SQL Server 与 PostgreSQL 数据类型映射关系

	Microsoft SQL Server	PostgreSQL
BIGINT	64-bit integer	BIGINT
BINARY(n)	Fixed length byte string	BYTEA
BIT	1, 0 or NULL	BOOLEAN
CHAR(n)	Fixed length char string, 1 <= n <= 8000	CHAR(n)
VARCHAR(n)	Variable length char string, 1 <= n <= 8000	VARCHAR(n)
VARCHAR(max)	Variable length char string, <= 2GB	TEXT
VARBINARY(n)	Variable length byte string , 1 <= n <= 8000	BYTEA
VARBINARY(max)	Variable length byte string , <= 2GB	BYTEA
NVARCHAR(n)	Variable length Unicode UCS-2 string	VARCHAR(n)
NVARCHAR(max)	Variable length Unicode UCS-2 data, <= 2GB	TEXT
TEXT	Variable length character data, <= 2GB	TEXT
NTEXT	Variable length Unicode UCS-2 data, <= 2GB	TEXT
DOUBLE PRECISION	Double precision floating point number	DOUBLE PRECISION
FLOAT§	Floating point number	DOUBLE PRECISION
INTEGER	32 bit integer	INTEGER
NUMERIC(p,s)	Fixed point number	NUMERIC(p,s)
DATE	Date includes year, month and day	DATE
DATETIME	Date and Time with fraction	TIMESTAMP(3)
DATETIME2§	Date and Time with fraction	TIMESTAMP(n)
DATETIMEOFFSET§	Date and Time with fraction and time zone	TIMESTAMP§ WITH TIME ZONE
SMALLDATETIME	Date and Time	TIMESTAMP(0)
TINYINT	8 bit unsigned integer, 0 to 255	SMALLINT
UNIQUEIDENTIFIER	16 byte GUID(UUID) data	CHAR(16)
ROWVERSION	Automatically updated binary data	BYTEA
SMALLMONEY	32 bit currency amount	MONEY
IMAGE	Variable length binary data, <= 2GB	BYTEA

以下在实际项目中应用的，可作参考，如果有纰漏麻烦指正！

• datetime 改为 timestamp(0)
• int 改为 int8
• chinese_prc_ci_as 改为 “pg_catalog”.“default”
• float(53) 改为 decimal(35,15)
• nvarchar 改为 varchar