8. 資料型別
Table 8.1 列出所有內建的通用資料型別。大多數列在「Aliases」中的替代名稱是由於在 PostgreSQL 內部使用的歷史因素。此外,還有一些內部使用或不建議使用的資料型別,但這裡並沒有列出。
Table 8.1. Data Types
Name | Aliases | Description |
---|---|---|
bigint | int8 | signed eight-byte integer |
bigserial | serial8 | autoincrementing eight-byte integer |
bit [ (n ) ] | | fixed-length bit string |
bit varying [ (n ) ] | varbit | variable-length bit string |
boolean | bool | logical Boolean (true/false) |
box | | rectangular box on a plane |
bytea | | binary data (“byte array”) |
character [ (n ) ] | char [ (n ) ] | fixed-length character string |
character varying [ (n ) ] | varchar [ (n ) ] | variable-length character string |
cidr | | IPv4 or IPv6 network address |
circle | | circle on a plane |
date | | calendar date (year, month, day) |
double precision | float8 | double precision floating-point number (8 bytes) |
inet | | IPv4 or IPv6 host address |
integer | int ,int4 | signed four-byte integer |
interval [fields ] [ (p ) ] | | time span |
json | | textual JSON data |
jsonb | | binary JSON data, decomposed |
line | | infinite line on a plane |
lseg | | line segment on a plane |
macaddr | | MAC (Media Access Control) address |
macaddr8 | | MAC (Media Access Control) address (EUI-64 format) |
money | | currency amount |
numeric [ (p ,s ) ] | decimal [ (p ,s ) ] | exact numeric of selectable precision |
path | | geometric path on a plane |
pg_lsn | | PostgreSQLLog Sequence Number |
point | | geometric point on a plane |
polygon | | closed geometric path on a plane |
real | float4 | single precision floating-point number (4 bytes) |
smallint | int2 | signed two-byte integer |
smallserial | serial2 | autoincrementing two-byte integer |
serial | serial4 | autoincrementing four-byte integer |
text | | variable-length character string |
time [ (p ) ] [ without time zone ] | | time of day (no time zone) |
time [ (p ) ] with time zone | timetz | time of day, including time zone |
timestamp [ (p ) ] [ without time zone ] | | date and time (no time zone) |
timestamp [ (p ) ] with time zone | timestamptz | date and time, including time zone |
tsquery | | text search query |
tsvector | | text search document |
txid_snapshot | | user-level transaction ID snapshot |
uuid | | universally unique identifier |
xml | | XML data |
以下資料型別(或其拼寫方式)是由 SQL 指定的:
bigint
,bit
,bit varying
,boolean
,char
,character varying
,character
,varchar
,date
,double precision
,integer
,interval
,numeric
,decimal
,real
,smallint
,time
(with or without time zone),timestamp
(with or without time zone),xml
.每種資料型別都具有其明確的輸入和輸出功能外部表示法。許多內建的資料型別都有明顯的外部格式。但是,有幾種資料型別是 PostgreSQL 獨有的,比如幾何路徑,或者有幾種可能的格式,像是日期和時間型別。某些輸入和輸出功能是不可逆的,意即,與原始輸入相比,輸出功能的結果可能會失去一些精確度。
Last modified 7mo ago