strings.out

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

--
-- STRINGS
-- Test various data entry syntaxes.
--
-- SQL92 string continuation syntax
-- E021-03 character string literals
SELECT 'first line'
' - next line'
	' - third line'
	AS "Three lines to one";
         Three lines to one          
-------------------------------------
 first line - next line - third line
(1 row)

-- illegal string continuation syntax
SELECT 'first line'
' - next line' /* this comment is not allowed here */
' - third line'
	AS "Illegal comment within continuation";
ERROR:  syntax error at or near "' - third line'" at character 75
LINE 3: ' - third line'
        ^
--
-- test conversions between various string types
-- E021-10 implicit casting among the character data types
--
SELECT CAST(f1 AS text) AS "text(char)" FROM CHAR_TBL;
 text(char) 
------------
 a
 ab
 abcd
 abcd
(4 rows)

SELECT CAST(f1 AS text) AS "text(varchar)" FROM VARCHAR_TBL;
 text(varchar) 
---------------
 a
 ab
 abcd
 abcd
(4 rows)

SELECT CAST(name 'namefield' AS text) AS "text(name)";
 text(name) 
------------
 namefield
(1 row)

-- since this is an explicit cast, it should truncate w/o error:
SELECT CAST(f1 AS char(10)) AS "char(text)" FROM TEXT_TBL;
 char(text) 
------------
 doh!      
 hi de ho n
(2 rows)

-- note: implicit-cast case is tested in char.sql
SELECT CAST(f1 AS char(20)) AS "char(text)" FROM TEXT_TBL;
      char(text)      
----------------------
 doh!                
 hi de ho neighbor   
(2 rows)

SELECT CAST(f1 AS char(10)) AS "char(varchar)" FROM VARCHAR_TBL;
 char(varchar) 
---------------
 a         
 ab        
 abcd      
 abcd      
(4 rows)

SELECT CAST(name 'namefield' AS char(10)) AS "char(name)";
 char(name) 
------------
 namefield 
(1 row)

SELECT CAST(f1 AS varchar) AS "varchar(text)" FROM TEXT_TBL;
   varchar(text)   
-------------------
 doh!
 hi de ho neighbor
(2 rows)

SELECT CAST(f1 AS varchar) AS "varchar(char)" FROM CHAR_TBL;
 varchar(char) 
---------------
 a
 ab
 abcd
 abcd
(4 rows)

SELECT CAST(name 'namefield' AS varchar) AS "varchar(name)";
 varchar(name) 
---------------
 namefield
(1 row)

--
-- test SQL92 string functions
-- E### and T### are feature reference numbers from SQL99
--
-- E021-09 trim function
SELECT TRIM(BOTH FROM '  bunch o blanks  ') = 'bunch o blanks' AS "bunch o blanks";
 bunch o blanks 
----------------
 t
(1 row)

SELECT TRIM(LEADING FROM '  bunch o blanks  ') = 'bunch o blanks  ' AS "bunch o blanks  ";
 bunch o blanks   
------------------
 t
(1 row)

SELECT TRIM(TRAILING FROM '  bunch o blanks  ') = '  bunch o blanks' AS "  bunch o blanks";
   bunch o blanks 
------------------
 t
(1 row)

SELECT TRIM(BOTH 'x' FROM 'xxxxxsome Xsxxxxx') = 'some Xs' AS "some Xs";
 some Xs 
---------
 t
(1 row)

-- E021-06 substring expression
SELECT SUBSTRING('1234567890' FROM 3) = '34567890' AS "34567890";
 34567890 
----------
 t
(1 row)

SELECT SUBSTRING('1234567890' FROM 4 FOR 3) = '456' AS "456";
 456 
-----
 t
(1 row)

-- T581 regular expression substring (with SQL99's bizarre regexp syntax)
SELECT SUBSTRING('abcdefg' FROM 'a#"(b_d)#"%' FOR '#') AS "bcd";
 bcd 
-----
 bcd
(1 row)

-- No match should return NULL
SELECT SUBSTRING('abcdefg' FROM '#"(b_d)#"%' FOR '#') IS NULL AS "True";
 True 
------
 t
(1 row)

-- Null inputs should return NULL
SELECT SUBSTRING('abcdefg' FROM '(b|c)' FOR NULL) IS NULL AS "True";
 True 
------
 t
(1 row)

SELECT SUBSTRING(NULL FROM '(b|c)' FOR '#') IS NULL AS "True";
 True 
------
 t
(1 row)

SELECT SUBSTRING('abcdefg' FROM NULL FOR '#') IS NULL AS "True";
 True 
------
 t
(1 row)

-- PostgreSQL extension to allow omitting the escape character;
-- here the regexp is taken as Posix syntax
SELECT SUBSTRING('abcdefg' FROM 'c.e') AS "cde";
 cde 
-----
 cde
(1 row)

-- With a parenthesized subexpression, return only what matches the subexpr
SELECT SUBSTRING('abcdefg' FROM 'b(.*)f') AS "cde";
 cde 
-----
 cde
(1 row)

-- PostgreSQL extension to allow using back reference in replace string;
SELECT regexp_replace('1112223333', '(\\d{3})(\\d{3})(\\d{4})', '(\\1) \\2-\\3');
 regexp_replace 
----------------
 [phone]
(1 row)

SELECT regexp_replace('AAA   BBB   CCC   ', '\\s+', ' ', 'g');
 regexp_replace 
----------------
 AAA BBB CCC 
(1 row)

SELECT regexp_replace('AAA', '^|$', 'Z', 'g');
 regexp_replace 
----------------
 ZAAAZ
(1 row)

SELECT regexp_replace('AAA aaa', 'A+', 'Z', 'gi');
 regexp_replace 
----------------
 Z Z
(1 row)

-- invalid option of REGEXP_REPLACE
SELECT regexp_replace('AAA aaa', 'A+', 'Z', 'z');
ERROR:  invalid option of regexp_replace: z
-- E021-11 position expression
SELECT POSITION('4' IN '1234567890') = '4' AS "4";
 4 
---
 t
(1 row)

SELECT POSITION(5 IN '1234567890') = '5' AS "5";
 5 
---
 t
(1 row)

-- T312 character overlay function
SELECT OVERLAY('abcdef' PLACING '45' FROM 4) AS "abc45f";
 abc45f 
--------
 abc45f
(1 row)

SELECT OVERLAY('yabadoo' PLACING 'daba' FROM 5) AS "yabadaba";
 yabadaba 
----------
 yabadaba
(1 row)

SELECT OVERLAY('yabadoo' PLACING 'daba' FROM 5 FOR 0) AS "yabadabadoo";
 yabadabadoo 
-------------
 yabadabadoo
(1 row)

SELECT OVERLAY('babosa' PLACING 'ubb' FROM 2 FOR 4) AS "bubba";
 bubba 
-------
 bubba
(1 row)

--
-- test LIKE
-- Be sure to form every test as a LIKE/NOT LIKE pair.
--
-- simplest examples
-- E061-04 like predicate
SELECT 'hawkeye' LIKE 'h%' AS "true";
 true 
------
 t
(1 row)

SELECT 'hawkeye' NOT LIKE 'h%' AS "false";
 false 
-------
 f
(1 row)

SELECT 'hawkeye' LIKE 'H%' AS "false";
 false 
-------
 f
(1 row)

SELECT 'hawkeye' NOT LIKE 'H%' AS "true";
 true 
------
 t
(1 row)

SELECT 'hawkeye' LIKE 'indio%' AS "false";
 false 
-------
 f
(1 row)

SELECT 'hawkeye' NOT LIKE 'indio%' AS "true";
 true 
------
 t
(1 row)

SELECT 'hawkeye' LIKE 'h%eye' AS "true";
 true 
------
 t
(1 row)

SELECT 'hawkeye' NOT LIKE 'h%eye' AS "false";
 false 
-------
 f
(1 row)

SELECT 'indio' LIKE '_ndio' AS "true";
 true 
------
 t
(1 row)

SELECT 'indio' NOT LIKE '_ndio' AS "false";
 false 
-------
 f
(1 row)

SELECT 'indio' LIKE 'in__o' AS "true";
 true 
------
 t
(1 row)

SELECT 'indio' NOT LIKE 'in__o' AS "false";
 false 
-------
 f
(1 row)

SELECT 'indio' LIKE 'in_o' AS "false";
 false 
-------
 f
(1 row)

SELECT 'indio' NOT LIKE 'in_o' AS "true";
 true 
------
 t
(1 row)

-- unused escape character
SELECT 'hawkeye' LIKE 'h%' ESCAPE '#' AS "true";
 true 
------
 t
(1 row)

SELECT 'hawkeye' NOT LIKE 'h%' ESCAPE '#' AS "false";
 false 
-------
 f
(1 row)

SELECT 'indio' LIKE 'ind_o' ESCAPE '$' AS "true";
 true 
------
 t
(1 row)

SELECT 'indio' NOT LIKE 'ind_o' ESCAPE '$' AS "false";
 false 
-------
 f
(1 row)

-- escape character
-- E061-05 like predicate with escape clause
SELECT 'h%' LIKE 'h#%' ESCAPE '#' AS "true";
 true 
------
 t
(1 row)

SELECT 'h%' NOT LIKE 'h#%' ESCAPE '#' AS "false";
 false 
-------
 f
(1 row)

SELECT 'h%wkeye' LIKE 'h#%' ESCAPE '#' AS "false";
 false 
-------
 f
(1 row)

SELECT 'h%wkeye' NOT LIKE 'h#%' ESCAPE '#' AS "true";
 true 
------
 t
(1 row)

SELECT 'h%wkeye' LIKE 'h#%%' ESCAPE '#' AS "true";
 true 
------
 t
(1 row)

SELECT 'h%wkeye' NOT LIKE 'h#%%' ESCAPE '#' AS "false";
 false 
-------
 f
(1 row)

SELECT 'h%awkeye' LIKE 'h#%a%k%e' ESCAPE '#' AS "true";
 true 
------
 t
(1 row)

SELECT 'h%awkeye' NOT LIKE 'h#%a%k%e' ESCAPE '#' AS "false";
 false 
-------
 f
(1 row)

SELECT 'indio' LIKE '_ndio' ESCAPE '$' AS "true";
 true 
------
 t
(1 row)

SELECT 'indio' NOT LIKE '_ndio' ESCAPE '$' AS "false";
 false 
-------
 f
(1 row)

SELECT 'i_dio' LIKE 'i$_d_o' ESCAPE '$' AS "true";
 true 
------
 t
(1 row)

SELECT 'i_dio' NOT LIKE 'i$_d_o' ESCAPE '$' AS "false";
 false 
-------
 f
(1 row)