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 1.41 2004/11/11 01:50:30 danielk1977 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.

/*
** If the library is compiled to omit the full-scale date and time
** handling (to get a smaller binary), the following minimal version
** of the functions current_time(), current_date() and current_timestamp()
** are included instead. This is to support column declarations that
** include "DEFAULT CURRENT_TIME" etc.
**
** This function uses the C-library functions time(), gmtime()
** and strftime(). The format string to pass to strftime() is supplied
** as the user-data for the function.
*/

static void currentTimeFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  time_t t;
  char *zFormat = (char *)sqlite3_user_data(context);

set rcsid {$Id: datatype3.tcl,v 1.9 2004/11/11 01:50:30 danielk1977 Exp $}
source common.tcl
header {Datatypes In SQLite Version 3}
puts {
<h2>Datatypes In SQLite Version 3</h2>

<h3>1. Storage Classes</h3>

	<LI><P><B>No affinity</B> mode. In this mode no conversions between
	storage classes are ever performed. Comparisons between values of
	different storage classes (except for INTEGER and REAL) are always
	false.</P>
</UL>

<a name="collation"></a>
<h3>7. User-defined Collation Sequences</h3>

<p>
By default, when SQLite compares two text values, the result of the
comparison is determined using memcmp(), regardless of the encoding of the
string. SQLite v3 provides the ability for users to supply arbitrary
comparison functions, known as user-defined collation sequences, to be used

#
# Run this Tcl script to generate the sqlite.html file.
#
set rcsid {$Id: lang.tcl,v 1.76 2004/11/11 01:50:30 danielk1977 Exp $}
source common.tcl
header {Query Language Understood by SQLite}
puts {
<h2>SQL As Understood By SQLite</h2>

<p>The SQLite library understands most of the standard SQL
language.  But it does <a href="omitted.html">omit some features</a>

datatype for that column, then one or more optional column constraints.
The datatype for the column does not restrict what data may be put
in that column.
See <a href="datatype3.html">Datatypes In SQLite Version 3</a> for
additional information.
The UNIQUE constraint causes an index to be created on the specified
columns.  This index must contain unique keys.


The COLLATE clause specifies what text <a href="datatype3.html#collation">
collating function</a> to use when comparing text entries for the column.  
The built-in BINARY collating function is used by default.
<p>
The DEFAULT constraint specifies a default value to use when doing an INSERT.
The value may be NULL, a string constant, a number, or one of the special
case-independant keywords CURRENT_TIME, CURRENT_DATE or CURRENT_TIMESTAMP.
If the value is NULL, a string constant or number, it is literally inserted
into the column whenever an INSERT statement that does not specify a value
for the column is executed. If the value is CURRENT_TIME, CURRENT_DATE or
CURRENT_TIMESTAMP, then the current UTC date and/or time is inserted into
the columns. For CURRENT_TIME, the format is HH:MM:SS. For CURRENT_DATE, 
YYYY-MM-DD. The format for CURRENT_TIMESTAMP is "YYYY-MM-DD HH:MM:SS".
</p>

<p>Specifying a PRIMARY KEY normally just creates a UNIQUE index
on the primary key.  However, if primary key is on a single column
that has datatype INTEGER, then that column is used internally
as the actual key of the B-Tree for the table.  This means that the column
may only hold unique integer values.  (Except for this one case,