SQLite

** This file contains the C functions that implement date and time
** functions for SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: date.c,v 1.11 2004/02/21 03:28:18 drh Exp $
**
** NOTES:
**
** SQLite processes all times and dates as Julian Day numbers.  The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system.

**     YYYY-MM-DD
**
** Write the result into the DateTime structure and return 0
** on success and 1 if the input string is not a well-formed
** date.
*/
static int parseYyyyMmDd(const char *zDate, DateTime *p){
  int Y, M, D, neg;

  if( zDate[0]=='-' ){
    zDate++;
    neg = 1;
  }else{
    neg = 0;
  }
  Y = getDigits(zDate, 4);
  if( Y<0 || zDate[4]!='-' ) return 1;
  zDate += 5;
  M = getDigits(zDate, 2);
  if( M<=0 || M>12 || zDate[2]!='-' ) return 1;
  zDate += 3;
  D = getDigits(zDate, 2);
  if( D<=0 || D>31 ) return 1;
  zDate += 2;
  while( isspace(*zDate) ){ zDate++; }
  if( isdigit(*zDate) ){
    if( parseHhMmSs(zDate, p) ) return 1;
  }else if( *zDate==0 ){
    p->validHMS = 0;
  }else{
    return 1;
  }
  p->validJD = 0;
  p->validYMD = 1;
  p->Y = neg ? -Y : Y;
  p->M = M;
  p->D = D;
  if( p->validTZ ){
    computeJD(p);
  }
  return 0;
}

** In the first form, the +/-HH:MM is always optional.  The fractional
** seconds extension (the ".FFF") is optional.  The seconds portion
** (":SS.FFF") is option.  The year and date can be omitted as long
** as there is a time string.  The time string can be omitted as long
** as there is a year and date.
*/
static int parseDateOrTime(const char *zDate, DateTime *p){

  memset(p, 0, sizeof(*p));


  if( parseYyyyMmDd(zDate,p)==0 ){

    return 0;
  }else if( parseHhMmSs(zDate, p)==0 ){
    return 0;
  }else if( sqliteStrICmp(zDate,"now")==0){
    double r;
    if( sqliteOsCurrentTime(&r)==0 ){
      p->rJD = r;
      p->validJD = 1;
      return 0;
    }
    return 1;

# 2003 October 31
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing date and time functions.
#
# $Id: date.test,v 1.6 2004/02/21 03:28:18 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

proc datetest {tnum expr result} {
  do_test date-$tnum [subst {
    execsql "SELECT coalesce($expr,'NULL')"

datetest 8.14 {datetime('now','-13 month')} {2002-09-22 12:34:00}
datetest 8.15 {datetime('now','1.5 months')} {2003-12-07 12:34:00}
datetest 8.16 {datetime('now','-5 years')} {1998-10-22 12:34:00}
datetest 8.17 {datetime('now','+10.5 minutes')} {2003-10-22 12:44:30}
datetest 8.18 {datetime('now','-1.25 hours')} {2003-10-22 11:19:00}
datetest 8.19 {datetime('now','11.25 seconds')} {2003-10-22 12:34:11}
set sqlite_current_time 0

# Negative years work.  Example:  '-4713-11-26' is JD 1.5.
#
datetest 9.1 {julianday('-4713-11-24 12:00:00')} {0}
datetest 9.2 {julianday(datetime(5))} {5}
datetest 9.3 {julianday(datetime(10))} {10}
datetest 9.4 {julianday(datetime(100))} {100}
datetest 9.5 {julianday(datetime(1000))} {1000}
datetest 9.6 {julianday(datetime(10000))} {10000}
datetest 9.7 {julianday(datetime(100000))} {100000}


finish_test