string functions : substr_start and reverse_str
От | PG Explorer |
---|---|
Тема | string functions : substr_start and reverse_str |
Дата | |
Msg-id | 001501c1e3dc$f74e5220$c80ba8c0@sabex.com обсуждение исходный текст |
Ответ на | string functions (April L <april@i-netco.com>) |
Список | pgsql-novice |
Took me 10 min to complete CREATE FUNCTION substr_start(varchar,varchar,int4) RETURNS varchar AS ' DECLARE original alias for $1; substring alias for $2; startpoint alias for $3; return_str varchar; BEGIN return strpos(substr(original,startpoint,length(original)),substring); END;' LANGUAGE 'plpgsql' CREATE FUNCTION reverse_str(varchar) RETURNS varchar AS ' DECLARE original alias for $1; reverse_str varchar; i int4; BEGIN reverse_str = ''''; FOR i IN REVERSE LENGTH(original)..1 LOOP reverse_str = reverse_str || substr(original,i,1); END LOOP; return reverse_str; END;' LANGUAGE 'plpgsql'; http://www.pgexplorer.com GUI postgresql tool ----- Original Message ----- From: "April L" <april@i-netco.com> To: <pgsql-novice@postgresql.org> Sent: Sunday, April 14, 2002 7:02 PM Subject: [NOVICE] string functions > I have studied the Users Lounge and links off of it, looking for a place > where PG users are sharing extended functions they have created for PG. > > In particular I am looking for string functions such as being able to > specify a start point for finding a substring within a string. The existing > PGSQL function position(substring,string) nor strpos(string,substring) have > the option of specifying a start point for the search. > > Also I am looking for a function to reverse a string, so that for example > reverse("april") returns "lirpa" > > Can anyone point me to an area where users are sharing functions they > created, especially the ones I'm looking for? At this point I'm not able to > write one for myself. I am stuck using Cold Fusion which does include the > functions I need, but is so slow at it that it times out before completing > the update to all of my 250,000 records. > > Thank you, > > - April > > > > ---------------------------(end of broadcast)--------------------------- > TIP 2: you can get off all lists at once with the unregister command > (send "unregister YourEmailAddressHere" to majordomo@postgresql.org)
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