	ConstantSP data = new Date(2013, 6, 13); int value = data->getInt();
	MONTH	2012.06M	int	24149	Month	ConstantSP data = new Month(2012, 6); int value = data->getInt();
	TIME	13:30:10.008	int	48610008	Time	ConstantSP data = new Time(13, 30, 10, 8); int value = data->getInt();
	MINUTE	13:30m	int	810	Minute	ConstantSP data = new Minute(13, 30); int value = data->getInt();
	SECOND	13:30:10	int	48610	Second	ConstantSP data = new Second(13, 30, 10); int value = data->getInt();
	DATETIME	2012.06.13 13:30:10	int	1339594210	DateTime	ConstantSP data = new DateTime(2012, 6, 13, 13, 30, 10); int value = data->getInt();
	DATEHOUR	2012.06.13T13	int	372109	DateHour	ConstantSP data = new DateHour(2012, 6, 13, 13); int value = data->getInt();
	TIMESTAMP	2012.06.13 13:30:10.008	long long	1339594210008	Timestamp	ConstantSP data = new Timestamp(2012, 6, 13, 13, 30, 10, 8); long long value = data->getLong();
	NANOTIME	13:30:10.008007006	long long	48610008007006	NanoTime	ConstantSP data = new NanoTime(13, 30, 10, 8007006); long long value = data->getLong();
	NANOTIMESTAMP	2012.06.13 13:30:10.008007006	long long	1339594210008007006	NanoTimestamp	ConstantSP data = new NanoTimestamp(2012, 6, 13,13, 30, 10, 8007006); long long value = data->getLong();
LITERAL	STRING	“Hello”	std::string	“Hello”	String	ConstantSP data = new String("Hello"); std::string value = data->getString();
	SYMBOL	“Hello”	-	-	-	-
	BLOB	“Hello”	std::string	“Hello”	String	ConstantSP data = new String("Hello", true); std::string value = data->getString();
OTHER	UUID	5d212a78-cc48-e3b1-4235-b4d91473ee87	unsigned char[16]	-	Uuid	ConstantSP data = new Uuid(true); std::string value = data->getString();
	INT128	e1671797c52e15f763380b45e841ec32	unsigned char[16]	-	Int128	ConstantSP data = new Int128(); std::string value = data->getString();
	IPADDR	192.168.1.13	unsigned char[16]	-	IPAddr	ConstantSP data = new IPAddr(); std::string value = data->getString();
	VOID	NULL	-	-	Void	ConstantSP data = new Void();

Supported Data Forms

The DolphinDB C++ API supports various data forms, which are listed below with examples of DolphinDB data forms.


Data Form	Description	DolphinDB Example
scalar	a variable that holds one value at a time	5, 1.3, 2012.11.15, `hello
vector	a container that holds a list of objects in a given order	[1,2,3,4,5,6,7,8,9,10]
array vector	a two-dimensional vector where each row is a variable-length vector	[[1,2,3],[4,5],[6,7,8],[9,10]]
matrix	a one-dimensional array with column major	matrix([1 2 3, 4 5 6]);
set	a container that holds a list of unsorted objects with no duplicate values	(2,5)
dictionary	a container that holds a list of unique key-value pairs	(1->4.5, 2->7.8, 3->4.3)
table	a database object that holds a list of vectors in a given order	-