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|
--
-- TEXT
--
SELECT text 'this is a text string' = text 'this is a text string' AS true;
true
------
t
(1 row)
SELECT text 'this is a text string' = text 'this is a text strin' AS false;
false
-------
f
(1 row)
CREATE TABLE TEXT_TBL (f1 text);
INSERT INTO TEXT_TBL VALUES ('doh!');
INSERT INTO TEXT_TBL VALUES ('hi de ho neighbor');
SELECT '' AS two, * FROM TEXT_TBL;
two | f1
-----+-------------------
| doh!
| hi de ho neighbor
(2 rows)
-- As of 8.3 we have removed most implicit casts to text, so that for example
-- this no longer works:
select length(42);
ERROR: function length(integer) does not exist
LINE 1: select length(42);
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
-- But as a special exception for usability's sake, we still allow implicit
-- casting to text in concatenations, so long as the other input is text or
-- an unknown literal. So these work:
select 'four: '::text || 2+2;
?column?
----------
four: 4
(1 row)
select 'four: ' || 2+2;
?column?
----------
four: 4
(1 row)
-- but not this:
select 3 || 4.0;
ERROR: operator does not exist: integer || numeric
LINE 1: select 3 || 4.0;
^
HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.
/*
* various string functions
*/
select concat('one');
concat
--------
one
(1 row)
select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
concat
----------------------
123hellotf03-09-2010
(1 row)
select concat_ws('#','one');
concat_ws
-----------
one
(1 row)
select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
concat_ws
----------------------------
1#2#3#hello#t#f#03-09-2010
(1 row)
select concat_ws(',',10,20,null,30);
concat_ws
-----------
10,20,30
(1 row)
select concat_ws('',10,20,null,30);
concat_ws
-----------
102030
(1 row)
select concat_ws(NULL,10,20,null,30) is null;
?column?
----------
t
(1 row)
select reverse('abcde');
reverse
---------
edcba
(1 row)
select i, left('ahoj', i), right('ahoj', i) from generate_series(-5, 5) t(i) order by i;
i | left | right
----+------+-------
-5 | |
-4 | |
-3 | a | j
-2 | ah | oj
-1 | aho | hoj
0 | |
1 | a | j
2 | ah | oj
3 | aho | hoj
4 | ahoj | ahoj
5 | ahoj | ahoj
(11 rows)
select quote_literal('');
quote_literal
---------------
''
(1 row)
select quote_literal('abc''');
quote_literal
---------------
'abc'''
(1 row)
select quote_literal(e'\\');
quote_literal
---------------
E'\\'
(1 row)
/*
* format
*/
select format(NULL);
format
--------
(1 row)
select format('Hello');
format
--------
Hello
(1 row)
select format('Hello %s', 'World');
format
-------------
Hello World
(1 row)
select format('Hello %%');
format
---------
Hello %
(1 row)
select format('Hello %%%%');
format
----------
Hello %%
(1 row)
-- should fail
select format('Hello %s %s', 'World');
ERROR: too few arguments for format
select format('Hello %s');
ERROR: too few arguments for format
select format('Hello %x', 20);
ERROR: unrecognized conversion specifier "x"
-- check literal and sql identifiers
select format('INSERT INTO %I VALUES(%L,%L)', 'mytab', 10, 'Hello');
format
----------------------------------------
INSERT INTO mytab VALUES('10','Hello')
(1 row)
select format('%s%s%s','Hello', NULL,'World');
format
------------
HelloWorld
(1 row)
select format('INSERT INTO %I VALUES(%L,%L)', 'mytab', 10, NULL);
format
-------------------------------------
INSERT INTO mytab VALUES('10',NULL)
(1 row)
select format('INSERT INTO %I VALUES(%L,%L)', 'mytab', NULL, 'Hello');
format
----------------------------------------
INSERT INTO mytab VALUES(NULL,'Hello')
(1 row)
-- should fail, sql identifier cannot be NULL
select format('INSERT INTO %I VALUES(%L,%L)', NULL, 10, 'Hello');
ERROR: null values cannot be formatted as an SQL identifier
-- check positional placeholders
select format('%1$s %3$s', 1, 2, 3);
format
--------
1 3
(1 row)
select format('%1$s %12$s', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12);
format
--------
1 12
(1 row)
-- should fail
select format('%1$s %4$s', 1, 2, 3);
ERROR: too few arguments for format
select format('%1$s %13$s', 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12);
ERROR: too few arguments for format
select format('%1s', 1);
ERROR: unterminated conversion specifier
select format('%1$', 1);
ERROR: unterminated conversion specifier
select format('%1$1', 1);
ERROR: unrecognized conversion specifier "1"
--checkk mix of positional and ordered placeholders
select format('Hello %s %1$s %s', 'World', 'Hello again');
format
-------------------------------
Hello World World Hello again
(1 row)
select format('Hello %s %s, %2$s %2$s', 'World', 'Hello again');
format
--------------------------------------------------
Hello World Hello again, Hello again Hello again
(1 row)
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