I finish devel. of Oracle compatible DateTime routines TO_CHAR(),

TO_DATE()
and PgSQL extension FROM_CHAR().

TO_CHAR() routine allow formating text output with a datetime values:

        SELECT TO_CHAR('now'::datetime, '"Now is: "HH24:MI:SS');
        to_char
        ----------------
        Now is: 21:04:10

FROM_CHAR() routine allow convert text to a datetime:

        SELECT FROM_CHAR('September 1999 10:20:30', 'FMMonth YYYY
HH:MI:SS');
        from_char
        -----------------------------
        Wed Sep 01 10:20:30 1999 CEST

TO_DATE() is equal with FROM_CHAR(), but output a Date only:

        SELECT TO_DATE('September 1999 10:20:30', 'FMMonth YYYY
HH:MI:SS');
        to_date
        ----------
        09-01-1999


In attache is compressed dir for the contrib. All is prepared, but I'am
not
sure if Makefile is good (probably yes).

Comments & suggestions ?


Thomas, thank you for your good advices.

                                                        Karel


------------------------------------------------------------------------------

Karel Zak <zakkr@zf.jcu.cz>
http://home.zf.jcu.cz/~zakkr/

contrib/README

@@ -10,6 +10,14 @@ array -
 	Array iterator functions
 	by Massimo Dal Zotto <dz@cs.unitn.it>
 
+bit -
+	Bit type
+	by Adriaan Joubert <a.joubert@albourne.com>
+
+dateformat -
+	Date Formatting to/from character strings
+	by Karel Zak - Zakkr <zakkr@zf.jcu.cz>
+
 datetime -
 	Date & time functions
 	by Massimo Dal Zotto <dz@cs.unitn.it>

contrib/dateformat/Makefile

+#-------------------------------------------------------------------------
+#
+# Makefile --
+#
+#    Makefile for TO-FROM_CHAR module.
+#
+#-------------------------------------------------------------------------
+
+PGDIR = ../..
+SRCDIR = $(PGDIR)/src
+
+include $(SRCDIR)/Makefile.global
+
+INCLUDE_OPT =	-I ./ \
+		-I $(SRCDIR)/ \
+		-I $(SRCDIR)/include \
+		-I $(SRCDIR)/port/$(PORTNAME)
+
+CFLAGS += $(INCLUDE_OPT) $(CFLAGS_SL)
+
+MODNAME =	to-from_char
+
+SQLDEFS =	$(MODNAME).sql
+
+MODULE =	$(MODNAME)$(DLSUFFIX)
+
+MODDIR =	$(LIBDIR)/modules
+
+SQLDIR =	$(LIBDIR)/sql
+
+all:		module sql
+
+module:		$(MODULE)
+
+sql:		$(SQLDEFS)
+
+install:	$(MODULE) $(SQLDEFS) $(MODDIR) $(SQLDIR)
+		cp -p $(MODULE) $(MODDIR)/
+		strip $(MODDIR)/$(MODULE)
+		cp -p $(SQLDEFS) $(SQLDIR)/
+
+install-doc:	
+		if [ -d "$(DOCDIR)" ]; then \
+		    cp -p *.doc $(DOCDIR); \
+		else \
+		    cp -p *.doc $(SQLDIR); \
+		fi
+
+$(MODDIR):
+		mkdir -p $@
+
+$(SQLDIR):
+		mkdir -p $@
+
+%.sql: %.sql.in
+		sed "s|MODULE_PATHNAME|$(MODDIR)/$(MODULE)|" < $< > $@
+
+.SUFFIXES: $(DLSUFFIX)
+
+%$(DLSUFFIX): %.c
+		$(CC) $(CFLAGS) -shared -o $@ $<
+
+depend dep:
+		$(CC) -MM $(INCLUDE_OPT) *.c >depend
+
+clean:
+		rm -f *~ $(MODULE) $(MODNAME).sql
+
+ifeq (depend,$(wildcard depend))
+include depend
+endif

contrib/dateformat/test/Makefile

+
+PROGRAM	= rand_datetime
+	
+OBJECTS	= rand_datetime.o
+
+CFLAGS 	= -Wall -fpic -O3
+CC	= gcc
+RM	= rm -f
+LIBS	=
+INCLUDE	=
+
+COMPILE = $(CC) $(CPPFLAGS) $(CFLAGS) $(INCLUDE)
+LINK    = $(CC) $(CFLAGS) -o $@ $(LIBS)
+
+
+all: $(PROGRAM) 	
+
+$(PROGRAM): $(OBJECTS)
+	$(LINK) $(OBJECTS)
+
+.c.o: $<
+	$(COMPILE) -c $<
+
+clean:
+	$(RM) -f *~ $(OBJECTS) $(PROGRAM)

contrib/dateformat/test/README

+
+	TO/FROM CHAR tests
+	~~~~~~~~~~~~~~~~~~
+
+ * rand_datetime
+
+	The program 'rand_datetime' output a random datetime strings 
+	(with yaer range 0..9999), you can use this for datetime testing.
+
+	You can usage this (example) for table filling.
+
+	Usage:
+	
+	./rand_datetime <randfile> <num> <prefix> <postfix>
+	
+	Example:
+	
+	./rand_datetime /dev/urandom 2 "INSERT INTO tab VALUES('" "'::datetime);"
+
+	INSERT INTO tab VALUES('Sat 27 Jul 13:08:57 19618'::datetime);
+	INSERT INTO tab VALUES('Wed 25 Aug 20:31:50 27450'::datetime);  
+
+ * regress
+	
+	psql < regress.sql	(all answers, must be TRUE, for Posgres
+                                 datestyle)
+	
+	
+	--> TO_DATE() is simular as FROM_CHAR(), but convert full datetime
+	    to date ==> needn't test (?).
+ 
+
+

contrib/dateformat/test/rand_datetime.c

+
+#include <stdio.h>
+#include <errno.h>
+#include <ctype.h>
+#include <stdlib.h>
+
+
+char	*month[]	= {
+	"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec",NULL        
+};
+
+char	*day[] = { "Sun","Mon","Tue","Wed","Thu","Fri","Sat", NULL };
+
+int num(FILE *f, int min, int max)
+{
+	int	x, y, one;
+	
+	one = x = fgetc(f);
+	
+	
+	if (x < min)
+		x = min;	
+	else if (x > max) {
+		while(x > max)
+			x /= 2;	 
+		return x;
+	}
+	
+	do {
+		y = fgetc(f);
+		if ((x+y) > max)
+			return x;
+		x += y;
+	} while(--one > 0);
+	
+	return x;	
+}
+
+int main(int argc, char **argv)
+{
+	FILE	*f; 
+	int	count;
+	
+	if (argc < 5) {
+		printf("\nUsage: %s <randfile> <num> <prefix> <postfix>\n", argv[0]);
+		printf("\n(C) Karel Zak - Zakkr 1999\n\n");
+		exit(1);
+	}
+	
+	if ((f = fopen(argv[1], "r")) == NULL) {
+		perror(argv[1]);
+		exit(1);
+	}
+
+	count = atoi(argv[2]);
+	
+	for(; count > 0; --count) {
+		fprintf(stdout, "%s%s %02d %s %02d:%02d:%02d %d%s\n",
+			argv[3],
+			day[ num(f, 0, 6) ],
+			num(f, 1, 28),
+			month[ num(f, 0, 11) ],	
+			num(f, 0, 23),
+			num(f, 0, 59),
+			num(f, 0, 59),
+			num(f, 0, 9999),
+			argv[4]
+		);	
+	}	
+	exit(0);
+}
\ No newline at end of file

contrib/dateformat/test/regress.sql

+
+---
+--- Postgres DateStyle needs all tests which parsing 'now'::datetime string
+---
+SET DATESTYLE TO 'Postgres';
+
+
+SELECT 'now'::datetime = 
+	TO_CHAR('now'::datetime, 'Dy Mon DD HH24:MI:SS YYYY')::datetime 
+as "Now vs. to_char";	
+
+	
+SELECT 'now'::datetime = 
+	FROM_CHAR('now'::datetime, 'Dy Mon DD HH24:MI:SS YYYY')
+as "Now vs. from_char";
+
+
+SELECT	FROM_CHAR('now'::datetime, 'Dy Mon DD HH24:MI:SS YYYY') = 
+	TO_CHAR('now'::datetime, 'Dy Mon DD HH24:MI:SS YYYY')::datetime 
+as "From_char vs. To_char";	
+	
+
+SELECT 'now'::datetime = 	
+	FROM_CHAR( 
+		TO_CHAR('now'::datetime, '"Time: "HH24-MI-SS" Date: "Dy DD Mon YYYY'),
+		'"Time: "HH24-MI-SS" Date: "Dy DD Mon YYYY'
+	)
+as "High from/to char test"; 	
+
+
+SELECT TO_CHAR('now'::datetime, 'SSSS')::int = 
+		TO_CHAR('now'::datetime, 'HH24')::int * 3600 + 
+		TO_CHAR('now'::datetime, 'MI')::int * 60 + 
+		TO_CHAR('now'::datetime, 'SS')::int
+as "SSSS test";
+
+
+SELECT TO_CHAR('now'::datetime, 'WW')::int =
+		(TO_CHAR('now'::datetime, 'DDD')::int -
+		TO_CHAR('now'::datetime, 'D')::int + 7) / 7 
+as "Week test";	
+	 
+
+SELECT TO_CHAR('now'::datetime, 'Q')::int =
+		TO_CHAR('now'::datetime, 'MM')::int / 3 + 1
+as "Quartal test";
+
+
+SELECT TO_CHAR('now'::datetime, 'DDD')::int =
+	(TO_CHAR('now'::datetime, 'WW')::int * 7) -  
+	(7 - TO_CHAR('now'::datetime, 'D')::int) +
+	(7 - TO_CHAR(('01-Jan-'|| 
+		TO_CHAR('now'::datetime,'YYYY'))::datetime,'D')::int)
+	+1
+as "Week and day test";
+
+
+

contrib/dateformat/to-from_char.doc

+
+
+ TO_CHAR(datetime, text)	
+ ----------------------- 	
+	  (returns text) 	   
+
+ 	TO_CHAR - the DateTime function for formating date and time outputs. 
+        This routine is inspire with the Oracle to_char().  
+	
+	SELECT TO_CHAR('now'::datetime, 'HH:MI:SS YYYY');
+	-------------
+	11:57:11 1999
+
+
+ FROM_CHAR(text, text) 		
+ ---------------------
+    (returns DateTime)
+
+	FROM_CHAR - the PostgreSQL extension routine which read non-datetime
+        string and convert it to DateTime. This func. is inspire with the 
+	Oracle to_date() routine, but in Oracle this func. return date only
+	and not support all keywords (format pictures).
+
+	SELECT FROM_CHAR('11:57:11 1999', 'HH:MI:SS YYYY');
+	----------------------------
+	Fri 01 Jan 11:57:11 1999 CET
+
+
+ TO_DATE(text, text) 		
+ -------------------
+      (returns Date)
+ 
+	TO_DATE - the Date function which read non-datetime (non-date) string
+	and convert it to date. All for thos func. is just as from_char().
+	This func. is inspire with the Oracle to_date() routine.
+
+	SELECT TO_DATE('11:57:11 1999', 'HH:MI:SS YYYY');
+	----------
+	01-01-1999
+
+
+
+ ----------------------------------
+ String format-KeyWords and options: 
+ ----------------------------------
+
+	* TO_CHAR   (..., 'format picture')
+	* FROM_CHAR (..., 'format picture')	
+	* TO_DATE   (..., 'format picture')
+
+	(Note: In Oracle manual is format-keyword called 'format pictures'.)     
+
+	All keywords has suffixes (prefix or postfix), example for 2 hours:	
+		keyword: HH	(hour)		  'HH'     --> '02'
+		prefix:	 FM	(fill mode)	  'FMHH'   --> '2'
+		postfix: TH	(ordinal number)  'HHth'   --> '02nd'
+						  'FMHHth' --> '2nd'	
+
+	Suffixes:
+        --------
+		FM - fill mode
+			02        --> FMHH	--> 2		
+			January , --> FMMonth	--> January,
+			
+		TH - upper ordinal number
+			02	  --> HHTH	--> 02ND
+		
+		th - lower ordinal number
+			02	  --> HHth	--> 02th			
+
+
+	KeyWords (format pictures):
+	--------------------------	
+
+		HH 	- hour of day (01-12)
+	 	HH12	-  -- // --
+	 	HH24	- hour (00-24)
+	 	MI	- minute (00-59)
+	 	SS	- socond (00-59)
+	 	SSSS	- seconds past midnight (0-86399)	
+	 	Y,YYY	- year with comma (full PgSQL datetime range) digits) 
+	 	YYYY	- year (4 and more (full PgSQL datetime range) digits) 
+	 	YYY	- last 3 digits of year 
+	 	YY	- last 2 digits of year 
+	 	Y	- last digit of year 
+	 	MONTH	- full month name (upper) (9-letters)
+	 	Month	- full month name - first character is upper (9-letters)
+	 	month	- full month name - all characters is upper (9-letters) 
+		MON	- abbreviated month name (3-letters)
+		Mon	- abbreviated month name (3-letters) - first character is upper 
+		mon	- abbreviated month name (3-letters) - all characters is upper 
+		MM	- month (01-12)
+	 	DAY	- full day name (upper) (9-letters)
+	 	Day	- full day name - first character is upper (9-letters)
+		day	- full day name - all characters is upper (9-letters)
+	 	DY	- abbreviated day name (3-letters) (upper)
+	 	Dy	- abbreviated day name (3-letters) - first character is upper 
+	 	Dy	- abbreviated day name (3-letters) - all character is upper 
+	 	DDD	- day of year (001-366)
+	 	DD	- day of month (01-31)
+	 	D	- day of week (1-7; SUN=1)
+	 	WW	- week number of year
+	 	CC	- century (2-digits)
+		Q	- quarter
+		RM	- roman numeral month (I=JAN; I-XII)
+		W	- week of month 
+		J	- julian day (days since January 1, 4712 BC)
+
+
+	AC / BC:
+	-------
+
+		TO-FROM CHAR routines support BC and AC postfix for years.
+		You can combine BC and AC with TH.
+
+	OTHER:
+        -----
+		'\'	- must be use as double \\
+
+			'\\HH\\MI\\SS'	 -->	11\45\56 
+
+		'"'	- string berween a quotation marks is skipen and not
+			is parsed. If you wand write '"' to output you must
+			use \\"
+	
+			'"Month: "Month'   -->	Month: November	
+			'\\"YYYY Month\\"' -->  "1999 November "
+
+		text	- the PostgreSQL TO-FROM CHAR support text without '"',
+			but " text " is fastly and you have guarantee,
+			that this text not will interprete as keyword.  
+
+	WARNING:
+	-------
+
+		You DON'T OMIT differention between fill mode (FM prefix)
+		and standard input in FROM_CHAR (TO_DATE), because this
+		routines can't scan your input string and conver it to
+		Datetime. See:	
+
+		WRONG:		FROM_CHAR('August 1999', 'Month YYYY');
+
+		RIGHT:		FROM_CHAR('August    1999', 'Month YYYY');
+			or	FROM_CHAR('August 1999', 'FMMonth YYYY');	
+
+		(! Month is 9-letters string if you not set fill-mode !)  
+
+
+---------------------------
+TODO / Now is not supported:
+---------------------------
+
+	- spelled-out SP suffix	( 22 --> Twenty-two )
+	- AM/PM
+
+	- not supported number to character converting
+	
+		TO_CHAR(number, 'format')
+		
+
+
+-------------------------------------------------------------------------------
+- secondary products :-) ------------------------------------------------------
+-------------------------------------------------------------------------------
+
+
+ORDINAL(int4, text)
+-------------------	
+
+	* Translate number to ordinal number and return this as text
+
+
+* Examples: 
+
+template1=> select ordinal(21212, 'TH');
+ordinal
+-------
+21212ND
+
+template1=> select ordinal(21212, 'th');
+ordinal
+-------
+21212nd

contrib/dateformat/to-from_char.h

+
+#ifndef TO_FROM_CHAR_H
+#define TO_FROM_CHAR_H
+
+/*------ 
+ * For postgres 
+ *------ 
+ */
+extern text	*to_char(DateTime *dt, text *format);
+extern DateTime *from_char(text *date_str, text *format);
+extern DateADT	to_date(text *date_str, text *format);
+
+extern text 	*ordinal(int4 num, text *type);
+
+extern char	*months_full[];		/* full months name 		*/
+extern char	*rm_months[];		/* roman numeral of months	*/
+
+#endif
\ No newline at end of file

contrib/dateformat/to-from_char.sql.in

+-- to-from_char.sql datetime routines --
+--
+-- Copyright (c) 1999, Karel Zak "Zakkr" <zakkr@zf.jcu.cz>
+--
+-- This file is distributed under the GNU General Public License
+-- either version 2, or (at your option) any later version.
+
+
+-- Define the new functions
+--
+
+create function to_char(datetime, text) returns text
+  as 'MODULE_PATHNAME' 
+  language 'c';
+
+create function from_char(text, text) returns datetime
+  as 'MODULE_PATHNAME' 
+  language 'c';
+
+create function to_date(text, text) returns date
+  as 'MODULE_PATHNAME' 
+  language 'c';
+ 
+create function ordinal(int, text) returns text
+  as 'MODULE_PATHNAME' 
+  language 'c';
+
+
+-- end of file
\ No newline at end of file