set rcsid {$Id: capi3.tcl,v 1.4 2004/06/17 19:04:17 drh Exp $}
source common.tcl
header {C/C++ Interface For SQLite Version 3}
puts {
<h2>C/C++ Interface For SQLite Version 3</h2>

<h3>1.0 Overview</h3>

<p>
SQLite version 3.0 will be a new version of SQLite, derived from
the SQLite 2.8.13 code base, but with an incompatible file format
and API.
SQLite version 3.0 is intended to answer the increasing demand
for the following features:
</p>

<ul>
<li>Support for UTF-16.</li>
<li>User-definable text collating sequences.</li>
<li>The ability to store BLOBs in indexed columns.</li>
</ul>

<p>
It became necessary to move to version 3.0
to implement these features because each
requires incompatible changes to the database file format.  Other
incompatible changes, such as a cleanup of the API, were introduced
at the same time under the theory that it is best to get your
incompatible changes out of the way all at once.
</p>

<p>
The API for version 3.0 is similar to the version 2.X API,
but with some important changes.  Most noticeably, the "<tt>sqlite_</tt>"
prefix that occurs on the beginning of all API functions and data
structures will be changed to "<tt>sqlite3_</tt>".  
This will avoid confusion between the two APIs and allow
linking against both SQLite 2.X and SQLite 3.0 at the same time,
if desired.
</p>

<p>
There is no agreement on what the C datatype for a UTF-16
string should be.  Therefore, SQLite uses a generic type of void*
to refer to UTF-16 strings.
Client software can cast the void*
to whatever datatype is appropriate for their system.
</p>

<h3>2.0 C/C++ Interface</h3>

<p>
The API for SQLite 3.0 three includes 83 separate functions in addition
................................................................................

<p>
The sqlite3_open() routine returns an integer error code rather than
a pointer to the sqlite3 structure as the version 2 interface did.
The difference between sqlite3_open()
and sqlite3_open16() is that sqlite3_open16() takes UTF-16 (in host native
byte order) for the name of the database file.  If a new database file
needs to be created, then sqlite3_open16() will set the internal text
representation to UTF-16 whereas sqlite3_open() will set the text
representation to UTF-8.
</p>

<p>
The opening and/or creating of the database file is deferred until the
file is actually needed.  This allows options and parameters, such
as the native text representation and default page size, to be
set using PRAGMA statements.
</p>

<p>
The sqlite3_errcode() routine will return the result code for the most
recent major API call.  sqlite3_errmsg() will return an English-language
text error message for the most recent error.  The error message will
be represented in UTF-8 and will be ephemeral - it could disappear on
the next call to any SQLite API function.  sqlite3_errmsg16() works like
sqlite3_errmsg() except that it returns the error message represented
as UTF-16 in host native byte order.
</p>

<p>
The error codes for SQLite version 3 are unchanged from version2.
................................................................................
   int sqlite3_prepare16(sqlite3*, const void*, int, sqlite3_stmt**, const void**);
   int sqlite3_finalize(sqlite3_stmt*);
   int sqlite3_reset(sqlite3_stmt*);
</pre></blockquote>

<p>
The sqlite3_prepare interface compiles a single SQL statement into byte code
for later execution.
This interface is now the preferred way of accessing the database.
</p>

<p>
The SQL statement is a UTF-8 string for sqlite3_prepare().
The sqlite3_prepare16() works the same way except
that it expects a UTF-16 string as SQL input.
Only the first SQL statement in the input string is compiled.

set rcsid {$Id: capi3.tcl,v 1.5 2004/06/18 11:34:09 danielk1977 Exp $}
source common.tcl
header {C/C++ Interface For SQLite Version 3}
puts {
<h2>C/C++ Interface For SQLite Version 3</h2>

<h3>1.0 Overview</h3>

<p>
SQLite version 3.0 is a new version of SQLite, derived from
the SQLite 2.8.13 code base, but with an incompatible file format
and API.

SQLite version 3.0 was created to answer demand for the following features:
</p>

<ul>
<li>Support for UTF-16.</li>
<li>User-definable text collating sequences.</li>
<li>The ability to store BLOBs in indexed columns.</li>
</ul>

<p>

It was necessary to move to version 3.0 to implement these features because
each requires incompatible changes to the database file format.  Other
incompatible changes, such as a cleanup of the API, were introduced at the
same time under the theory that it is best to get your incompatible changes
out of the way all at once.  
</p>

<p>
The API for version 3.0 is similar to the version 2.X API,
but with some important changes.  Most noticeably, the "<tt>sqlite_</tt>"
prefix that occurs on the beginning of all API functions and data
structures are changed to "<tt>sqlite3_</tt>".  
This avoids confusion between the two APIs and allows linking against both
SQLite 2.X and SQLite 3.0 at the same time.

</p>

<p>
There is no agreement on what the C datatype for a UTF-16
string should be.  Therefore, SQLite uses a generic type of void*

to refer to UTF-16 strings.  Client software can cast the void* 
to whatever datatype is appropriate for their system.
</p>

<h3>2.0 C/C++ Interface</h3>

<p>
The API for SQLite 3.0 three includes 83 separate functions in addition
................................................................................

<p>
The sqlite3_open() routine returns an integer error code rather than
a pointer to the sqlite3 structure as the version 2 interface did.
The difference between sqlite3_open()
and sqlite3_open16() is that sqlite3_open16() takes UTF-16 (in host native
byte order) for the name of the database file.  If a new database file
needs to be created, then sqlite3_open16() sets the internal text
representation to UTF-16 whereas sqlite3_open() sets the text
representation to UTF-8.
</p>

<p>
The opening and/or creating of the database file is deferred until the
file is actually needed.  This allows options and parameters, such
as the native text representation and default page size, to be
set using PRAGMA statements.
</p>

<p>
The sqlite3_errcode() routine returns a result code for the most
recent major API call.  sqlite3_errmsg() returns an English-language
text error message for the most recent error.  The error message is
represented in UTF-8 and will be ephemeral - it could disappear on
the next call to any SQLite API function.  sqlite3_errmsg16() works like
sqlite3_errmsg() except that it returns the error message represented
as UTF-16 in host native byte order.
</p>

<p>
The error codes for SQLite version 3 are unchanged from version2.
................................................................................
   int sqlite3_prepare16(sqlite3*, const void*, int, sqlite3_stmt**, const void**);
   int sqlite3_finalize(sqlite3_stmt*);
   int sqlite3_reset(sqlite3_stmt*);
</pre></blockquote>

<p>
The sqlite3_prepare interface compiles a single SQL statement into byte code
for later execution.  This interface is now the preferred way of accessing
the database.
</p>

<p>
The SQL statement is a UTF-8 string for sqlite3_prepare().
The sqlite3_prepare16() works the same way except
that it expects a UTF-16 string as SQL input.
Only the first SQL statement in the input string is compiled.