qsql_odbc.cpp

Linux下的基于X11的图形开发环境。

/****************************************************************************
**
** Implementation of ODBC driver classes
**
** Created : 001103
**
** Copyright (C) 1992-2000 Trolltech AS.  All rights reserved.
**
** This file is part of the sql module of the Qt GUI Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** Licensees holding valid Qt Enterprise Edition licenses may use this
** file in accordance with the Qt Commercial License Agreement provided
** with the Software.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** See http://www.trolltech.com/pricing.html or email [e-mail] for
**   information about Qt Commercial License Agreements.
** See http://www.trolltech.com/qpl/ for QPL licensing information.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
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**********************************************************************/

#include "qsql_odbc.h"
#include <qsqlrecord.h>

#if defined (Q_OS_WIN32)
#include <qt_windows.h>
#include <qapplication.h>
#endif
#include <qdatetime.h>
#include <private/qsqlextension_p.h>
#include <private/qinternal_p.h>
#include <stdlib.h>

// undefine this to prevent initial check of the ODBC driver 
#define ODBC_CHECK_DRIVER

static const int COLNAMESIZE = 255;
class QODBCPrivate
{
public:
    QODBCPrivate()
    : hEnv(0), hDbc(0), hStmt(0)
    {
	sql_char_type = sql_varchar_type = sql_longvarchar_type = QVariant::CString;
	unicode = FALSE;
    }

    SQLHANDLE hEnv;
    SQLHANDLE hDbc;
    SQLHANDLE hStmt;

    bool unicode;
    QVariant::Type sql_char_type;
    QVariant::Type sql_varchar_type;
    QVariant::Type sql_longvarchar_type;

    QSqlRecordInfo rInf;

    bool checkDriver() const;
    void checkUnicode();
};

class QODBCPreparedExtension : public QSqlExtension
{
public:
    QODBCPreparedExtension( QODBCResult * r )
	: result( r ) {}

    bool prepare( const QString& query )
    {
	return result->prepare( query );
    }

    bool exec()
    {
	return result->exec();
    }
    
    QODBCResult * result;
};

QString qWarnODBCHandle(int handleType, SQLHANDLE handle)
{
    SQLINTEGER nativeCode_;
    SQLSMALLINT msgLen;
    SQLRETURN r = SQL_ERROR;
    SQLTCHAR state_[SQL_SQLSTATE_SIZE+1];
    SQLTCHAR description_[SQL_MAX_MESSAGE_LENGTH];
    r = SQLGetDiagRec( handleType,
			 handle,
			 1,
			 (SQLTCHAR*)state_,
			 &nativeCode_,
			 (SQLTCHAR*)description_,
			 SQL_MAX_MESSAGE_LENGTH-1, /* in bytes, not in characters */
			 &msgLen);
    if ( r == SQL_SUCCESS || r == SQL_SUCCESS_WITH_INFO )
#ifdef UNICODE
	return QString( (const QChar*)description_, (uint)msgLen );
#else
	return QString::fromLocal8Bit( (const char*)description_ );
#endif
    return QString::null;
}

QString qODBCWarn( const QODBCPrivate* odbc)
{
    return ( qWarnODBCHandle( SQL_HANDLE_ENV, odbc->hEnv ) + " " \
	     + qWarnODBCHandle( SQL_HANDLE_DBC, odbc->hDbc ) + " " \
	     + qWarnODBCHandle( SQL_HANDLE_STMT, odbc->hStmt ) );
}

void qSqlWarning( const QString& message, const QODBCPrivate* odbc )
{
#ifdef QT_CHECK_RANGE
    qWarning( message + "\tError:" + qODBCWarn( odbc ) );
#endif
}

QSqlError qMakeError( const QString& err, int type, const QODBCPrivate* p )
{
    return QSqlError( "QODBC3: " + err, qODBCWarn(p), type );
}

QVariant::Type qDecodeODBCType( SQLSMALLINT sqltype, const QODBCPrivate* p )
{
    QVariant::Type type = QVariant::Invalid;
    switch ( sqltype ) {
    case SQL_DECIMAL:
    case SQL_NUMERIC:
    case SQL_REAL:
    case SQL_FLOAT:
    case SQL_DOUBLE:
    case SQL_BIGINT: //use high precision binding
	type = QVariant::Double;
	break;
    case SQL_SMALLINT:
    case SQL_INTEGER:
    case SQL_BIT:
    case SQL_TINYINT:
	type = QVariant::Int;
	break;
    case SQL_BINARY:
    case SQL_VARBINARY:
    case SQL_LONGVARBINARY:
	type = QVariant::ByteArray;
	break;
    case SQL_DATE:
    case SQL_TYPE_DATE:
	type = QVariant::Date;
	break;
    case SQL_TIME:
    case SQL_TYPE_TIME:
	type = QVariant::Time;
	break;
    case SQL_TIMESTAMP:
    case SQL_TYPE_TIMESTAMP:
	type = QVariant::DateTime;
	break;
    case SQL_WCHAR:
    case SQL_WVARCHAR:
    case SQL_WLONGVARCHAR:
	type = QVariant::String;
	break;
    case SQL_CHAR:
	type = p->sql_char_type;
	break;
    case SQL_VARCHAR:
	type = p->sql_varchar_type;
	break;
    case SQL_LONGVARCHAR:
	type = p->sql_longvarchar_type;
	break;
    default:
	type = QVariant::CString;
	break;
    }
    return type;
}

QString qGetStringData( SQLHANDLE hStmt, int column, int colSize, bool& isNull, bool unicode = FALSE )
{
    QString     fieldVal;
    SQLRETURN   r = SQL_ERROR;
    SQLINTEGER  lengthIndicator = 0;

    if ( colSize <= 0 ) {
	colSize = 255;
    } else if ( colSize > 65536 ) { // limit buffer size to 64 KB 
	colSize = 65536;
    } else {
	colSize++; // make sure there is room for more than the 0 termination
	if ( unicode ) {
	    colSize *= 2; // a tiny bit faster, since it saves a SQLGetData() call
	}
    }
    char* buf = new char[ colSize ];
    while ( TRUE ) {
	r = SQLGetData( hStmt,
			column+1,
			unicode ? SQL_C_WCHAR : SQL_C_CHAR,
			(SQLPOINTER)buf,
			colSize,
			&lengthIndicator );
	if ( r == SQL_SUCCESS || r == SQL_SUCCESS_WITH_INFO ) {
	    if ( lengthIndicator == SQL_NULL_DATA || lengthIndicator == SQL_NO_TOTAL ) {
		fieldVal = QString::null;
		isNull = TRUE;
		break;
	    }
	    // if SQL_SUCCESS_WITH_INFO is returned, indicating that
	    // more data can be fetched, the length indicator does NOT
	    // contain the number of bytes returned - it contains the
	    // total number of bytes that CAN be fetched
	    // colSize-1: remove 0 termination when there is more data to fetch
	    int rSize = (r == SQL_SUCCESS_WITH_INFO) ? (unicode ? colSize-2 : colSize-1) : lengthIndicator;
	    if ( unicode ) {
		fieldVal += QString( (QChar*) buf, rSize / 2 );
	    } else {
		buf[ rSize ] = 0;
		fieldVal += buf;
	    }
	    if ( lengthIndicator < colSize ) {
		// workaround for Drivermanagers that don't return SQL_NO_DATA
		break;
	    }
	} else if ( r == SQL_NO_DATA ) {
	    break;
	} else {
#ifdef QT_CHECK_RANGE
	    qWarning( "qGetStringData: Error while fetching data (%d)", r );
#endif
	    fieldVal = QString::null;
	    break;
	}
    }
    delete[] buf;
    return fieldVal;
}

QByteArray qGetBinaryData( SQLHANDLE hStmt, int column, SQLINTEGER& lengthIndicator, bool& isNull )
{
    QByteArray fieldVal;
    SQLSMALLINT colNameLen;
    SQLSMALLINT colType;
    SQLUINTEGER colSize;
    SQLSMALLINT colScale;
    SQLSMALLINT nullable;
    SQLRETURN r = SQL_ERROR;

    SQLTCHAR colName[COLNAMESIZE];
    r = SQLDescribeCol( hStmt,
			column+1,
			colName,
			COLNAMESIZE,
			&colNameLen,
			&colType,
			&colSize,
			&colScale,
			&nullable );
#ifdef QT_CHECK_RANGE
    if ( r != SQL_SUCCESS )
	qWarning( QString("qGetBinaryData: Unable to describe column %1").arg(column) );
#endif
    // SQLDescribeCol may return 0 if size cannot be determined
    if (!colSize) {
	colSize = 255;
    }
    if ( colSize > 65536 ) { // read the field in 64 KB chunks
	colSize = 65536;
    }
    char * buf = new char[ colSize ];
    while ( TRUE ) {
	r = SQLGetData( hStmt,
			column+1,
			SQL_C_BINARY,
			(SQLPOINTER) buf,
			colSize,
			&lengthIndicator );
	if ( r == SQL_SUCCESS || r == SQL_SUCCESS_WITH_INFO ) {
	    if ( lengthIndicator == SQL_NULL_DATA ) {
 		isNull = TRUE;
		break;
	    } else {
		int rSize;
		r == SQL_SUCCESS ? rSize = lengthIndicator : rSize = colSize;
		if ( lengthIndicator == SQL_NO_TOTAL ) { // size cannot be determined
		    rSize = colSize;
		}
		// NB! This is not a memleak - the mem will be deleted by QByteArray when
		// no longer ref'd
		char * tmp = (char *) malloc( rSize + fieldVal.size() );
		if ( fieldVal.size() ) {
		    memcpy( tmp, fieldVal.data(), fieldVal.size() );
		}
		memcpy( tmp + fieldVal.size(), buf, rSize );
		fieldVal = fieldVal.assign( tmp, fieldVal.size() + rSize );

		if ( r == SQL_SUCCESS ) { // the whole field was read in one chunk
		    break;
		}
	    }
	} else {
	    break;
	}
    }
    delete [] buf;
    return fieldVal;
}

int qGetIntData( SQLHANDLE hStmt, int column, bool& isNull  )
{
    SQLINTEGER intbuf;
    isNull = FALSE;
    SQLINTEGER lengthIndicator = 0;
    SQLRETURN r = SQLGetData( hStmt,
			      column+1,
			      SQL_C_SLONG,
			      (SQLPOINTER)&intbuf,
			      0,
			      &lengthIndicator );
    if ( r == SQL_SUCCESS || r == SQL_SUCCESS_WITH_INFO ) {
	if ( lengthIndicator == SQL_NULL_DATA )
	    isNull = TRUE;
    }
    return (int)intbuf;
}

// creates a QSqlFieldInfo from a valid hStmt generated
// by SQLColumns. The hStmt has to point to a valid position.
QSqlFieldInfo qMakeFieldInfo( const SQLHANDLE hStmt, const QODBCPrivate* p )
{
    bool isNull;
    QString fname = qGetStringData( hStmt, 3, -1, isNull, p->unicode );
    int type = qGetIntData( hStmt, 4, isNull ); // column type
    int required = qGetIntData( hStmt, 10, isNull ); // nullable-flag
    // required can be SQL_NO_NULLS, SQL_NULLABLE or SQL_NULLABLE_UNKNOWN
    if ( required == SQL_NO_NULLS ) {
	required = 1;
    } else if ( required == SQL_NULLABLE ) {
	required = 0;
    } else {
	required = -1;
    }
    int size = qGetIntData( hStmt, 6, isNull ); // column size
    int prec = qGetIntData( hStmt, 8, isNull ); // precision
    return QSqlFieldInfo( fname, qDecodeODBCType( type, p ), required, size, prec, QVariant(), type );
}

QSqlFieldInfo qMakeFieldInfo( const QODBCPrivate* p, int i  )
{
    SQLSMALLINT colNameLen;
    SQLSMALLINT colType;
    SQLUINTEGER colSize;
    SQLSMALLINT colScale;
    SQLSMALLINT nullable;
    SQLRETURN r = SQL_ERROR;
    SQLTCHAR colName[ COLNAMESIZE ];
    r = SQLDescribeCol( p->hStmt,
			i+1,
			colName,
			(SQLSMALLINT)COLNAMESIZE,
			&colNameLen,
			&colType,
			&colSize,
			&colScale,
			&nullable);

    if ( r != SQL_SUCCESS ) {
#ifdef QT_CHECK_RANGE
	qSqlWarning( QString("qMakeField: Unable to describe column %1").arg(i), p );
#endif
	return QSqlFieldInfo();
    }
#ifdef UNICODE
    QString qColName( (const QChar*)colName, (uint)colNameLen );
#else
    QString qColName = QString::fromLocal8Bit( (const char*)colName );
#endif
    // nullable can be SQL_NO_NULLS, SQL_NULLABLE or SQL_NULLABLE_UNKNOWN
    int required = -1;
    if ( nullable == SQL_NO_NULLS ) {
	required = 1;
    } else if ( nullable == SQL_NULLABLE ) {
	required = 0;
    }
    QVariant::Type type = qDecodeODBCType( colType, p );
    return QSqlFieldInfo( qColName,
    			  type,
    			  required,
    			  (int)colSize == 0 ? -1 : (int)colSize,
    			  (int)colScale == 0 ? -1 : (int)colScale,
    			  QVariant(),
    			  (int)colType );
}

void qSplitTableQualifier( const QString & qualifier, QString * catalog,
			   QString * schema, QString * table )
{
    if ( !catalog || !schema || !table )
	return;
    QStringList l = QStringList::split( ".", qualifier, TRUE );
    if ( l.count() > 3 )
	return; // can't possibly be a valid table qualifier
    int i = 0, n = l.count();
    if ( n == 1 ) {
	*table = qualifier;
    } else {
	for ( QStringList::Iterator it = l.begin(); it != l.end(); ++it ) {
	    if ( n == 3 ) {
		if ( i == 0 ) {
		    *catalog = *it;
		} else if ( i == 1 ) {
		    *schema = *it;
		} else if ( i == 2 ) {
		    *table = *it;
		}
	    } else if ( n == 2 ) {
		if ( i == 0 ) {
		    *schema = *it;
		} else if ( i == 1 ) {
		    *table = *it;
		}
	    }
	    i++;
	}
    }
}

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

QODBCResult::QODBCResult( const QODBCDriver * db, QODBCPrivate* p )
: QSqlResult(db)
{
    d = new QODBCPrivate();
    (*d) = (*p);
    setExtension( new QODBCPreparedExtension( this ) );
}

QODBCResult::~QODBCResult()
{
    if ( d->hStmt && driver()->isOpen() ) {
	SQLRETURN r = SQLFreeHandle( SQL_HANDLE_STMT, d->hStmt );
#ifdef QT_CHECK_RANGE
	if ( r!= SQL_SUCCESS )
		qSqlWarning( "QODBCDriver: Unable to free statement handle" + QString::number(r), d );
#endif
    }

    delete d;
}

bool QODBCResult::reset ( const QString& query )
{
    setActive( FALSE );
    setAt( QSql::BeforeFirst );
    SQLRETURN r;

    d->rInf.clear();
    // Always reallocate the statement handle - the statement attributes
    // are not reset if SQLFreeStmt() is called which causes some problems.
    if ( d->hStmt ) {
	r = SQLFreeHandle( SQL_HANDLE_STMT, d->hStmt );
	if ( r != SQL_SUCCESS ) {
#ifdef QT_CHECK_RANGE
	    qSqlWarning( "QODBCResult::reset: Unable to free statement handle", d );
#endif
	    return FALSE;
	}
    }
    r  = SQLAllocHandle( SQL_HANDLE_STMT,
			 d->hDbc,
			 &d->hStmt );
    if ( r != SQL_SUCCESS ) {
#ifdef QT_CHECK_RANGE
	qSqlWarning( "QODBCResult::reset: Unable to allocate statement handle", d );
#endif
	return FALSE;
    }

    if ( isForwardOnly() ) {
	r = SQLSetStmtAttr( d->hStmt,
	    		    SQL_ATTR_CURSOR_TYPE,
			    (SQLPOINTER)SQL_CURSOR_FORWARD_ONLY,
			    SQL_IS_UINTEGER );
    } else {
	r = SQLSetStmtAttr( d->hStmt,
			    SQL_ATTR_CURSOR_TYPE,
			    (SQLPOINTER)SQL_CURSOR_STATIC,
			    SQL_IS_UINTEGER );
    }
    if ( r != SQL_SUCCESS ) {
#ifdef QT_CHECK_RANGE
			qSqlWarning( "QODBCResult::reset: Unable to set 'SQL_CURSOR_STATIC' as statement attribute. Please check your ODBC driver configuration", d );
#endif
	return FALSE;
    }

#ifdef UNICODE
    r = SQLExecDirect( d->hStmt,
		       (SQLWCHAR*) query.unicode(),
		       (SQLINTEGER) query.length() );
#else
    QCString query8 = query.local8Bit();
    r = SQLExecDirect( d->hStmt,
                       (SQLCHAR*) query8.data(),
                       (SQLINTEGER) query8.length() );
#endif
    if ( r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO ) {
	setLastError( qMakeError( "Unable to execute statement", QSqlError::Statement, d ) );
	return FALSE;
    }
    SQLSMALLINT count;
    r = SQLNumResultCols( d->hStmt, &count );
    if ( count ) {
	setSelect( TRUE );
	for ( int i = 0; i < count; ++i ) {
	    d->rInf.append( qMakeFieldInfo( d, i ) );
	}
    } else {
	setSelect( FALSE );
    }
    setActive( TRUE );
    return TRUE;
}

bool QODBCResult::fetch(int i)
{
    if ( isForwardOnly() && i < at() )
	return FALSE;
    if ( i == at() )
	return TRUE;
    fieldCache.clear();
    nullCache.clear();
    int actualIdx = i + 1;
    if ( actualIdx <= 0 ) {
	setAt( QSql::BeforeFirst );
	return FALSE;
    }
    SQLRETURN r;
    if ( isForwardOnly() ) {
	bool ok = TRUE;
	while ( ok && i > at() )
	    ok = fetchNext();
	return ok;
    } else {
	r = SQLFetchScroll( d->hStmt,
			    SQL_FETCH_ABSOLUTE,
			    actualIdx );
    }
    if ( r != SQL_SUCCESS ){
 	return FALSE;
    }
    setAt( i );
    return TRUE;
}