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
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: date.c,v 1.74 2008/01/17 20:26:47 drh Exp $
**
** 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. 
**
** 1970-01-01 00:00:00 is JD 2440587.5

}

/*
** Process time function arguments.  argv[0] is a date-time stamp.
** argv[1] and following are modifiers.  Parse them all and write
** the resulting time into the DateTime structure p.  Return 0
** on success and 1 if there are any errors.



*/
static int isDate(
  sqlite3_context *context, 
  int argc, 
  sqlite3_value **argv, 
  DateTime *p
){
  int i;
  const unsigned char *z;

  if( argc==0 ) return 1;


  z = sqlite3_value_text(argv[0]);

  if( !z || parseDateOrTime(context, (char*)z, p) ){
    return 1;
  }
  for(i=1; i<argc; i++){
    if( (z = sqlite3_value_text(argv[i]))==0 || parseModifier((char*)z, p) ){
      return 1;
    }

                           (int)((x.rJD-2440587.5)*86400.0 + 0.5));
          j += strlen(&z[j]);
          break;
        }
        case 'S':  sqlite3_snprintf(3,&z[j],"%02d",(int)x.s); j+=2; break;
        case 'w':  z[j++] = (((int)(x.rJD+1.5)) % 7) + '0'; break;
        case 'Y':  sqlite3_snprintf(5,&z[j],"%04d",x.Y); j+=strlen(&z[j]);break;
        case '%':  z[j++] = '%'; break;
      }
    }
  }
  z[j] = 0;
  sqlite3_result_text(context, z, -1,
                      z==zBuf ? SQLITE_TRANSIENT : sqlite3_free);
}

/*
** current_time()
**
** This function returns the same value as time('now').
*/
static void ctimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_value *pVal = sqlite3ValueNew(0);
  if( pVal ){
    sqlite3ValueSetStr(pVal, -1, "now", SQLITE_UTF8, SQLITE_STATIC);
    timeFunc(context, 1, &pVal);
    sqlite3ValueFree(pVal);
  }
}

/*
** current_date()
**
** This function returns the same value as date('now').
*/
static void cdateFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_value *pVal = sqlite3ValueNew(0);
  if( pVal ){
    sqlite3ValueSetStr(pVal, -1, "now", SQLITE_UTF8, SQLITE_STATIC);
    dateFunc(context, 1, &pVal);
    sqlite3ValueFree(pVal);
  }
}

/*
** current_timestamp()
**
** This function returns the same value as datetime('now').
*/
static void ctimestampFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  sqlite3_value *pVal = sqlite3ValueNew(0);
  if( pVal ){
    sqlite3ValueSetStr(pVal, -1, "now", SQLITE_UTF8, SQLITE_STATIC);
    datetimeFunc(context, 1, &pVal);
    sqlite3ValueFree(pVal);
  }
}
#endif /* !defined(SQLITE_OMIT_DATETIME_FUNCS) */

#ifdef SQLITE_OMIT_DATETIME_FUNCS
/*
** If the library is compiled to omit the full-scale date and time
** handling (to get a smaller binary), the following minimal version

# 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 1.23 2007/08/31 17:42:48 danielk1977 Exp $

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

# Skip this whole file if date and time functions are omitted
# at compile-time
#

datetest 2.33 {datetime('2003-10-22 12:24','+1 abc')} NULL
datetest 2.34 {datetime('2003-10-22 12:24','+1 abcd')} NULL
datetest 2.35 {datetime('2003-10-22 12:24','+1 abcde')} NULL
datetest 2.36 {datetime('2003-10-22 12:24','+1 abcdef')} NULL
datetest 2.37 {datetime('2003-10-22 12:24','+1 abcdefg')} NULL
datetest 2.38 {datetime('2003-10-22 12:24','+1 abcdefgh')} NULL
datetest 2.39 {datetime('2003-10-22 12:24','+1 abcdefghi')} NULL

datetest 2.40 {datetime()} NULL



datetest 3.1 {strftime('%d','2003-10-31 12:34:56.432')} 31
datetest 3.2 {strftime('%f','2003-10-31 12:34:56.432')} 56.432

datetest 3.3 {strftime('%H','2003-10-31 12:34:56.432')} 12
datetest 3.4 {strftime('%j','2003-10-31 12:34:56.432')} 304
datetest 3.5 {strftime('%J','2003-10-31 12:34:56.432')} 2452944.02426426
datetest 3.6 {strftime('%m','2003-10-31 12:34:56.432')} 10
datetest 3.7 {strftime('%M','2003-10-31 12:34:56.432')} 34
datetest 3.8 {strftime('%s','2003-10-31 12:34:56.432')} 1067603696
datetest 3.9 {strftime('%S','2003-10-31 12:34:56.432')} 56