mirror of https://github.com/postgres/postgres
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/
REL7_0_PATCHES
Bruce Momjian
27 years ago
parent
1f747c6722
commit
1c5aec60bb
@ -0,0 +1,71 @@ |
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#-------------------------------------------------------------------------
|
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#
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# Makefile --
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#
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# Makefile for TO-FROM_CHAR module.
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#
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#-------------------------------------------------------------------------
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PGDIR = ../..
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SRCDIR = $(PGDIR)/src
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include $(SRCDIR)/Makefile.global |
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INCLUDE_OPT = -I ./ \
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-I $(SRCDIR)/ \
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-I $(SRCDIR)/include \
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-I $(SRCDIR)/port/$(PORTNAME)
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CFLAGS += $(INCLUDE_OPT) $(CFLAGS_SL)
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MODNAME = to-from_char
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SQLDEFS = $(MODNAME).sql
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MODULE = $(MODNAME)$(DLSUFFIX)
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MODDIR = $(LIBDIR)/modules
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SQLDIR = $(LIBDIR)/sql
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all: module sql |
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module: $(MODULE) |
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sql: $(SQLDEFS) |
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install: $(MODULE) $(SQLDEFS) $(MODDIR) $(SQLDIR) |
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cp -p $(MODULE) $(MODDIR)/
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strip $(MODDIR)/$(MODULE)
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cp -p $(SQLDEFS) $(SQLDIR)/
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install-doc: |
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if [ -d "$(DOCDIR)" ]; then \
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cp -p *.doc $(DOCDIR); \
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else \
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cp -p *.doc $(SQLDIR); \
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fi
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$(MODDIR): |
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mkdir -p $@
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$(SQLDIR): |
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mkdir -p $@
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%.sql: %.sql.in |
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sed "s|MODULE_PATHNAME|$(MODDIR)/$(MODULE)|" < $< > $@
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.SUFFIXES: $(DLSUFFIX) |
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%$(DLSUFFIX): %.c |
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$(CC) $(CFLAGS) -shared -o $@ $<
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depend dep: |
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$(CC) -MM $(INCLUDE_OPT) *.c >depend
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clean: |
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rm -f *~ $(MODULE) $(MODNAME).sql
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ifeq (depend,$(wildcard depend)) |
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include depend |
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endif |
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@ -0,0 +1,25 @@ |
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PROGRAM = rand_datetime
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OBJECTS = rand_datetime.o
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CFLAGS = -Wall -fpic -O3
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CC = gcc
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RM = rm -f
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LIBS =
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INCLUDE =
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COMPILE = $(CC) $(CPPFLAGS) $(CFLAGS) $(INCLUDE)
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LINK = $(CC) $(CFLAGS) -o $@ $(LIBS)
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all: $(PROGRAM) |
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$(PROGRAM): $(OBJECTS) |
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$(LINK) $(OBJECTS)
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.c.o: $< |
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$(COMPILE) -c $<
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clean: |
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$(RM) -f *~ $(OBJECTS) $(PROGRAM)
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@ -0,0 +1,33 @@ |
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TO/FROM CHAR tests |
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~~~~~~~~~~~~~~~~~~ |
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* rand_datetime |
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The program 'rand_datetime' output a random datetime strings |
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(with yaer range 0..9999), you can use this for datetime testing. |
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You can usage this (example) for table filling. |
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Usage: |
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./rand_datetime <randfile> <num> <prefix> <postfix> |
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Example: |
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./rand_datetime /dev/urandom 2 "INSERT INTO tab VALUES('" "'::datetime);" |
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INSERT INTO tab VALUES('Sat 27 Jul 13:08:57 19618'::datetime); |
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INSERT INTO tab VALUES('Wed 25 Aug 20:31:50 27450'::datetime); |
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* regress |
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psql < regress.sql (all answers, must be TRUE, for Posgres |
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datestyle) |
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--> TO_DATE() is simular as FROM_CHAR(), but convert full datetime |
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to date ==> needn't test (?). |
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@ -0,0 +1,71 @@ |
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#include <stdio.h> |
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#include <errno.h> |
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#include <ctype.h> |
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#include <stdlib.h> |
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char *month[] = { |
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"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec",NULL
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}; |
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char *day[] = { "Sun","Mon","Tue","Wed","Thu","Fri","Sat", NULL }; |
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int num(FILE *f, int min, int max) |
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{ |
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int x, y, one; |
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one = x = fgetc(f); |
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if (x < min) |
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x = min;
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else if (x > max) { |
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while(x > max) |
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x /= 2;
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return x; |
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} |
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do { |
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y = fgetc(f); |
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if ((x+y) > max) |
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return x; |
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x += y; |
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} while(--one > 0); |
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return x;
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} |
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int main(int argc, char **argv) |
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{ |
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FILE *f;
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int count; |
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if (argc < 5) { |
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printf("\nUsage: %s <randfile> <num> <prefix> <postfix>\n", argv[0]); |
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printf("\n(C) Karel Zak - Zakkr 1999\n\n"); |
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exit(1); |
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} |
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if ((f = fopen(argv[1], "r")) == NULL) { |
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perror(argv[1]); |
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exit(1); |
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} |
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count = atoi(argv[2]); |
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for(; count > 0; --count) { |
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fprintf(stdout, "%s%s %02d %s %02d:%02d:%02d %d%s\n", |
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argv[3], |
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day[ num(f, 0, 6) ], |
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num(f, 1, 28), |
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month[ num(f, 0, 11) ],
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num(f, 0, 23), |
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num(f, 0, 59), |
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num(f, 0, 59), |
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num(f, 0, 9999), |
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argv[4] |
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);
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}
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exit(0); |
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} |
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@ -0,0 +1,58 @@ |
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--- |
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--- Postgres DateStyle needs all tests which parsing 'now'::datetime string |
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--- |
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SET DATESTYLE TO 'Postgres'; |
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SELECT 'now'::datetime = |
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TO_CHAR('now'::datetime, 'Dy Mon DD HH24:MI:SS YYYY')::datetime |
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as "Now vs. to_char"; |
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SELECT 'now'::datetime = |
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FROM_CHAR('now'::datetime, 'Dy Mon DD HH24:MI:SS YYYY') |
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as "Now vs. from_char"; |
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SELECT FROM_CHAR('now'::datetime, 'Dy Mon DD HH24:MI:SS YYYY') = |
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TO_CHAR('now'::datetime, 'Dy Mon DD HH24:MI:SS YYYY')::datetime |
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as "From_char vs. To_char"; |
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SELECT 'now'::datetime = |
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FROM_CHAR( |
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TO_CHAR('now'::datetime, '"Time: "HH24-MI-SS" Date: "Dy DD Mon YYYY'), |
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'"Time: "HH24-MI-SS" Date: "Dy DD Mon YYYY' |
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) |
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as "High from/to char test"; |
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SELECT TO_CHAR('now'::datetime, 'SSSS')::int = |
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TO_CHAR('now'::datetime, 'HH24')::int * 3600 + |
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TO_CHAR('now'::datetime, 'MI')::int * 60 + |
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TO_CHAR('now'::datetime, 'SS')::int |
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as "SSSS test"; |
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SELECT TO_CHAR('now'::datetime, 'WW')::int = |
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(TO_CHAR('now'::datetime, 'DDD')::int - |
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TO_CHAR('now'::datetime, 'D')::int + 7) / 7 |
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as "Week test"; |
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SELECT TO_CHAR('now'::datetime, 'Q')::int = |
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TO_CHAR('now'::datetime, 'MM')::int / 3 + 1 |
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as "Quartal test"; |
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SELECT TO_CHAR('now'::datetime, 'DDD')::int = |
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(TO_CHAR('now'::datetime, 'WW')::int * 7) - |
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(7 - TO_CHAR('now'::datetime, 'D')::int) + |
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(7 - TO_CHAR(('01-Jan-'|| |
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TO_CHAR('now'::datetime,'YYYY'))::datetime,'D')::int) |
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+1 |
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as "Week and day test"; |
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File diff suppressed because it is too large
Load Diff
@ -0,0 +1,183 @@ |
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TO_CHAR(datetime, text) |
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----------------------- |
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(returns text) |
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TO_CHAR - the DateTime function for formating date and time outputs. |
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This routine is inspire with the Oracle to_char(). |
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SELECT TO_CHAR('now'::datetime, 'HH:MI:SS YYYY'); |
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------------- |
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11:57:11 1999 |
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FROM_CHAR(text, text) |
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--------------------- |
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(returns DateTime) |
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FROM_CHAR - the PostgreSQL extension routine which read non-datetime |
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string and convert it to DateTime. This func. is inspire with the |
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Oracle to_date() routine, but in Oracle this func. return date only |
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and not support all keywords (format pictures). |
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SELECT FROM_CHAR('11:57:11 1999', 'HH:MI:SS YYYY'); |
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---------------------------- |
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Fri 01 Jan 11:57:11 1999 CET |
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TO_DATE(text, text) |
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------------------- |
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(returns Date) |
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TO_DATE - the Date function which read non-datetime (non-date) string |
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and convert it to date. All for thos func. is just as from_char(). |
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This func. is inspire with the Oracle to_date() routine. |
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SELECT TO_DATE('11:57:11 1999', 'HH:MI:SS YYYY'); |
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---------- |
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01-01-1999 |
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---------------------------------- |
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String format-KeyWords and options: |
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---------------------------------- |
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* TO_CHAR (..., 'format picture') |
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* FROM_CHAR (..., 'format picture') |
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* TO_DATE (..., 'format picture') |
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(Note: In Oracle manual is format-keyword called 'format pictures'.) |
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All keywords has suffixes (prefix or postfix), example for 2 hours: |
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keyword: HH (hour) 'HH' --> '02' |
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prefix: FM (fill mode) 'FMHH' --> '2' |
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postfix: TH (ordinal number) 'HHth' --> '02nd' |
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'FMHHth' --> '2nd' |
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Suffixes: |
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-------- |
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FM - fill mode |
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02 --> FMHH --> 2 |
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January , --> FMMonth --> January, |
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TH - upper ordinal number |
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02 --> HHTH --> 02ND |
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th - lower ordinal number |
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02 --> HHth --> 02th |
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KeyWords (format pictures): |
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-------------------------- |
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HH - hour of day (01-12) |
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HH12 - -- // -- |
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HH24 - hour (00-24) |
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MI - minute (00-59) |
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SS - socond (00-59) |
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SSSS - seconds past midnight (0-86399) |
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Y,YYY - year with comma (full PgSQL datetime range) digits) |
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YYYY - year (4 and more (full PgSQL datetime range) digits) |
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YYY - last 3 digits of year |
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YY - last 2 digits of year |
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Y - last digit of year |
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MONTH - full month name (upper) (9-letters) |
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Month - full month name - first character is upper (9-letters) |
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month - full month name - all characters is upper (9-letters) |
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MON - abbreviated month name (3-letters) |
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Mon - abbreviated month name (3-letters) - first character is upper |
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mon - abbreviated month name (3-letters) - all characters is upper |
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MM - month (01-12) |
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DAY - full day name (upper) (9-letters) |
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Day - full day name - first character is upper (9-letters) |
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day - full day name - all characters is upper (9-letters) |
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DY - abbreviated day name (3-letters) (upper) |
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Dy - abbreviated day name (3-letters) - first character is upper |
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Dy - abbreviated day name (3-letters) - all character is upper |
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DDD - day of year (001-366) |
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DD - day of month (01-31) |
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D - day of week (1-7; SUN=1) |
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WW - week number of year |
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CC - century (2-digits) |
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Q - quarter |
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RM - roman numeral month (I=JAN; I-XII) |
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W - week of month |
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J - julian day (days since January 1, 4712 BC) |
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AC / BC: |
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------- |
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TO-FROM CHAR routines support BC and AC postfix for years. |
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You can combine BC and AC with TH. |
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OTHER: |
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----- |
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'\' - must be use as double \\ |
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'\\HH\\MI\\SS' --> 11\45\56 |
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'"' - string berween a quotation marks is skipen and not |
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is parsed. If you wand write '"' to output you must |
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use \\" |
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'"Month: "Month' --> Month: November |
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'\\"YYYY Month\\"' --> "1999 November " |
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text - the PostgreSQL TO-FROM CHAR support text without '"', |
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but " text " is fastly and you have guarantee, |
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that this text not will interprete as keyword. |
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WARNING: |
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------- |
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You DON'T OMIT differention between fill mode (FM prefix) |
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and standard input in FROM_CHAR (TO_DATE), because this |
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routines can't scan your input string and conver it to |
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Datetime. See: |
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|
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WRONG: FROM_CHAR('August 1999', 'Month YYYY'); |
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RIGHT: FROM_CHAR('August 1999', 'Month YYYY'); |
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or FROM_CHAR('August 1999', 'FMMonth YYYY'); |
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(! Month is 9-letters string if you not set fill-mode !) |
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--------------------------- |
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TODO / Now is not supported: |
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--------------------------- |
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- spelled-out SP suffix ( 22 --> Twenty-two ) |
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- AM/PM |
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- not supported number to character converting |
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TO_CHAR(number, 'format') |
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------------------------------------------------------------------------------- |
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- secondary products :-) ------------------------------------------------------ |
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------------------------------------------------------------------------------- |
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ORDINAL(int4, text) |
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------------------- |
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* Translate number to ordinal number and return this as text |
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* Examples: |
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|
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template1=> select ordinal(21212, 'TH'); |
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ordinal |
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------- |
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21212ND |
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template1=> select ordinal(21212, 'th'); |
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ordinal |
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------- |
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21212nd |
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@ -0,0 +1,18 @@ |
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#ifndef TO_FROM_CHAR_H |
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#define TO_FROM_CHAR_H |
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/*------
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* For postgres
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*------
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*/ |
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extern text *to_char(DateTime *dt, text *format); |
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extern DateTime *from_char(text *date_str, text *format); |
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extern DateADT to_date(text *date_str, text *format); |
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extern text *ordinal(int4 num, text *type); |
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|
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extern char *months_full[]; /* full months name */ |
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extern char *rm_months[]; /* roman numeral of months */ |
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#endif |
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@ -0,0 +1,29 @@ |
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-- to-from_char.sql datetime routines -- |
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-- |
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-- Copyright (c) 1999, Karel Zak "Zakkr" <zakkr@zf.jcu.cz> |
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-- |
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-- This file is distributed under the GNU General Public License |
||||
-- either version 2, or (at your option) any later version. |
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|
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|
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-- Define the new functions |
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-- |
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|
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create function to_char(datetime, text) returns text |
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as 'MODULE_PATHNAME' |
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language 'c'; |
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|
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create function from_char(text, text) returns datetime |
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as 'MODULE_PATHNAME' |
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language 'c'; |
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|
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create function to_date(text, text) returns date |
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as 'MODULE_PATHNAME' |
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language 'c'; |
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|
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create function ordinal(int, text) returns text |
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as 'MODULE_PATHNAME' |
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language 'c'; |
||||
|
||||
|
||||
-- end of file |
||||
Loading…
Reference in new issue