附录1：各种数据库支持的数据类型

注：以下为各数据库支持的数据类型，出现在表中的类型代表均支持单值，数组（ARRAY）和区间（INTERVAL）用“✓”和“✗”代表是否支持

Postgres/Greenplum/Gaussdb

数据类型	是否支持单值	是否支持 ARRAY	是否支持 INTERVAL	备注
text	✓	✓	✗
character varying	✓	✓	✗	varchar
character	✓	✓	✗	bpchar
timestamp with time zone	✓	✓	✗	timestamptz
timestamp without time zone	✓	✓	✗	timestamp
uuid	✓	✓	✗
real	✓	✓	✗	float4
double precision	✓	✓	✗	float8
smallint	✓	✓	✗	int2
date	✓	✓	✗
money	✓	✓	✗
integer	✓	✓	✗	int4
macaddr	✓	✓	✗
macaddr8	✓	✓	✗
numeric	✓	✓	✗
bigint	✓	✓	✗	int8
cidr	✓	✓	✗

查询属性类型的sql语句： select data_type from information_schema."columns" c where table_name = ''

数据类型	是否支持单值	是否支持 ARRAY	是否支持 INTERVAL
int	✓	✗	✗
tinyint	✓	✗	✗
smallint	✓	✗	✗
mediumint	✓	✗	✗
bigint	✓	✗	✗
float	✓	✗	✗
double	✓	✗	✗
decimal	✓	✗	✗
char	✓	✗	✗
varchar	✓	✗	✗
text	✓	✗	✗
tinytext	✓	✗	✗
longtext	✓	✗	✗
mediumtext	✓	✗	✗
year	✓	✗	✗
date	✓	✗	✗
datetime	✓	✗	✗
timestamp	✓	✗	✗

查询属性类型的sql语句： select COLUMN_NAME, DATA_TYPE from information_schema.columns where table_schema = '' and table_name = ''

数据类型	是否支持单值	是否支持 ARRAY	是否支持 INTERVAL	备注
INTERGER	✓	✗	✗
SMALLINT	✓	✗	✗
LONG	✓	✗	✗
NUMBER	✓	✗	✗
FLOAT	✓	✗	✗
CHAR	✓	✗	✗
NCHAR	✓	✗	✗
VARCHAR	✓	✗	✗
NVARCHAR	✓	✗	✗
VARCHAR2	✓	✗	✗
NVARCHAR2	✓	✗	✗
DATE	✓	✗	✗
TIMESTAMP(6)	✓	✗	✗	默认的timestamp类型

查询属性类型的sql语句：SELECT COLUMN_NAME, DATA_TYPE FROM all_tab_columns WHERE OWNER = '' AND TABLE_NAME = ''

数据类型	是否支持单值	是否支持 ARRAY	是否支持 INTERVAL
int	✓	✓	✗
tinyint	✓	✓	✗
smallint	✓	✓	✗
bigint	✓	✓	✗
float	✓	✓	✗
double	✓	✓	✗
decimal	✓	✓	✗
char	✓	✓	✗
string	✓	✓	✗
varchar	✓	✓	✗
date	✓	✓	✗
timestamp	✓	✓	✗

查询属性类型的sql语句： desc ``.`` （此处是反引号）