union.sql

关系型数据库 Postgresql 6.5.2

--
-- union.sql
--

-- Simple UNION constructs

SELECT 1 AS two UNION SELECT 2;

SELECT 1 AS one UNION SELECT 1;

SELECT 1 AS two UNION ALL SELECT 2;

SELECT 1 AS two UNION ALL SELECT 1;

SELECT 1 AS three UNION SELECT 2 UNION SELECT 3;

SELECT 1 AS two UNION SELECT 2 UNION SELECT 2;

SELECT 1 AS three UNION SELECT 2 UNION ALL SELECT 2;

SELECT 1.1 AS two UNION SELECT 2.2;

-- Mixed types

SELECT 1.1 AS two UNION SELECT 2;

SELECT 1 AS two UNION SELECT 2.2;

SELECT 1 AS one UNION SELECT 1.1;

SELECT 1.1 AS two UNION ALL SELECT 2;

SELECT 1 AS two UNION ALL SELECT 1;

SELECT 1 AS three UNION SELECT 2 UNION SELECT 3;

SELECT 1 AS two UNION SELECT 2 UNION SELECT 2;

SELECT 1 AS three UNION SELECT 2 UNION ALL SELECT 2;

--
-- Try testing from tables...
--

SELECT f1 AS five FROM FLOAT8_TBL
UNION
SELECT f1 FROM FLOAT8_TBL;

SELECT f1 AS ten FROM FLOAT8_TBL
UNION ALL
SELECT f1 FROM FLOAT8_TBL;

SELECT f1 AS nine FROM FLOAT8_TBL
UNION
SELECT f1 FROM INT4_TBL;

SELECT f1 AS ten FROM FLOAT8_TBL
UNION ALL
SELECT f1 FROM INT4_TBL;

SELECT f1 AS five FROM FLOAT8_TBL
  WHERE f1 BETWEEN -1e6 AND 1e6
UNION
SELECT f1 FROM INT4_TBL
  WHERE f1 BETWEEN 0 AND 1000000;

SELECT f1 AS five FROM VARCHAR_TBL
UNION
SELECT f1 FROM CHAR_TBL;

SELECT f1 AS three FROM VARCHAR_TBL
UNION
SELECT TRIM(TRAILING FROM f1) FROM CHAR_TBL;

SELECT f1 AS eight FROM VARCHAR_TBL
UNION ALL
SELECT f1 FROM CHAR_TBL;

SELECT f1 AS five FROM TEXT_TBL
UNION
SELECT f1 FROM VARCHAR_TBL
UNION
SELECT TRIM(TRAILING FROM f1) FROM CHAR_TBL;