/****************************************************************************
**
** Implementation of QSqlQuery class
**
** Created : 2000-11-03
**
** Copyright (C) 2000-2008 Trolltech ASA. All rights reserved.
**
** This file is part of the sql module of the Qt GUI Toolkit.
**
** This file may be used under the terms of the GNU General
** Public License versions 2.0 or 3.0 as published by the Free
** Software Foundation and appearing in the files LICENSE.GPL2
** and LICENSE.GPL3 included in the packaging of this file.
** Alternatively you may (at your option) use any later version
** of the GNU General Public License if such license has been
** publicly approved by Trolltech ASA (or its successors, if any)
** and the KDE Free Qt Foundation.
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/.
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
** or contact the sales department at sales@trolltech.com.
**
** This file may be used under the terms of the Q Public License as
** defined by Trolltech ASA and appearing in the file LICENSE.QPL
** included in the packaging of this file. Licensees holding valid Qt
** Commercial 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 WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
** herein.
**
**********************************************************************/
#include "qsqlquery.h"
#ifndef QT_NO_SQL
//#define QT_DEBUG_SQL
#include "qsqlresult.h"
#include "qsqldriver.h"
#include "qsqldatabase.h"
#include "qsql.h"
#include "qregexp.h"
#include "private/qsqlextension_p.h"
/*!
\internal
*/
QSqlResultShared::QSqlResultShared( QSqlResult* result ): sqlResult(result)
{
if ( result )
connect( result->driver(), SIGNAL(destroyed()), this, SLOT(slotResultDestroyed()) );
}
/*!
\internal
*/
QSqlResultShared::~QSqlResultShared()
{
delete sqlResult;
}
/*!
\internal
In case a plugin gets unloaded the pointer to the sqlResult gets invalid
*/
void QSqlResultShared::slotResultDestroyed()
{
delete sqlResult;
sqlResult = 0;
}
/*!
\class QSqlQuery qsqlquery.h
\brief The QSqlQuery class provides a means of executing and
manipulating SQL statements.
\ingroup database
\mainclass
\module sql
QSqlQuery encapsulates the functionality involved in creating,
navigating and retrieving data from SQL queries which are executed
on a \l QSqlDatabase. It can be used to execute DML (data
manipulation language) statements, e.g. \c SELECT, \c INSERT, \c
UPDATE and \c DELETE, and also DDL (data definition language)
statements, e.g. \c{CREATE TABLE}. It can also be used to
execute database-specific commands which are not standard SQL
(e.g. \c{SET DATESTYLE=ISO} for PostgreSQL).
Successfully executed SQL statements set the query's state to
active (isActive() returns TRUE); otherwise the query's state is
set to inactive. In either case, when executing a new SQL
statement, the query is positioned on an invalid record; an active
query must be navigated to a valid record (so that isValid()
returns TRUE) before values can be retrieved.
Navigating records is performed with the following functions:
\list
\i \c next()
\i \c prev()
\i \c first()
\i \c last()
\i \c \link QSqlQuery::seek() seek\endlink(int)
\endlist
These functions allow the programmer to move forward, backward or
arbitrarily through the records returned by the query. If you only
need to move forward through the results, e.g. using next() or
using seek() with a positive offset, you can use setForwardOnly()
and save a significant amount of memory overhead. Once an active
query is positioned on a valid record, data can be retrieved using
value(). All data is transferred from the SQL backend using
QVariants.
For example:
\code
QSqlQuery query( "SELECT name FROM customer" );
while ( query.next() ) {
QString name = query.value(0).toString();
doSomething( name );
}
\endcode
To access the data returned by a query, use the value() method.
Each field in the data returned by a SELECT statement is accessed
by passing the field's position in the statement, starting from 0.
Information about the fields can be obtained via QSqlDatabase::record().
For the sake of efficiency there are no functions to access a field
by name. (The \l QSqlCursor class provides a higher-level interface
with field access by name and automatic SQL generation.)
QSqlQuery supports prepared query execution and the binding of
parameter values to placeholders. Some databases don't support
these features, so for them Qt emulates the required
functionality. For example, the Oracle and ODBC drivers have
proper prepared query support, and Qt makes use of it; but for
databases that don't have this support, Qt implements the feature
itself, e.g. by replacing placeholders with actual values when a
query is executed. The exception is positional binding using named
placeholders, which requires that the database supports prepared
queries.
Oracle databases identify placeholders by using a colon-name
syntax, e.g \c{:name}. ODBC simply uses \c ? characters. Qt
supports both syntaxes (although you can't mix them in the same
query).
Below we present the same example using each of the four different
binding approaches.
Named binding using named placeholders
\code
QSqlQuery query;
query.prepare( "INSERT INTO atable (id, forename, surname) "
"VALUES (:id, :forename, :surname)" );
query.bindValue( ":id", 1001 );
query.bindValue( ":forename", "Bart" );
query.bindValue( ":surname", "Simpson" );
query.exec();
\endcode
Positional binding using named placeholders
\code
QSqlQuery query;
query.prepare( "INSERT INTO atable (id, forename, surname) "
"VALUES (:id, :forename, :surname)" );
query.bindValue( 0, 1001 );
query.bindValue( 1, "Bart" );
query.bindValue( 2, "Simpson" );
query.exec();
\endcode
Note: Using positional binding with named placeholders will
only work if the database supports prepared queries. This can be
checked with QSqlDriver::hasFeature() using QSqlDriver::PreparedQueries
as argument for driver feature.
Binding values using positional placeholders #1
\code
QSqlQuery query;
query.prepare( "INSERT INTO atable (id, forename, surname) "
"VALUES (?, ?, ?)" );
query.bindValue( 0, 1001 );
query.bindValue( 1, "Bart" );
query.bindValue( 2, "Simpson" );
query.exec();
\endcode
Binding values using positional placeholders #2
\code
query.prepare( "INSERT INTO atable (id, forename, surname) "
"VALUES (?, ?, ?)" );
query.addBindValue( 1001 );
query.addBindValue( "Bart" );
query.addBindValue( "Simpson" );
query.exec();
\endcode
Binding values to a stored procedure
This code calls a stored procedure called \c AsciiToInt(), passing
it a character through its in parameter, and taking its result in
the out parameter.
\code
QSqlQuery query;
query.prepare( "call AsciiToInt(?, ?)" );
query.bindValue( 0, "A" );
query.bindValue( 1, 0, QSql::Out );
query.exec();
int i = query.boundValue( 1 ).toInt(); // i is 65.
\endcode
\sa QSqlDatabase QSqlCursor QVariant
*/
/*!
Creates a QSqlQuery object which uses the QSqlResult \a r to
communicate with a database.
*/
QSqlQuery::QSqlQuery( QSqlResult * r )
{
d = new QSqlResultShared( r );
}
/*!
Destroys the object and frees any allocated resources.
*/
QSqlQuery::~QSqlQuery()
{
if (d->deref()) {
delete d;
}
}
/*!
Constructs a copy of \a other.
*/
QSqlQuery::QSqlQuery( const QSqlQuery& other )
: d(other.d)
{
d->ref();
}
/*!
Creates a QSqlQuery object using the SQL \a query and the database
\a db. If \a db is 0, (the default), the application's default
database is used. If \a query is not a null string, it will be
executed.
\sa QSqlDatabase
*/
QSqlQuery::QSqlQuery( const QString& query, QSqlDatabase* db )
{
init( query, db );
}
/*!
Creates a QSqlQuery object using the database \a db. If \a db is
0, the application's default database is used.
\sa QSqlDatabase
*/
QSqlQuery::QSqlQuery( QSqlDatabase* db )
{
init( QString::null, db );
}
/*! \internal
*/
void QSqlQuery::init( const QString& query, QSqlDatabase* db )
{
d = new QSqlResultShared( 0 );
QSqlDatabase* database = db;
if ( !database )
database = QSqlDatabase::database( QSqlDatabase::defaultConnection, FALSE );
if ( database )
*this = database->driver()->createQuery();
if ( !query.isNull() )
exec( query );
}
/*!
Assigns \a other to the query.
*/
QSqlQuery& QSqlQuery::operator=( const QSqlQuery& other )
{
other.d->ref();
deref();
d = other.d;
return *this;
}
/*!
Returns TRUE if the query is active and positioned on a valid
record and the \a field is NULL; otherwise returns FALSE. Note
that for some drivers isNull() will not return accurate
information until after an attempt is made to retrieve data.
\sa isActive() isValid() value()
*/
bool QSqlQuery::isNull( int field ) const
{
if ( !d->sqlResult )
return FALSE;
if ( d->sqlResult->isActive() && d->sqlResult->isValid() )
return d->sqlResult->isNull( field );
return FALSE;
}
/*!
Executes the SQL in \a query. Returns TRUE and sets the query
state to active if the query was successful; otherwise returns
FALSE and sets the query state to inactive. The \a query string
must use syntax appropriate for the SQL database being queried,
for example, standard SQL.
After the query is executed, the query is positioned on an \e
invalid record, and must be navigated to a valid record before
data values can be retrieved, e.g. using next().
Note that the last error for this query is reset when exec() is
called.
\sa isActive() isValid() next() prev() first() last() seek()
*/
bool QSqlQuery::exec ( const QString& query )
{
if ( !d->sqlResult )
return FALSE;
if ( d->sqlResult->extension() && driver()->hasFeature( QSqlDriver::PreparedQueries ) )
d->sqlResult->extension()->clear();
d->sqlResult->setActive( FALSE );
d->sqlResult->setLastError( QSqlError() );
d->sqlResult->setAt( QSql::BeforeFirst );
if ( !driver() ) {
#ifdef QT_CHECK_RANGE
qWarning("QSqlQuery::exec: no driver" );
#endif
return FALSE;
}
if ( d->count > 1 )
*this = driver()->createQuery();
d->sqlResult->setQuery( query.stripWhiteSpace() );
d->executedQuery = d->sqlResult->lastQuery();
if ( !driver()->isOpen() || driver()->isOpenError() ) {
#ifdef QT_CHECK_RANGE
qWarning("QSqlQuery::exec: database not open" );
#endif
return FALSE;
}
if ( query.isNull() || query.length() == 0 ) {
#ifdef QT_CHECK_RANGE
qWarning("QSqlQuery::exec: empty query" );
#endif
return FALSE;
}
#ifdef QT_DEBUG_SQL
qDebug( "\n QSqlQuery: " + query );
#endif
return d->sqlResult->reset( query );
}
/*!
Returns the value of the \a{i}-th field in the query (zero based).
The fields are numbered from left to right using the text of the
\c SELECT statement, e.g. in \c{SELECT forename, surname FROM people},
field 0 is \c forename and field 1 is \c surname. Using \c{SELECT *}
is not recommended because the order of the fields in the query is
undefined.
An invalid QVariant is returned if field \a i does not exist, if
the query is inactive, or if the query is positioned on an invalid
record.
\sa prev() next() first() last() seek() isActive() isValid()
*/
QVariant QSqlQuery::value( int i ) const
{
if ( !d->sqlResult )
return QVariant();
if ( isActive() && isValid() && ( i > QSql::BeforeFirst ) ) {
return d->sqlResult->data( i );
} else {
#ifdef QT_CHECK_RANGE
qWarning( "QSqlQuery::value: not positioned on a valid record" );
#endif
}
return QVariant();
}
/*!
Returns the current internal position of the query. The first
record is at position zero. If the position is invalid, a
QSql::Location will be returned indicating the invalid position.
\sa prev() next() first() last() seek() isActive() isValid()
*/
int QSqlQuery::at() const
{
if ( !d->sqlResult )
return QSql::BeforeFirst;
return d->sqlResult->at();
}
/*!
Returns the text of the current query being used, or QString::null
if there is no current query text.
\sa executedQuery()
*/
QString QSqlQuery::lastQuery() const
{
if ( !d->sqlResult )
return QString::null;
return d->sqlResult->lastQuery();
}
/*!
Returns the database driver associated with the query.
*/
const QSqlDriver* QSqlQuery::driver() const
{
if ( !d->sqlResult )
return 0;
return d->sqlResult->driver();
}
/*!
Returns the result associated with the query.
*/
const QSqlResult* QSqlQuery::result() const
{
return d->sqlResult;
}
/*!
Retrieves the record at position (offset) \a i, if available, and
positions the query on the retrieved record. The first record is
at position 0. Note that the query must be in an active state and
isSelect() must return TRUE before calling this function.
If \a relative is FALSE (the default), the following rules apply:
\list
\i If \a i is negative, the result is positioned before the
first record and FALSE is returned.
\i Otherwise, an attempt is made to move to the record at position
\a i. If the record at position \a i could not be retrieved, the
result is positioned after the last record and FALSE is returned. If
the record is successfully retrieved, TRUE is returned.
\endlist
If \a relative is TRUE, the following rules apply:
\list
\i If the result is currently positioned before the first
record or on the first record, and \a i is negative, there is no
change, and FALSE is returned.
\i If the result is currently located after the last record, and
\a i is positive, there is no change, and FALSE is returned.
\i If the result is currently located somewhere in the middle,
and the relative offset \a i moves the result below zero, the
result is positioned before the first record and FALSE is
returned.
\i Otherwise, an attempt is made to move to the record \a i
records ahead of the current record (or \a i records behind the
current record if \a i is negative). If the record at offset \a i
could not be retrieved, the result is positioned after the last
record if \a i >= 0, (or before the first record if \a i is
negative), and FALSE is returned. If the record is successfully
retrieved, TRUE is returned.
\endlist
\sa next() prev() first() last() at() isActive() isValid()
*/
bool QSqlQuery::seek( int i, bool relative )
{
if ( !isSelect() || !isActive() )
return FALSE;
beforeSeek();
checkDetach();
int actualIdx;
if ( !relative ) { // arbitrary seek
if ( i < 0 ) {
d->sqlResult->setAt( QSql::BeforeFirst );
afterSeek();
return FALSE;
}
actualIdx = i;
} else {
switch ( at() ) { // relative seek
case QSql::BeforeFirst:
if ( i > 0 )
actualIdx = i;
else {
afterSeek();
return FALSE;
}
break;
case QSql::AfterLast:
if ( i < 0 ) {
d->sqlResult->fetchLast();
actualIdx = at() + i;
} else {
afterSeek();
return FALSE;
}
break;
default:
if ( ( at() + i ) < 0 ) {
d->sqlResult->setAt( QSql::BeforeFirst );
afterSeek();
return FALSE;
}
actualIdx = at() + i;
break;
}
}
// let drivers optimize
if ( isForwardOnly() && actualIdx < at() ) {
#ifdef QT_CHECK_RANGE
qWarning("QSqlQuery::seek: cannot seek backwards in a forward only query" );
#endif
afterSeek();
return FALSE;
}
if ( actualIdx == ( at() + 1 ) && at() != QSql::BeforeFirst ) {
if ( !d->sqlResult->fetchNext() ) {
d->sqlResult->setAt( QSql::AfterLast );
afterSeek();
return FALSE;
}
afterSeek();
return TRUE;
}
if ( actualIdx == ( at() - 1 ) ) {
if ( !d->sqlResult->fetchPrev() ) {
d->sqlResult->setAt( QSql::BeforeFirst );
afterSeek();
return FALSE;
}
afterSeek();
return TRUE;
}
if ( !d->sqlResult->fetch( actualIdx ) ) {
d->sqlResult->setAt( QSql::AfterLast );
afterSeek();
return FALSE;
}
afterSeek();
return TRUE;
}
/*!
Retrieves the next record in the result, if available, and
positions the query on the retrieved record. Note that the result
must be in an active state and isSelect() must return TRUE before
calling this function or it will do nothing and return FALSE.
The following rules apply:
\list
\i If the result is currently located before the first
record, e.g. immediately after a query is executed, an attempt is
made to retrieve the first record.
\i If the result is currently located after the last record,
there is no change and FALSE is returned.
\i If the result is located somewhere in the middle, an attempt
is made to retrieve the next record.
\endlist
If the record could not be retrieved, the result is positioned after
the last record and FALSE is returned. If the record is successfully
retrieved, TRUE is returned.
\sa prev() first() last() seek() at() isActive() isValid()
*/
bool QSqlQuery::next()
{
if ( !isSelect() || !isActive() )
return FALSE;
beforeSeek();
checkDetach();
bool b = FALSE;
switch ( at() ) {
case QSql::BeforeFirst:
b = d->sqlResult->fetchFirst();
afterSeek();
return b;
case QSql::AfterLast:
afterSeek();
return FALSE;
default:
if ( !d->sqlResult->fetchNext() ) {
d->sqlResult->setAt( QSql::AfterLast );
afterSeek();
return FALSE;
}
afterSeek();
return TRUE;
}
}
/*!
Retrieves the previous record in the result, if available, and
positions the query on the retrieved record. Note that the result
must be in an active state and isSelect() must return TRUE before
calling this function or it will do nothing and return FALSE.
The following rules apply:
\list
\i If the result is currently located before the first record,
there is no change and FALSE is returned.
\i If the result is currently located after the last record, an
attempt is made to retrieve the last record.
\i If the result is somewhere in the middle, an attempt is made
to retrieve the previous record.
\endlist
If the record could not be retrieved, the result is positioned
before the first record and FALSE is returned. If the record is
successfully retrieved, TRUE is returned.
\sa next() first() last() seek() at() isActive() isValid()
*/
bool QSqlQuery::prev()
{
if ( !isSelect() || !isActive() )
return FALSE;
if ( isForwardOnly() ) {
#ifdef QT_CHECK_RANGE
qWarning("QSqlQuery::seek: cannot seek backwards in a forward only query" );
#endif
return FALSE;
}
beforeSeek();
checkDetach();
bool b = FALSE;
switch ( at() ) {
case QSql::BeforeFirst:
afterSeek();
return FALSE;
case QSql::AfterLast:
b = d->sqlResult->fetchLast();
afterSeek();
return b;
default:
if ( !d->sqlResult->fetchPrev() ) {
d->sqlResult->setAt( QSql::BeforeFirst );
afterSeek();
return FALSE;
}
afterSeek();
return TRUE;
}
}
/*!
Retrieves the first record in the result, if available, and
positions the query on the retrieved record. Note that the result
must be in an active state and isSelect() must return TRUE before
calling this function or it will do nothing and return FALSE.
Returns TRUE if successful. If unsuccessful the query position is
set to an invalid position and FALSE is returned.
\sa next() prev() last() seek() at() isActive() isValid()
*/
bool QSqlQuery::first()
{
if ( !isSelect() || !isActive() )
return FALSE;
if ( isForwardOnly() && at() > QSql::BeforeFirst ) {
#ifdef QT_CHECK_RANGE
qWarning("QSqlQuery::seek: cannot seek backwards in a forward only query" );
#endif
return FALSE;
}
beforeSeek();
checkDetach();
bool b = FALSE;
b = d->sqlResult->fetchFirst();
afterSeek();
return b;
}
/*!
Retrieves the last record in the result, if available, and
positions the query on the retrieved record. Note that the result
must be in an active state and isSelect() must return TRUE before
calling this function or it will do nothing and return FALSE.
Returns TRUE if successful. If unsuccessful the query position is
set to an invalid position and FALSE is returned.
\sa next() prev() first() seek() at() isActive() isValid()
*/
bool QSqlQuery::last()
{
if ( !isSelect() || !isActive() )
return FALSE;
beforeSeek();
checkDetach();
bool b = FALSE;
b = d->sqlResult->fetchLast();
afterSeek();
return b;
}
/*!
Returns the size of the result, (number of rows returned), or -1
if the size cannot be determined or if the database does not
support reporting information about query sizes. Note that for
non-\c SELECT statements (isSelect() returns FALSE), size() will
return -1. If the query is not active (isActive() returns FALSE),
-1 is returned.
To determine the number of rows affected by a non-SELECT
statement, use numRowsAffected().
\sa isActive() numRowsAffected() QSqlDriver::hasFeature()
*/
int QSqlQuery::size() const
{
if ( !d->sqlResult )
return -1;
if ( isActive() && d->sqlResult->driver()->hasFeature( QSqlDriver::QuerySize ) )
return d->sqlResult->size();
return -1;
}
/*!
Returns the number of rows affected by the result's SQL statement,
or -1 if it cannot be determined. Note that for \c SELECT
statements, the value is undefined; see size() instead. If the
query is not active (isActive() returns FALSE), -1 is returned.
\sa size() QSqlDriver::hasFeature()
*/
int QSqlQuery::numRowsAffected() const
{
if ( !d->sqlResult )
return -1;
if ( isActive() )
return d->sqlResult->numRowsAffected();
return -1;
}
/*!
Returns error information about the last error (if any) that
occurred.
\sa QSqlError
*/
QSqlError QSqlQuery::lastError() const
{
if ( !d->sqlResult )
return QSqlError();
return d->sqlResult->lastError();
}
/*!
Returns TRUE if the query is currently positioned on a valid
record; otherwise returns FALSE.
*/
bool QSqlQuery::isValid() const
{
if ( !d->sqlResult )
return FALSE;
return d->sqlResult->isValid();
}
/*!
Returns TRUE if the query is currently active; otherwise returns
FALSE.
*/
bool QSqlQuery::isActive() const
{
if ( !d->sqlResult )
return FALSE;
return d->sqlResult->isActive();
}
/*!
Returns TRUE if the current query is a \c SELECT statement;
otherwise returns FALSE.
*/
bool QSqlQuery::isSelect() const
{
if ( !d->sqlResult )
return FALSE;
return d->sqlResult->isSelect();
}
/*!
Returns TRUE if you can only scroll \e forward through a result
set; otherwise returns FALSE.
\sa setForwardOnly()
*/
bool QSqlQuery::isForwardOnly() const
{
if ( !d->sqlResult )
return FALSE;
return d->sqlResult->isForwardOnly();
}
/*!
Sets forward only mode to \a forward. If forward is TRUE only
next(), and seek() with positive values, are allowed for
navigating the results. Forward only mode needs far less memory
since results do not need to be cached.
Forward only mode is off by default.
Forward only mode cannot be used with data aware widgets like
QDataTable, since they must to be able to scroll backward as well
as forward.
\sa isForwardOnly(), next(), seek()
*/
void QSqlQuery::setForwardOnly( bool forward )
{
if ( d->sqlResult )
d->sqlResult->setForwardOnly( forward );
}
/*!
\internal
*/
void QSqlQuery::deref()
{
if ( d->deref() ) {
delete d;
d = 0;
}
}
/*!
\internal
*/
bool QSqlQuery::checkDetach()
{
if ( d->count > 1 && d->sqlResult ) {
QString sql = d->sqlResult->lastQuery();
*this = driver()->createQuery();
exec( sql );
return TRUE;
}
return FALSE;
}
/*!
Protected virtual function called before the internal record
pointer is moved to a new record. The default implementation does
nothing.
*/
void QSqlQuery::beforeSeek()
{
}
/*!
Protected virtual function called after the internal record
pointer is moved to a new record. The default implementation does
nothing.
*/
void QSqlQuery::afterSeek()
{
}
// XXX: Hack to keep BCI - remove in 4.0. QSqlExtension should be
// removed, and the prepare(), exec() etc. fu's should be
// made virtual members of QSqlQuery/QSqlResult
/*!
Prepares the SQL query \a query for execution. The query may
contain placeholders for binding values. Both Oracle style
colon-name (e.g. \c{:surname}), and ODBC style (e.g. \c{?})
placeholders are supported; but they cannot be mixed in the same
query. See the \link #details Description\endlink for examples.
\sa exec(), bindValue(), addBindValue()
*/
bool QSqlQuery::prepare( const QString& query )
{
if ( !d->sqlResult || !d->sqlResult->extension() )
return FALSE;
d->sqlResult->setActive( FALSE );
d->sqlResult->setLastError( QSqlError() );
d->sqlResult->setAt( QSql::BeforeFirst );
d->sqlResult->extension()->clear();
if ( !driver() ) {
#ifdef QT_CHECK_RANGE
qWarning("QSqlQuery::prepare: no driver" );
#endif
return FALSE;
}
if ( d->count > 1 )
*this = driver()->createQuery();
d->sqlResult->setQuery( query.stripWhiteSpace() );
if ( !driver()->isOpen() || driver()->isOpenError() ) {
#ifdef QT_CHECK_RANGE
qWarning("QSqlQuery::prepare: database not open" );
#endif
return FALSE;
}
if ( query.isNull() || query.length() == 0 ) {
#ifdef QT_CHECK_RANGE
qWarning("QSqlQuery::prepare: empty query" );
#endif
return FALSE;
}
#ifdef QT_DEBUG_SQL
qDebug( "\n QSqlQuery: " + query );
#endif
QString q = query;
QRegExp rx(QString::fromLatin1("'[^']*'|:([a-zA-Z0-9_]+)"));
if ( driver()->hasFeature( QSqlDriver::PreparedQueries ) ) {
// below we substitute Oracle placeholders with ODBC ones and
// vice versa to make this db independent
int i = 0, cnt = 0;
if ( driver()->hasFeature( QSqlDriver::NamedPlaceholders ) ) {
QRegExp rx(QString::fromLatin1("'[^']*'|\\?"));
while ( (i = rx.search( q, i )) != -1 ) {
if ( rx.cap(0) == "?" ) {
q = q.replace( i, 1, ":f" + QString::number(cnt) );
cnt++;
}
i += rx.matchedLength();
}
} else if ( driver()->hasFeature( QSqlDriver::PositionalPlaceholders ) ) {
while ( (i = rx.search( q, i )) != -1 ) {
if ( rx.cap(1).isEmpty() ) {
i += rx.matchedLength();
} else {
// record the index of the placeholder - needed
// for emulating named bindings with ODBC
d->sqlResult->extension()->index[ cnt ]= rx.cap(0);
q = q.replace( i, rx.matchedLength(), "?" );
i++;
cnt++;
}
}
}
d->executedQuery = q;
return d->sqlResult->extension()->prepare( q );
} else {
int i = 0;
while ( (i = rx.search( q, i )) != -1 ) {
if ( !rx.cap(1).isEmpty() )
d->sqlResult->extension()->holders.append( Holder( rx.cap(0), i ) );
i += rx.matchedLength();
}
return TRUE; // fake prepares should always succeed
}
}
/*!
\overload
Executes a previously prepared SQL query. Returns TRUE if the
query executed successfully; otherwise returns FALSE.
\sa prepare(), bindValue(), addBindValue()
*/
bool QSqlQuery::exec()
{
bool ret;
if ( !d->sqlResult || !d->sqlResult->extension() )
return FALSE;
if ( driver()->hasFeature( QSqlDriver::PreparedQueries ) ) {
ret = d->sqlResult->extension()->exec();
} else {
// fake preparation - just replace the placeholders..
QString query = d->sqlResult->lastQuery();
if ( d->sqlResult->extension()->bindMethod() == QSqlExtension::BindByName ) {
int i;
QVariant val;
QString holder;
for ( i = (int)d->sqlResult->extension()->holders.count() - 1; i >= 0; --i ) {
holder = d->sqlResult->extension()->holders[ (uint)i ].holderName;
val = d->sqlResult->extension()->values[ holder ].value;
QSqlField f( "", val.type() );
if ( val.isNull() )
f.setNull();
else
f.setValue( val );
query = query.replace( (uint)d->sqlResult->extension()->holders[ (uint)i ].holderPos,
holder.length(), driver()->formatValue( &f ) );
}
} else {
QMap::ConstIterator it;
QString val;
int i = 0;
for ( it = d->sqlResult->extension()->index.begin();
it != d->sqlResult->extension()->index.end(); ++it ) {
i = query.find( '?', i );
if ( i > -1 ) {
QSqlField f( "", d->sqlResult->extension()->values[ it.data() ].value.type() );
if ( d->sqlResult->extension()->values[ it.data() ].value.isNull() )
f.setNull();
else
f.setValue( d->sqlResult->extension()->values[ it.data() ].value );
val = driver()->formatValue( &f );
query = query.replace( i, 1, driver()->formatValue( &f ) );
i += val.length();
}
}
}
// have to retain the original query w/placeholders..
QString orig = d->sqlResult->lastQuery();
ret = exec( query );
d->executedQuery = query;
d->sqlResult->setQuery( orig );
}
d->sqlResult->extension()->resetBindCount();
return ret;
}
/*!
Set the placeholder \a placeholder to be bound to value \a val in
the prepared statement. Note that the placeholder mark (e.g \c{:})
must be included when specifying the placeholder name. If \a type
is \c QSql::Out or \c QSql::InOut, the placeholder will be
overwritten with data from the database after the exec() call.
\sa addBindValue(), prepare(), exec()
*/
void QSqlQuery::bindValue( const QString& placeholder, const QVariant& val, QSql::ParameterType type )
{
if ( !d->sqlResult || !d->sqlResult->extension() )
return;
d->sqlResult->extension()->bindValue( placeholder, val, type );
}
/*!
\overload
Set the placeholder in position \a pos to be bound to value \a val
in the prepared statement. Field numbering starts at 0. If \a type
is \c QSql::Out or \c QSql::InOut, the placeholder will be
overwritten with data from the database after the exec() call.
\sa addBindValue(), prepare(), exec()
*/
void QSqlQuery::bindValue( int pos, const QVariant& val, QSql::ParameterType type )
{
if ( !d->sqlResult || !d->sqlResult->extension() )
return;
d->sqlResult->extension()->bindValue( pos, val, type );
}
/*!
Adds the value \a val to the list of values when using positional
value binding. The order of the addBindValue() calls determines
which placeholder a value will be bound to in the prepared query.
If \a type is \c QSql::Out or \c QSql::InOut, the placeholder will
be overwritten with data from the database after the exec() call.
\sa bindValue(), prepare(), exec()
*/
void QSqlQuery::addBindValue( const QVariant& val, QSql::ParameterType type )
{
if ( !d->sqlResult || !d->sqlResult->extension() )
return;
d->sqlResult->extension()->addBindValue( val, type );
}
/*!
\overload
Binds the placeholder with type \c QSql::In.
*/
void QSqlQuery::bindValue( const QString& placeholder, const QVariant& val )
{
bindValue( placeholder, val, QSql::In );
}
/*!
\overload
Binds the placeholder at position \a pos with type \c QSql::In.
*/
void QSqlQuery::bindValue( int pos, const QVariant& val )
{
bindValue( pos, val, QSql::In );
}
/*!
\overload
Binds the placeholder with type \c QSql::In.
*/
void QSqlQuery::addBindValue( const QVariant& val )
{
addBindValue( val, QSql::In );
}
/*!
Returns the value for the \a placeholder.
*/
QVariant QSqlQuery::boundValue( const QString& placeholder ) const
{
if ( !d->sqlResult || !d->sqlResult->extension() )
return QVariant();
return d->sqlResult->extension()->boundValue( placeholder );
}
/*!
\overload
Returns the value for the placeholder at position \a pos.
*/
QVariant QSqlQuery::boundValue( int pos ) const
{
if ( !d->sqlResult || !d->sqlResult->extension() )
return QVariant();
return d->sqlResult->extension()->boundValue( pos );
}
/*!
Returns a map of the bound values.
The bound values can be examined in the following way:
\code
QSqlQuery query;
...
// Examine the bound values - bound using named binding
QMap::ConstIterator it;
QMap vals = query.boundValues();
for ( it = vals.begin(); it != vals.end(); ++it )
qWarning( "Placeholder: " + it.key() + ", Value: " + (*it).toString() );
...
// Examine the bound values - bound using positional binding
QValueList::ConstIterator it;
QValueList list = query.boundValues().values();
int i = 0;
for ( it = list.begin(); it != list.end(); ++it )
qWarning( "Placeholder pos: %d, Value: " + (*it).toString(), i++ );
...
\endcode
*/
QMap QSqlQuery::boundValues() const
{
if ( !d->sqlResult || !d->sqlResult->extension() )
return QMap();
return d->sqlResult->extension()->boundValues();
}
/*!
Returns the last query that was executed.
In most cases this function returns the same as lastQuery(). If a
prepared query with placeholders is executed on a DBMS that does
not support it, the preparation of this query is emulated. The
placeholders in the original query are replaced with their bound
values to form a new query. This function returns the modified
query. Useful for debugging purposes.
\sa lastQuery()
*/
QString QSqlQuery::executedQuery() const
{
return d->executedQuery;
}
#endif // QT_NO_SQL