Types conversion

Supported type conversions

Primitive types

Nim type	PostgreSQL type	PostgreSQL OID
bool	bool	16
char	char	18
int8	char	18
uint8	char	18
int16	int2	21
uint16	int2	21
int32	int4	23
uint32	int4	23
int64	int8	20
uint64	int8	20
float32	float4	700
float64	float8	701
float	float8	701
int*	int2, int4, int8	21, 23, 20
uint*	int2, int4, int8	21, 23, 20
string	text	25
cstring	text	25

Arrays and Sequences

Nim type	PostgreSQL type	PostgreSQL OID
seq or array of [bool]	ARRAY[bool]	1000
seq or array of [char]	BYTEA	17
seq or array of [int8]	BYTEA	17
seq or array of [uint8]	BYTEA	17
seq or array of [int16]	ARRAY[int2]	1005
seq or array of [uint16]	ARRAY[int2]	1005
seq or array of [int32]	ARRAY[int4]	1007
seq or array of [uint32]	ARRAY[int4]	1007
seq or array of [int64]	ARRAY[int8]	1016
seq or array of [uint64]	ARRAY[uint8]	1016
seq or array of [float32]	ARRAY[float4]	1021
seq or array of [float64]	ARRAY[float8]	1022
seq or array of [float]	ARRAY[float8]	1022
seq or array of [int]*	ARRAY[int2, int4, int8]	1005, 1007, 1016
seq or array of [uint]*	ARRAY[int2, int4, int8]	1005, 1007, 1016
seq or array of [string]	ARRAY[text]	1009
seq or array of [cstring]	ARRAY[text]	1009

• Size of int/uint types in Nim language depends on platform architecture, so if your platform 64bit, int/uint will be converted to PostgreSQL's type int8, if your platform 32bit, int/uint will be converted to PosgreSQL's type int4 and if your platform supports only 16bit integers, int/uint will be converted to PostgreSQL's type int2.

Custom types

Nim type	PostgreSQL type	PostgreSQL OID
JsonNode	json	114
Json*	json	114
JsonB*	jsonb	3802

• Json and JsonB types declared only to allow simple conversion of Nim's JsonNode object to PostgreSQL's json (114) and jsonb (3802) respectively. So you can use Json(JsonNode) to store JsonNode object as PostgreSQL's json object, or JsonB(JsonNode) to store JsonNode object as PostgreSQL's jsonb object.