strings.out

来自「postgresql8.3.4源码,开源数据库」· OUT 代码 · 共 1,243 行 · 第 1/3 页

--
-- 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'"
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', E'(\\d{3})(\\d{3})(\\d{4})', E'(\\1) \\2-\\3');
 regexp_replace 
----------------
 [phone]
(1 row)

SELECT regexp_replace('AAA   BBB   CCC   ', E'\\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 regexp option
SELECT regexp_replace('AAA aaa', 'A+', 'Z', 'z');
ERROR:  invalid regexp option: "z"
-- set so we can tell NULL from empty string
\pset null '\\N'
-- return all matches from regexp
SELECT regexp_matches('foobarbequebaz', $re$(bar)(beque)$re$);
 regexp_matches 
----------------
 {bar,beque}
(1 row)

-- test case insensitive
SELECT regexp_matches('foObARbEqUEbAz', $re$(bar)(beque)$re$, 'i');
 regexp_matches 
----------------
 {bAR,bEqUE}
(1 row)

-- global option - more than one match
SELECT regexp_matches('foobarbequebazilbarfbonk', $re$(b[^b]+)(b[^b]+)$re$, 'g');
 regexp_matches 
----------------
 {bar,beque}
 {bazil,barf}
(2 rows)

-- empty capture group (matched empty string)
SELECT regexp_matches('foobarbequebaz', $re$(bar)(.*)(beque)$re$);
 regexp_matches 
----------------
 {bar,"",beque}
(1 row)

-- no match
SELECT regexp_matches('foobarbequebaz', $re$(bar)(.+)(beque)$re$);
 regexp_matches 
----------------
(0 rows)

-- optional capture group did not match, null entry in array
SELECT regexp_matches('foobarbequebaz', $re$(bar)(.+)?(beque)$re$);
  regexp_matches  
------------------
 {bar,NULL,beque}
(1 row)

-- no capture groups
SELECT regexp_matches('foobarbequebaz', $re$barbeque$re$);
 regexp_matches 
----------------
 {barbeque}
(1 row)

-- give me errors
SELECT regexp_matches('foobarbequebaz', $re$(bar)(beque)$re$, 'gz');
ERROR:  invalid regexp option: "z"
SELECT regexp_matches('foobarbequebaz', $re$(barbeque$re$);
ERROR:  invalid regular expression: parentheses () not balanced
SELECT regexp_matches('foobarbequebaz', $re$(bar)(beque){2,1}$re$);
ERROR:  invalid regular expression: invalid repetition count(s)
-- split string on regexp
SELECT foo, length(foo) FROM regexp_split_to_table('the quick brown fox jumped over the lazy dog', $re$\s+$re$) AS foo;
  foo   | length 
--------+--------
 the    |      3
 quick  |      5
 brown  |      5
 fox    |      3
 jumped |      6
 over   |      4
 the    |      3
 lazy   |      4
 dog    |      3
(9 rows)

SELECT regexp_split_to_array('the quick brown fox jumped over the lazy dog', $re$\s+$re$);
             regexp_split_to_array              
------------------------------------------------
 {the,quick,brown,fox,jumped,over,the,lazy,dog}
(1 row)

SELECT foo, length(foo) FROM regexp_split_to_table('the quick brown fox jumped over the lazy dog', $re$\s*$re$) AS foo;
 foo | length 
-----+--------
 t   |      1
 h   |      1
 e   |      1
 q   |      1
 u   |      1
 i   |      1
 c   |      1
 k   |      1
 b   |      1
 r   |      1
 o   |      1
 w   |      1
 n   |      1
 f   |      1
 o   |      1
 x   |      1
 j   |      1
 u   |      1
 m   |      1
 p   |      1
 e   |      1
 d   |      1
 o   |      1
 v   |      1
 e   |      1
 r   |      1
 t   |      1
 h   |      1
 e   |      1
 l   |      1
 a   |      1
 z   |      1
 y   |      1
 d   |      1
 o   |      1
 g   |      1
(36 rows)

SELECT regexp_split_to_array('the quick brown fox jumped over the lazy dog', $re$\s*$re$);
                           regexp_split_to_array                           
---------------------------------------------------------------------------
 {t,h,e,q,u,i,c,k,b,r,o,w,n,f,o,x,j,u,m,p,e,d,o,v,e,r,t,h,e,l,a,z,y,d,o,g}
(1 row)

SELECT foo, length(foo) FROM regexp_split_to_table('the quick brown fox jumped over the lazy dog', '') AS foo;
 foo | length 
-----+--------
 t   |      1
 h   |      1
 e   |      1
     |      1
 q   |      1
 u   |      1
 i   |      1
 c   |      1
 k   |      1
     |      1
 b   |      1
 r   |      1
 o   |      1
 w   |      1
 n   |      1
     |      1
 f   |      1
 o   |      1
 x   |      1
     |      1
 j   |      1
 u   |      1
 m   |      1
 p   |      1
 e   |      1
 d   |      1
     |      1
 o   |      1
 v   |      1
 e   |      1
 r   |      1
     |      1
 t   |      1
 h   |      1
 e   |      1
     |      1
 l   |      1
 a   |      1
 z   |      1
 y   |      1
     |      1
 d   |      1
 o   |      1
 g   |      1
(44 rows)

SELECT regexp_split_to_array('the quick brown fox jumped over the lazy dog', '');
                                           regexp_split_to_array                                           
-----------------------------------------------------------------------------------------------------------
 {t,h,e," ",q,u,i,c,k," ",b,r,o,w,n," ",f,o,x," ",j,u,m,p,e,d," ",o,v,e,r," ",t,h,e," ",l,a,z,y," ",d,o,g}
(1 row)

-- case insensitive
SELECT foo, length(foo) FROM regexp_split_to_table('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'i') AS foo;
          foo          | length 
-----------------------+--------
 th                    |      2
  QUick bROWn FOx jUMP |     21
 d ov                  |      4
 r TH                  |      4
  lazy dOG             |      9
(5 rows)

SELECT regexp_split_to_array('thE QUick bROWn FOx jUMPed ovEr THE lazy dOG', 'e', 'i');