Type mappings

Type mappings when reading values sent from the backend

PostgreSQL type	Default .NET type	Provider-specific type	Other .NET types
bool	bool
int2	short		byte, sbyte, int, long, float, double, decimal, string
int4	int		byte, short, long, float, double, decimal, string
int8	long		long, byte, short, int, float, double, decimal, string
float4	float		double
float8	double
numeric	decimal		byte, short, int, long, float, double, string
money	decimal
text	string		char[]
varchar	string		char[]
bpchar	string		char[]
citext	string		char[]
json	string		char[]
jsonb	string		char[]
xml	string		char[]
point	NpgsqlPoint		string
lseg	NpgsqlLSeg		string
path	NpgsqlPath
polygon	NpgsqlPolygon
line	NpgsqlLine		string
circle	NpgsqlCircle		string
box	NpgsqlBox		string
bit(1)	bool		BitArray
bit(n)	BitArray
varbit	BitArray
hstore	IDictionary<string, string>		string
uuid	Guid		string
cidr	NpgsqlInet		string
inet	IPAddress	NpgsqlInet	string
macaddr	PhysicalAddress		string
tsquery	NpgsqlTsQuery
tsvector	NpgsqlTsVector
date	DateTime	NpgsqlDate
interval	TimeSpan	NpgsqlTimeSpan
timestamp	DateTime	NpgsqlDateTime
timestamptz	DateTime	NpgsqlDateTime	DateTimeOffset
time	TimeSpan
timetz	DateTimeOffset		DateTimeOffset, DateTime, TimeSpan
bytea	byte[]
oid	uint
xid	uint
cid	uint
oidvector	uint[]
name	string		char[]
(internal) char	char		byte, short, int, long
geometry (PostGIS)	PostgisGeometry
record	object[]
composite types	T
range subtypes	NpgsqlRange
enum types	TEnum
array types	Array (of child element type)

有需要的朋友可以去看看。