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 1.7 2004/01/07 03:29:16 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.

      }
      break;
    }
    case 'w': {
      /*
      **    weekday N
      **
      ** Move the date to the same time on the next occurrance of
      ** weekday N where 0==Sunday, 1==Monday, and so forth.  If the
      ** date is already on the appropriate weekday, this is a no-op.

      */
      if( strncmp(z, "weekday ", 8)==0 && getValue(&z[8],&r)>0
                 && (n=r)==r && n>=0 && r<7 ){
        int Z;
        computeYMD(p);
        computeHMS(p);
        p->validTZ = 0;
        p->validJD = 0;
        computeJD(p);
        Z = p->rJD + 1.5;
        Z %= 7;
        if( Z>n ) Z -= 7;
        p->rJD += n - Z;

        p->rJD += r/(24.0*60.0);
      }else if( n==6 && strcmp(z,"second")==0 ){
        computeJD(p);
        p->rJD += r/(24.0*60.0*60.0);
      }else if( n==5 && strcmp(z,"month")==0 ){
        int x, y;
        computeYMD(p);
        computeHMS(p);
        p->M += r;
        x = p->M>0 ? (p->M-1)/12 : (p->M-12)/12;
        p->Y += x;
        p->M -= x*12;
        p->validJD = 0;
        computeJD(p);
        y = r;
        if( y!=r ){
          p->rJD += (r - y)*30.0;
        }
      }else if( n==4 && strcmp(z,"year")==0 ){
        computeYMD(p);
        computeHMS(p);
        p->Y += r;
        p->validJD = 0;
        computeJD(p);
      }else{
        rc = 1;
      }
      p->validYMD = 0;

          }
          break;
        }
        case 'J':  sprintf(&z[j],"%.16g",x.rJD); j+=strlen(&z[j]); break;
        case 'm':  sprintf(&z[j],"%02d",x.M); j+=2; break;
        case 'M':  sprintf(&z[j],"%02d",x.m); j+=2; break;
        case 's': {
          sprintf(&z[j],"%d",(int)((x.rJD-2440587.5)*86400.0 + 0.5));
          j += strlen(&z[j]);
          break;
        }
        case 'S':  sprintf(&z[j],"%02d",(int)(x.s+0.5)); j+=2; break;
        case 'w':  z[j++] = (((int)(x.rJD+1.5)) % 7) + '0'; break;
        case 'Y':  sprintf(&z[j],"%04d",x.Y); j+=strlen(&z[j]); break;
        case '%':  z[j++] = '%'; break;
      }
    }
  }
  z[j] = 0;

# 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 1.5 2004/01/07 03:29:16 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 2.5 {date('2003-10-22','weekday 2')} 2003-10-28
datetest 2.6 {date('2003-10-22','weekday 3')} 2003-10-22
datetest 2.7 {date('2003-10-22','weekday 4')} 2003-10-23
datetest 2.8 {date('2003-10-22','weekday 5')} 2003-10-24
datetest 2.9 {date('2003-10-22','weekday 6')} 2003-10-25
datetest 2.10 {date('2003-10-22','weekday 7')} NULL
datetest 2.11 {date('2003-10-22','weekday 5.5')} NULL
datetest 2.12 {datetime('2003-10-22 12:34','weekday 0')} {2003-10-26 12:34:00}
datetest 2.13 {datetime('2003-10-22 12:34','start of month')} \
   {2003-10-01 00:00:00}
datetest 2.14 {datetime('2003-10-22 12:34','start of year')} \
   {2003-01-01 00:00:00}
datetest 2.15 {datetime('2003-10-22 12:34','start of day')} \
   {2003-10-22 00:00:00}
datetest 2.16 time('12:34:56.43') 12:34:56

      {2039-01-01 07:00:00}
  datetest 6.13 {datetime('2000-07-01 12:00:00','localtime')} \
      {2000-07-01 08:00:00}
  datetest 6.14 {datetime('1969-07-01 12:00:00','localtime')} \
      {1969-07-01 07:00:00}
  datetest 6.15 {datetime('2039-07-01 12:00:00','localtime')} \
      {2039-07-01 07:00:00}
  set sqlite_current_time \
     [db eval {SELECT strftime('%s','2000-07-01 12:34:56')}]
  datetest 6.16 {datetime('now','localtime')} {2000-07-01 08:34:56}
  set sqlite_current_time 0
}

# Date-time functions that contain NULL arguments return a NULL
# result.
#
datetest 7.1 {datetime(null)} NULL
datetest 7.2 {datetime('now',null)} NULL

datetest 7.10 {julianday(null)} NULL
datetest 7.11 {julianday('now',null)} NULL
datetest 7.12 {julianday('now','localtime',null)} NULL
datetest 7.13 {strftime(null,'now')} NULL
datetest 7.14 {strftime('%s',null)} NULL
datetest 7.15 {strftime('%s','now',null)} NULL
datetest 7.16 {strftime('%s','now','localtime',null)} NULL

# Test modifiers when the date begins as a julian day number - to
# make sure the HH:MM:SS is preserved.  Ticket #551.
#
set sqlite_current_time [db eval {SELECT strftime('%s','2003-10-22 12:34:00')}]
datetest 8.1 {datetime('now','weekday 0')} {2003-10-26 12:34:00}
datetest 8.2 {datetime('now','weekday 1')} {2003-10-27 12:34:00}
datetest 8.3 {datetime('now','weekday 2')} {2003-10-28 12:34:00}
datetest 8.4 {datetime('now','weekday 3')} {2003-10-22 12:34:00}
datetest 8.5 {datetime('now','start of month')} {2003-10-01 00:00:00}
datetest 8.6 {datetime('now','start of year')} {2003-01-01 00:00:00}
datetest 8.7 {datetime('now','start of day')} {2003-10-22 00:00:00}
datetest 8.8 {datetime('now','1 day')} {2003-10-23 12:34:00}
datetest 8.9 {datetime('now','+1 day')} {2003-10-23 12:34:00}
datetest 8.10 {datetime('now','+1.25 day')} {2003-10-23 18:34:00}
datetest 8.11 {datetime('now','-1.0 day')} {2003-10-21 12:34:00}
datetest 8.12 {datetime('now','1 month')} {2003-11-22 12:34:00}
datetest 8.13 {datetime('now','11 month')} {2004-09-22 12:34:00}
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


finish_test