「PostgreSQL」FROMのないSELECT文のサンプル

2022年7月13日

環境
Windows 10 home 64bit
Postgresql 9.6.5

使用例
1.数値文字列のselect文

postgres=# select '1' result;

result

--------

(1 行)

postgres=# select '1' result; result -------- 1 (1 行)

postgres=# select '1' result;
 result
--------
 1
(1 行)

2.英数字のselect文

postgres=# select 'bb' as resA,'BB' as resB,'study' as resC;

resa | resb | resc

------+------+-------

bb | BB | study

(1 行)

postgres=# select 'bb' as resA,'BB' as resB,'study' as resC; resa | resb | resc ------+------+------- bb | BB | study (1 行)

postgres=# select 'bb' as resA,'BB' as resB,'study' as resC;
 resa | resb | resc
------+------+-------
 bb   | BB   | study
(1 行)

3.現在日付時刻のselect文

postgres=# select now() result;

result

-------------------------------

2022-07-13 18:48:26.307339+09

(1 行)

postgres=# select now() result; result ------------------------------- 2022-07-13 18:48:26.307339+09 (1 行)

postgres=# select now() result;
            result
-------------------------------
 2022-07-13 18:48:26.307339+09
(1 行)

4.現在のシステム日付を取得します

postgres=# select current_date result;

result

------------

2022-07-13

(1 行)

postgres=# select current_date result; result ------------ 2022-07-13 (1 行)

postgres=# select current_date result;
   result
------------
 2022-07-13
(1 行)

5.cast関数のselect文

postgres=# select cast(4567.22 as integer) result;

result

--------

4567

(1 行)

postgres=# select cast(4567.22 as integer) result; result -------- 4567 (1 行)

postgres=# select cast(4567.22 as integer) result;
 result
--------
   4567
(1 行)

Posted by arkgame