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/

Author: bmomjian

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

@@ -0,0 +1,71 @@
+#-------------------------------------------------------------------------
+#
+# 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

@@ -0,0 +1,25 @@
+
+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

@@ -0,0 +1,33 @@
+
+	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

@@ -0,0 +1,71 @@
+
+#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);
+}

contrib/dateformat/test/regress.sql

@@ -0,0 +1,58 @@
+
+---
+--- 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";
+
+
+