CppSQLite - C++ Wrapper for SQLite

////////////////////////////////////////////////////////////////////////////////
// CppSQLite - A very thin wrapper around the SQLite database engine
//
// Author
//		Rob Groves, rob.groves@btinternet.com
//
// -----------------------------------------------------------------------------
// V1.0		05/03/2004	-Initial Version
//
// V1.1		09/03/2004	-Added CppSQLiteException::errorCodeAsString()
//						-Renamed CppSQLiteException::errorMess() - errorMessage()
//						-2 different CppSQLiteException constructors
//						-Added CppSQLiteBinary
//						-Now call sqlite_finalize() straight after error with
//						 sqlite_step()
//
// V1.2		02/04/2004	-Utilise sqlite_busy_timeout() and sqlite_interrupt()
//						 to help with multithreaded use
//						-Revert to single CppSQLiteException constructor
//						-Removed dependency on a Microsoft specific extension
//						-Added CppSQLiteQuery::fieldType()
//						-Added code to check for null pointers
//						-Added CppSQLiteStatement for SQLite pre-compiled statements
//						-Added CppSQLiteDB::execScalar()
////////////////////////////////////////////////////////////////////////////////
#include "CppSQLite.h"
#include <cstdlib>


// Named constant for passing to CppSQLiteException when passing it a string
// that cannot be deleted.
static const bool DONT_DELETE_MSG=false;

////////////////////////////////////////////////////////////////////////////////
// Prototypes for SQLite functions not included in SQLite DLL, but copied below
// from SQLite encode.c
////////////////////////////////////////////////////////////////////////////////
int sqlite_encode_binary(const unsigned char *in, int n, unsigned char *out);
int sqlite_decode_binary(const unsigned char *in, unsigned char *out);

////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////

CppSQLiteException::CppSQLiteException(const int nErrCode,
									char* szErrMess,
									bool bDeleteMsg/*=true*/) :
									mnErrCode(nErrCode)
{
	mpszErrMess = sqlite_mprintf("%s[%d]: %s",
								errorCodeAsString(nErrCode),
								nErrCode,
								szErrMess ? szErrMess : "");

	if (bDeleteMsg && szErrMess)
	{
		sqlite_freemem(szErrMess);
	}
}

									
CppSQLiteException::CppSQLiteException(const CppSQLiteException&  e) :
									mnErrCode(e.mnErrCode)
{
	mpszErrMess = 0;
	if (e.mpszErrMess)
	{
		mpszErrMess = sqlite_mprintf("%s", e.mpszErrMess);
	}
}


const char* CppSQLiteException::errorCodeAsString(int nErrCode)
{
	switch (nErrCode)
	{
		case SQLITE_OK          : return "SQLITE_OK";
		case SQLITE_ERROR       : return "SQLITE_ERROR";
		case SQLITE_INTERNAL    : return "SQLITE_INTERNAL";
		case SQLITE_PERM        : return "SQLITE_PERM";
		case SQLITE_ABORT       : return "SQLITE_ABORT";
		case SQLITE_BUSY        : return "SQLITE_BUSY";
		case SQLITE_LOCKED      : return "SQLITE_LOCKED";
		case SQLITE_NOMEM       : return "SQLITE_NOMEM";
		case SQLITE_READONLY    : return "SQLITE_READONLY";
		case SQLITE_INTERRUPT   : return "SQLITE_INTERRUPT";
		case SQLITE_IOERR       : return "SQLITE_IOERR";
		case SQLITE_CORRUPT     : return "SQLITE_CORRUPT";
		case SQLITE_NOTFOUND    : return "SQLITE_NOTFOUND";
		case SQLITE_FULL        : return "SQLITE_FULL";
		case SQLITE_CANTOPEN    : return "SQLITE_CANTOPEN";
		case SQLITE_PROTOCOL    : return "SQLITE_PROTOCOL";
		case SQLITE_EMPTY       : return "SQLITE_EMPTY";
		case SQLITE_SCHEMA      : return "SQLITE_SCHEMA";
		case SQLITE_TOOBIG      : return "SQLITE_TOOBIG";
		case SQLITE_CONSTRAINT  : return "SQLITE_CONSTRAINT";
		case SQLITE_MISMATCH    : return "SQLITE_MISMATCH";
		case SQLITE_MISUSE      : return "SQLITE_MISUSE";
		case SQLITE_NOLFS       : return "SQLITE_NOLFS";
		case SQLITE_AUTH        : return "SQLITE_AUTH";
		case SQLITE_FORMAT      : return "SQLITE_FORMAT";
		case SQLITE_RANGE       : return "SQLITE_RANGE";
		case SQLITE_ROW         : return "SQLITE_ROW";
		case SQLITE_DONE        : return "SQLITE_DONE";
		case CPPSQLITE_ERROR    : return "CPPSQLITE_ERROR";
		default: return "UNKNOWN_ERROR";
	}
}


CppSQLiteException::~CppSQLiteException()
{
	if (mpszErrMess)
	{
		sqlite_freemem(mpszErrMess);
		mpszErrMess = 0;
	}
}


////////////////////////////////////////////////////////////////////////////////

CppSQLiteBuffer::CppSQLiteBuffer()
{
	mpBuf = 0;
}


CppSQLiteBuffer::~CppSQLiteBuffer()
{
	clear();
}


void CppSQLiteBuffer::clear()
{
	if (mpBuf)
	{
		sqlite_freemem(mpBuf);
		mpBuf = 0;
	}

}


const char* CppSQLiteBuffer::format(const char* szFormat, ...)
{
	clear();
	va_list va;
	va_start(va, szFormat);
	mpBuf = sqlite_vmprintf(szFormat, va);
	va_end(va);
	return mpBuf;
}


////////////////////////////////////////////////////////////////////////////////

CppSQLiteBinary::CppSQLiteBinary() :
						mpBuf(0),
						mnBinaryLen(0),
						mnBufferLen(0),
						mnEncodedLen(0),
						mbEncoded(false)
{
}


CppSQLiteBinary::~CppSQLiteBinary()
{
	clear();
}


void CppSQLiteBinary::setBinary(const unsigned char* pBuf, int nLen)
{
	mpBuf = allocBuffer(nLen);
	memcpy(mpBuf, pBuf, nLen);
}


void CppSQLiteBinary::setEncoded(const unsigned char* pBuf)
{
	clear();

	mnEncodedLen = strlen((const char*)pBuf);
	mnBufferLen = mnEncodedLen + 1; // Allow for NULL terminator

	mpBuf = (unsigned char*)malloc(mnBufferLen);

	if (!mpBuf)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Cannot allocate memory",
								DONT_DELETE_MSG);
	}

	memcpy(mpBuf, pBuf, mnBufferLen);
	mbEncoded = true;
}


const unsigned char* CppSQLiteBinary::getEncoded()
{
	if (!mbEncoded)
	{
		unsigned char* ptmp = (unsigned char*)malloc(mnBinaryLen);
		memcpy(ptmp, mpBuf, mnBinaryLen);
		mnEncodedLen = sqlite_encode_binary(ptmp, mnBinaryLen, mpBuf);
		free(ptmp);
		mbEncoded = true;
	}

	return mpBuf;
}


const unsigned char* CppSQLiteBinary::getBinary()
{
	if (mbEncoded)
	{
		// in/out buffers can be the same
		mnBinaryLen = sqlite_decode_binary(mpBuf, mpBuf);

		if (mnBinaryLen == -1)
		{
			throw CppSQLiteException(CPPSQLITE_ERROR,
									"Cannot decode binary",
									DONT_DELETE_MSG);
		}

		mbEncoded = false;
	}

	return mpBuf;
}


int CppSQLiteBinary::getBinaryLength()
{
	getBinary();
	return mnBinaryLen;
}


unsigned char* CppSQLiteBinary::allocBuffer(int nLen)
{
	clear();

	// Allow extra space for encoded binary as per comments in
	// SQLite encode.c See bottom of this file for implementation
	// of SQLite functions use 3 instead of 2 just to be sure ;-)
	mnBinaryLen = nLen;
	mnBufferLen = 3 + (257*nLen)/254;

	mpBuf = (unsigned char*)malloc(mnBufferLen);

	if (!mpBuf)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Cannot allocate memory",
								DONT_DELETE_MSG);
	}

	mbEncoded = false;

	return mpBuf;
}


void CppSQLiteBinary::clear()
{
	if (mpBuf)
	{
		mnBinaryLen = 0;
		mnBufferLen = 0;
		free(mpBuf);
		mpBuf = 0;
	}
}


////////////////////////////////////////////////////////////////////////////////

CppSQLiteQuery::CppSQLiteQuery()
{
	mpVM = 0;
	mbEof = true;
	mnCols = 0;
	mpaszValues = 0;
	mpaszColNames = 0;
	mbOwnVM = false;
}


CppSQLiteQuery::CppSQLiteQuery(const CppSQLiteQuery& rQuery)
{
	mpVM = rQuery.mpVM;
	// Only one object can own the VM
	const_cast<CppSQLiteQuery&>(rQuery).mpVM = 0;
	mbEof = rQuery.mbEof;
	mnCols = rQuery.mnCols;
	mpaszValues = rQuery.mpaszValues;
	mpaszColNames = rQuery.mpaszColNames;
	mbOwnVM = rQuery.mbOwnVM;
}


CppSQLiteQuery::CppSQLiteQuery(sqlite_vm* pVM,
							bool bEof,
							int nCols,
							const char** paszValues,
							const char** paszColNames,
							bool bOwnVM/*=true*/)
{
	mpVM = pVM;
	mbEof = bEof;
	mnCols = nCols;
	mpaszValues = paszValues;
	mpaszColNames = paszColNames;
	mbOwnVM = bOwnVM;
}


CppSQLiteQuery::~CppSQLiteQuery()
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
}


CppSQLiteQuery& CppSQLiteQuery::operator=(const CppSQLiteQuery& rQuery)
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
	mpVM = rQuery.mpVM;
	// Only one object can own the VM
	const_cast<CppSQLiteQuery&>(rQuery).mpVM = 0;
	mbEof = rQuery.mbEof;
	mnCols = rQuery.mnCols;
	mpaszValues = rQuery.mpaszValues;
	mpaszColNames = rQuery.mpaszColNames;
	mbOwnVM = rQuery.mbOwnVM;
	return *this;
}


int CppSQLiteQuery::numFields()
{
	checkVM();
	return mnCols;
}


const char* CppSQLiteQuery::fieldValue(int nField)
{
	checkVM();

	if (nField < 0 || nField > mnCols-1)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return mpaszValues[nField];
}


bool CppSQLiteQuery::fieldIsNull(int nField)
{
	checkVM();
	return (fieldValue(nField) == 0);
}



const char* CppSQLiteQuery::fieldName(int nCol)
{
	checkVM();

	if (nCol < 0 || nCol > mnCols-1)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return mpaszColNames[nCol];
}


const char* CppSQLiteQuery::fieldType(int nCol)
{
	checkVM();

	if (nCol < 0 || nCol > mnCols-1)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return mpaszColNames[mnCols+nCol];
}


bool CppSQLiteQuery::eof()
{
	checkVM();
	return mbEof;
}


void CppSQLiteQuery::nextRow()
{
	checkVM();

	int nRet = sqlite_step(mpVM, &mnCols, &mpaszValues, &mpaszColNames);

	if (nRet == SQLITE_DONE)
	{
		// no rows
		mbEof = true;
	}
	else if (nRet == SQLITE_ROW)
	{
		// more rows, nothing to do
	}
	else
	{
		char *szError = 0;
		nRet = sqlite_finalize(mpVM, &szError);
		mpVM = 0;
		throw CppSQLiteException(nRet, szError);
	}
}


void CppSQLiteQuery::finalize()
{
	if (mpVM && mbOwnVM)
	{
		char *szError = 0;
		int nError = sqlite_finalize(mpVM, &szError);
		mpVM = 0;

		if (nError != SQLITE_OK)
		{
			throw CppSQLiteException(nError, szError);
		}
	}
}


void CppSQLiteQuery::checkVM()
{
	if (mpVM == 0)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Null Virtual Machine pointer",
								DONT_DELETE_MSG);
	}
}


////////////////////////////////////////////////////////////////////////////////

CppSQLiteTable::CppSQLiteTable()
{
	mpaszResults = 0;
	mnRows = 0;
	mnCols = 0;
	mnCurrentRow = 0;
}


CppSQLiteTable::CppSQLiteTable(const CppSQLiteTable& rTable)
{
	mpaszResults = rTable.mpaszResults;
	// Only one object can own the results
	const_cast<CppSQLiteTable&>(rTable).mpaszResults = 0;
	mnRows = rTable.mnRows;
	mnCols = rTable.mnCols;
	mnCurrentRow = rTable.mnCurrentRow;
}


CppSQLiteTable::CppSQLiteTable(char** paszResults, int nRows, int nCols)
{
	mpaszResults = paszResults;
	mnRows = nRows;
	mnCols = nCols;
	mnCurrentRow = 0;
}


CppSQLiteTable::~CppSQLiteTable()
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
}


CppSQLiteTable& CppSQLiteTable::operator=(const CppSQLiteTable& rTable)
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
	mpaszResults = rTable.mpaszResults;
	// Only one object can own the results
	const_cast<CppSQLiteTable&>(rTable).mpaszResults = 0;
	mnRows = rTable.mnRows;
	mnCols = rTable.mnCols;
	mnCurrentRow = rTable.mnCurrentRow;
	return *this;
}


void CppSQLiteTable::finalize()
{
	if (mpaszResults)
	{
		sqlite_free_table(mpaszResults);
		mpaszResults = 0;
	}
}


int CppSQLiteTable::numFields()
{
	checkResults();
	return mnCols;
}


int CppSQLiteTable::numRows()
{
	checkResults();
	return mnRows;
}


const char* CppSQLiteTable::fieldValue(int nField)
{
	checkResults();

	if (nField < 0 || nField > mnCols-1)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	int nIndex = (mnCurrentRow*mnCols) + mnCols + nField;
	return mpaszResults[nIndex];
}


bool CppSQLiteTable::fieldIsNull(int nField)
{
	checkResults();
	return (fieldValue(nField) == 0);
}



const char* CppSQLiteTable::fieldName(int nCol)
{
	checkResults();

	if (nCol < 0 || nCol > mnCols-1)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Invalid field index requested",
								DONT_DELETE_MSG);
	}

	return mpaszResults[nCol];
}


void CppSQLiteTable::setRow(int nRow)
{
	checkResults();

	if (nRow < 0 || nRow > mnRows-1)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Invalid row index requested",
								DONT_DELETE_MSG);
	}

	mnCurrentRow = nRow;
}


void CppSQLiteTable::checkResults()
{
	if (mpaszResults == 0)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Null Results pointer",
								DONT_DELETE_MSG);
	}
}


////////////////////////////////////////////////////////////////////////////////

CppSQLiteStatement::CppSQLiteStatement()
{
	mpDB = 0;
	mpVM = 0;
}


CppSQLiteStatement::CppSQLiteStatement(const CppSQLiteStatement& rStatement)
{
	mpDB = rStatement.mpDB;
	mpVM = rStatement.mpVM;
	// Only one object can own VM
	const_cast<CppSQLiteStatement&>(rStatement).mpVM = 0;
}


CppSQLiteStatement::CppSQLiteStatement(sqlite* pDB, sqlite_vm* pVM)
{
	mpDB = pDB;
	mpVM = pVM;
}


CppSQLiteStatement::~CppSQLiteStatement()
{
	try
	{
		finalize();
	}
	catch (...)
	{
	}
}


CppSQLiteStatement& CppSQLiteStatement::operator=(const CppSQLiteStatement& rStatement)
{
	mpDB = rStatement.mpDB;
	mpVM = rStatement.mpVM;
	// Only one object can own VM
	const_cast<CppSQLiteStatement&>(rStatement).mpVM = 0;
	return *this;
}


int CppSQLiteStatement::execDML()
{
	checkDB();
	checkVM();

	int nCols(0);
	char* szError=0;
	const char** paszValues=0;
	const char** paszColNames=0;

	int nRet = sqlite_step(mpVM, &nCols, &paszValues, &paszColNames);

	if (nRet == SQLITE_DONE)
	{
		int nRowsChanged = sqlite_last_statement_changes(mpDB);

		nRet = sqlite_reset(mpVM, &szError);

		if (nRet != SQLITE_OK)
		{
			throw CppSQLiteException(nRet, szError);
		}

		return nRowsChanged;
	}
	else
	{
		nRet = sqlite_reset(mpVM, &szError);
		throw CppSQLiteException(nRet, szError);
	}
}


CppSQLiteQuery CppSQLiteStatement::execQuery()
{
	checkDB();
	checkVM();

	int nCols(0);
	const char** paszValues=0;
	const char** paszColNames=0;

	int nRet = sqlite_step(mpVM, &nCols, &paszValues, &paszColNames);

	if (nRet == SQLITE_DONE)
	{
		// no rows
		return CppSQLiteQuery(mpVM, true/*eof*/, nCols, paszValues, paszColNames, false);
	}
	else if (nRet == SQLITE_ROW)
	{
		// at least 1 row
		return CppSQLiteQuery(mpVM, false/*eof*/, nCols, paszValues, paszColNames, false);
	}
	else
	{
		char* szError=0;
		nRet = sqlite_finalize(mpVM, &szError);
		throw CppSQLiteException(nRet, szError);
	}
}


void CppSQLiteStatement::bind(int nParam, const char* szValue)
{
	checkVM();
	sqlite_bind(mpVM, nParam, szValue, -1, 1);
}


void CppSQLiteStatement::bind(int nParam, const int nValue)
{
	char buf[16];
	sprintf(buf, "%d", nValue);
	bind(nParam, buf);
}


void CppSQLiteStatement::bind(int nParam, const double dValue)
{
	char buf[16];
	sprintf(buf, "%f", dValue);
	bind(nParam, buf);
}


void CppSQLiteStatement::bindNull(int nParam)
{
	checkVM();
	sqlite_bind(mpVM, nParam, 0, -1, 1);
}


void CppSQLiteStatement::reset()
{
	if (mpVM)
	{
		char *szError = 0;
		int nError = sqlite_reset(mpVM, &szError);

		if (nError != SQLITE_OK)
		{
			throw CppSQLiteException(nError, szError);
		}
	}
}


void CppSQLiteStatement::finalize()
{
	if (mpVM)
	{
		char *szError = 0;
		int nError = sqlite_finalize(mpVM, &szError);
		mpVM = 0;

		if (nError != SQLITE_OK)
		{
			throw CppSQLiteException(nError, szError);
		}
	}
}


void CppSQLiteStatement::checkDB()
{
	if (mpDB == 0)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Database not open",
								DONT_DELETE_MSG);
	}
}


void CppSQLiteStatement::checkVM()
{
	if (mpVM == 0)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Null Virtual Machine pointer",
								DONT_DELETE_MSG);
	}
}


////////////////////////////////////////////////////////////////////////////////

CppSQLiteDB::CppSQLiteDB()
{
	mpDB = 0;
	mnBusyTimeoutMs = 60000; // 60 seconds
}


CppSQLiteDB::CppSQLiteDB(const CppSQLiteDB& db)
{
	mpDB = db.mpDB;
	mnBusyTimeoutMs = 60000; // 60 seconds
}


CppSQLiteDB::~CppSQLiteDB()
{
	close();
}


CppSQLiteDB& CppSQLiteDB::operator=(const CppSQLiteDB& db)
{
	mpDB = db.mpDB;
	mnBusyTimeoutMs = 60000; // 60 seconds
	return *this;
}


void CppSQLiteDB::open(const char* szFile)
{
	char *szError = 0;
	mpDB = sqlite_open(szFile, 0, &szError);

	if (!mpDB)
	{
		throw CppSQLiteException(SQLITE_CANTOPEN, szError);
	}

	setBusyTimeout(mnBusyTimeoutMs);
}


void CppSQLiteDB::close()
{
	if (mpDB)
	{
		sqlite_close(mpDB);
		mpDB = 0;
	}
}


CppSQLiteStatement CppSQLiteDB::compileStatement(const char* szSQL)
{
	checkDB();

	sqlite_vm* pVM = compile(szSQL);
	return CppSQLiteStatement(mpDB, pVM);
}


int CppSQLiteDB::execDML(const char* szSQL)
{
	checkDB();

	sqlite_vm* pVM = compile(szSQL);

	int nCols(0);
	char* szError=0;
	const char** paszValues=0;
	const char** paszColNames=0;

	int nRet = sqlite_step(pVM, &nCols, &paszValues, &paszColNames);

	if (nRet == SQLITE_DONE)
	{
		int nRowsChanged = sqlite_changes(mpDB);

		nRet = sqlite_finalize(pVM, &szError);

		if (nRet != SQLITE_OK)
		{
			throw CppSQLiteException(nRet, szError);
		}

		return nRowsChanged;
	}
	else
	{
		nRet = sqlite_finalize(pVM, &szError);
		throw CppSQLiteException(nRet, szError);
	}
}


CppSQLiteQuery CppSQLiteDB::execQuery(const char* szSQL)
{
	checkDB();

	sqlite_vm* pVM = compile(szSQL);

	int nCols(0);
	const char** paszValues=0;
	const char** paszColNames=0;

	int nRet = sqlite_step(pVM, &nCols, &paszValues, &paszColNames);

	if (nRet == SQLITE_DONE)
	{
		// no rows
		return CppSQLiteQuery(pVM, true/*eof*/, nCols, paszValues, paszColNames);
	}
	else if (nRet == SQLITE_ROW)
	{
		// at least 1 row
		return CppSQLiteQuery(pVM, false/*eof*/, nCols, paszValues, paszColNames);
	}
	else
	{
		char* szError=0;
		nRet = sqlite_finalize(pVM, &szError);
		throw CppSQLiteException(nRet, szError);
	}
}


int CppSQLiteDB::execScalar(const char* szSQL)
{
	CppSQLiteQuery q = execQuery(szSQL);

	if (q.eof() || q.numFields() < 1)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Invalid scalar query",
								DONT_DELETE_MSG);
	}

	return atoi(q.fieldValue(0));
}


CppSQLiteTable CppSQLiteDB::getTable(const char* szSQL)
{
	checkDB();

	char* szError=0;
	char** paszResults=0;
	int nRet;
	int nRows(0);
	int nCols(0);

	nRet = sqlite_get_table(mpDB, szSQL, &paszResults, &nRows, &nCols, &szError);

	if (nRet == SQLITE_OK)
	{
		return CppSQLiteTable(paszResults, nRows, nCols);
	}
	else
	{
		throw CppSQLiteException(nRet, szError);
	}
}


int CppSQLiteDB::lastRowId()
{
	return sqlite_last_insert_rowid(mpDB);
}


void CppSQLiteDB::setBusyTimeout(int nMillisecs)
{
	mnBusyTimeoutMs = nMillisecs;
	sqlite_busy_timeout(mpDB, mnBusyTimeoutMs);
}


void CppSQLiteDB::checkDB()
{
	if (!mpDB)
	{
		throw CppSQLiteException(CPPSQLITE_ERROR,
								"Database not open",
								DONT_DELETE_MSG);
	}
}


sqlite_vm* CppSQLiteDB::compile(const char* szSQL)
{
	checkDB();

	char* szError=0;
	const char* szTail=0;
	sqlite_vm* pVM;

	int nRet = sqlite_compile(mpDB, szSQL, &szTail, &pVM, &szError);

	if (nRet != SQLITE_OK)
	{
		throw CppSQLiteException(nRet, szError);
	}

	return pVM;
}


////////////////////////////////////////////////////////////////////////////////
// SQLite encode.c reproduced here, containing implementation notes and source
// for sqlite_encode_binary() and sqlite_decode_binary() 
////////////////////////////////////////////////////////////////////////////////

/*
** 2002 April 25
**
** 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 contains helper routines used to translate binary data into
** a null-terminated string (suitable for use in SQLite) and back again.
** These are convenience routines for use by people who want to store binary
** data in an SQLite database.  The code in this file is not used by any other
** part of the SQLite library.
**
** $Id: encode.c,v 1.10 2004/01/14 21:59:23 drh Exp $
*/

/*
** How This Encoder Works
**
** The output is allowed to contain any character except 0x27 (') and
** 0x00.  This is accomplished by using an escape character to encode
** 0x27 and 0x00 as a two-byte sequence.  The escape character is always
** 0x01.  An 0x00 is encoded as the two byte sequence 0x01 0x01.  The
** 0x27 character is encoded as the two byte sequence 0x01 0x03.  Finally,
** the escape character itself is encoded as the two-character sequence
** 0x01 0x02.
**
** To summarize, the encoder works by using an escape sequences as follows:
**
**       0x00  ->  0x01 0x01
**       0x01  ->  0x01 0x02
**       0x27  ->  0x01 0x03
**
** If that were all the encoder did, it would work, but in certain cases
** it could double the size of the encoded string.  For example, to
** encode a string of 100 0x27 characters would require 100 instances of
** the 0x01 0x03 escape sequence resulting in a 200-character output.
** We would prefer to keep the size of the encoded string smaller than
** this.
**
** To minimize the encoding size, we first add a fixed offset value to each 
** byte in the sequence.  The addition is modulo 256.  (That is to say, if
** the sum of the original character value and the offset exceeds 256, then
** the higher order bits are truncated.)  The offset is chosen to minimize
** the number of characters in the string that need to be escaped.  For
** example, in the case above where the string was composed of 100 0x27
** characters, the offset might be 0x01.  Each of the 0x27 characters would
** then be converted into an 0x28 character which would not need to be
** escaped at all and so the 100 character input string would be converted
** into just 100 characters of output.  Actually 101 characters of output - 
** we have to record the offset used as the first byte in the sequence so
** that the string can be decoded.  Since the offset value is stored as
** part of the output string and the output string is not allowed to contain
** characters 0x00 or 0x27, the offset cannot be 0x00 or 0x27.
**
** Here, then, are the encoding steps:
**
**     (1)   Choose an offset value and make it the first character of
**           output.
**
**     (2)   Copy each input character into the output buffer, one by
**           one, adding the offset value as you copy.
**
**     (3)   If the value of an input character plus offset is 0x00, replace
**           that one character by the two-character sequence 0x01 0x01.
**           If the sum is 0x01, replace it with 0x01 0x02.  If the sum
**           is 0x27, replace it with 0x01 0x03.
**
**     (4)   Put a 0x00 terminator at the end of the output.
**
** Decoding is obvious:
**
**     (5)   Copy encoded characters except the first into the decode 
**           buffer.  Set the first encoded character aside for use as
**           the offset in step 7 below.
**
**     (6)   Convert each 0x01 0x01 sequence into a single character 0x00.
**           Convert 0x01 0x02 into 0x01.  Convert 0x01 0x03 into 0x27.
**
**     (7)   Subtract the offset value that was the first character of
**           the encoded buffer from all characters in the output buffer.
**
** The only tricky part is step (1) - how to compute an offset value to
** minimize the size of the output buffer.  This is accomplished by testing
** all offset values and picking the one that results in the fewest number
** of escapes.  To do that, we first scan the entire input and count the
** number of occurances of each character value in the input.  Suppose
** the number of 0x00 characters is N(0), the number of occurances of 0x01
** is N(1), and so forth up to the number of occurances of 0xff is N(255).
** An offset of 0 is not allowed so we don't have to test it.  The number
** of escapes required for an offset of 1 is N(1)+N(2)+N(40).  The number
** of escapes required for an offset of 2 is N(2)+N(3)+N(41).  And so forth.
** In this way we find the offset that gives the minimum number of escapes,
** and thus minimizes the length of the output string.
*/

/*
** Encode a binary buffer "in" of size n bytes so that it contains
** no instances of characters '\'' or '\000'.  The output is 
** null-terminated and can be used as a string value in an INSERT
** or UPDATE statement.  Use sqlite_decode_binary() to convert the
** string back into its original binary.
**
** The result is written into a preallocated output buffer "out".
** "out" must be able to hold at least 2 +(257*n)/254 bytes.
** In other words, the output will be expanded by as much as 3
** bytes for every 254 bytes of input plus 2 bytes of fixed overhead.
** (This is approximately 2 + 1.0118*n or about a 1.2% size increase.)
**
** The return value is the number of characters in the encoded
** string, excluding the "\000" terminator.
*/
int sqlite_encode_binary(const unsigned char *in, int n, unsigned char *out){
  int i, j, e, m;
  int cnt[256];
  if( n<=0 ){
    out[0] = 'x';
    out[1] = 0;
    return 1;
  }
  memset(cnt, 0, sizeof(cnt));
  for(i=n-1; i>=0; i--){ cnt[in[i]]++; }
  m = n;
  for(i=1; i<256; i++){
    int sum;
    if( i=='\'' ) continue;
    sum = cnt[i] + cnt[(i+1)&0xff] + cnt[(i+'\'')&0xff];
    if( sum<m ){
      m = sum;
      e = i;
      if( m==0 ) break;
    }
  }
  out[0] = e;
  j = 1;
  for(i=0; i<n; i++){
    int c = (in[i] - e)&0xff;
    if( c==0 ){
      out[j++] = 1;
      out[j++] = 1;
    }else if( c==1 ){
      out[j++] = 1;
      out[j++] = 2;
    }else if( c=='\'' ){
      out[j++] = 1;
      out[j++] = 3;
    }else{
      out[j++] = c;
    }
  }
  out[j] = 0;
  return j;
}

/*
** Decode the string "in" into binary data and write it into "out".
** This routine reverses the encoding created by sqlite_encode_binary().
** The output will always be a few bytes less than the input.  The number
** of bytes of output is returned.  If the input is not a well-formed
** encoding, -1 is returned.
**
** The "in" and "out" parameters may point to the same buffer in order
** to decode a string in place.
*/
int sqlite_decode_binary(const unsigned char *in, unsigned char *out){
  int i, c, e;
  e = *(in++);
  i = 0;
  while( (c = *(in++))!=0 ){
    if( c==1 ){
      c = *(in++);
      if( c==1 ){
        c = 0;
      }else if( c==2 ){
        c = 1;
      }else if( c==3 ){
        c = '\'';
      }else{
        return -1;
      }
    }
    out[i++] = (c + e)&0xff;
  }
  return i;
}