q3sqlcursor.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

{
    return d->ftr;
}

/*!
    Sets the name of the cursor to \a name. If \a autopopulate is true
    (the default), the \a name must correspond to a valid table or
    view name in the database. Also, note that all references to the
    cursor edit buffer become invalidated when fields are
    auto-populated. See the Q3SqlCursor constructor documentation for
    more information.
*/
void Q3SqlCursor::setName(const QString& name, bool autopopulate)
{
    d->nm = name;
    if (autopopulate) {
        if (driver()) {
            d->infoBuffer = driver()->record(name);
            *this = d->infoBuffer.toRecord();
            d->editBuffer = *this;
            d->priIndx = driver()->primaryIndex(name);
        }
        if (isEmpty())
            qWarning("Q3SqlCursor::setName: unable to build record, does '%s' exist?", name.latin1());
    }
}

/*!
    Returns the name of the cursor.
*/

QString Q3SqlCursor::name() const
{
    return d->nm;
}

/*! \internal
*/

QString Q3SqlCursor::toString(const QString& prefix, const QString& sep) const
{
    QString pflist;
    QString pfix =  prefix.isEmpty() ? prefix : prefix + ".";
    bool comma = false;

    for (int i = 0; i < count(); ++i) {
        const QString fname = fieldName(i);
        if (isGenerated(i)) {
            if(comma)
                pflist += sep + " ";
            pflist += pfix + fname;
            comma = true;
        }
    }
    return pflist;
}

/*!
  \internal

  Assigns the record \a list.

*/
QSqlRecord & Q3SqlCursor::operator=(const QSqlRecord & list)
{
    return QSqlRecord::operator=(list);
}

/*!
    Append a copy of field \a fieldInfo to the end of the cursor. Note
    that all references to the cursor edit buffer become invalidated.
*/

void Q3SqlCursor::append(const Q3SqlFieldInfo& fieldInfo)
{
    d->editBuffer.append(fieldInfo.toField());
    d->infoBuffer.append(fieldInfo);
    QSqlRecord::append(fieldInfo.toField());
}

/*!
    Removes all fields from the cursor. Note that all references to
    the cursor edit buffer become invalidated.
*/
void Q3SqlCursor::clear()
{
    d->editBuffer.clear();
    d->infoBuffer.clear();
    QSqlRecord::clear();
}


/*!
    Insert a copy of \a fieldInfo at position \a pos. If a field
    already exists at \a pos, it is removed. Note that all references
    to the cursor edit buffer become invalidated.
*/

void  Q3SqlCursor::insert(int pos, const Q3SqlFieldInfo& fieldInfo)
{
    d->editBuffer.replace(pos, fieldInfo.toField());
    d->infoBuffer[pos] = fieldInfo;
    QSqlRecord::replace(pos, fieldInfo.toField());
}

/*!
    Removes the field at \a pos. If \a pos does not exist, nothing
    happens. Note that all references to the cursor edit buffer become
    invalidated.
*/

void Q3SqlCursor::remove(int pos)
{
    d->editBuffer.remove(pos);
    d->infoBuffer[pos] = Q3SqlFieldInfo();
    QSqlRecord::remove(pos);
}

/*!
    Sets the generated flag for the field \a name to \a generated. If
    the field does not exist, nothing happens. Only fields that have
    \a generated set to true are included in the SQL that is
    generated by insert(), update() or del().
*/

void Q3SqlCursor::setGenerated(const QString& name, bool generated)
{
    int pos = indexOf(name);
    if (pos == -1)
        return;
    QSqlRecord::setGenerated(name, generated);
    d->editBuffer.setGenerated(name, generated);
    d->infoBuffer[pos].setGenerated(generated);
}

/*!
    \overload

    Sets the generated flag for the field \a i to \a generated.
*/
void Q3SqlCursor::setGenerated(int i, bool generated)
{
    if (i < 0 || i >= (int)d->infoBuffer.count())
        return;
    QSqlRecord::setGenerated(i, generated);
    d->editBuffer.setGenerated(i, generated);
    d->infoBuffer[i].setGenerated(generated);
}

/*!
    Returns the primary index associated with the cursor as defined in
    the database, or an empty index if there is no primary index. If
    \a setFromCursor is true (the default), the index fields are
    populated with the corresponding values in the cursor's current
    record.
*/

QSqlIndex Q3SqlCursor::primaryIndex(bool setFromCursor) const
{
    if (setFromCursor) {
        for (int i = 0; i < d->priIndx.count(); ++i) {
            const QString fn = d->priIndx.fieldName(i);
            if (contains(fn))
                d->priIndx.setValue(i, QSqlRecord::value(fn));
        }
    }
    return d->priIndx;
}

/*!
    Sets the primary index associated with the cursor to the index \a
    idx. Note that this index must contain a field or set of fields
    which identify a unique record within the underlying database
    table or view so that update() and del() will execute as expected.

    \sa update() del()
*/

void Q3SqlCursor::setPrimaryIndex(const QSqlIndex& idx)
{
    d->priIndx = idx;
}


/*!
    Returns an index composed of \a fieldNames, all in ASCending
    order. Note that all field names must exist in the cursor,
    otherwise an empty index is returned.

    \sa QSqlIndex
*/

QSqlIndex Q3SqlCursor::index(const QStringList& fieldNames) const
{
    QSqlIndex idx;
    for (QStringList::ConstIterator it = fieldNames.begin(); it != fieldNames.end(); ++it) {
        QSqlField f = field((*it));
        if (!f.isValid()) { /* all fields must exist */
            idx.clear();
            break;
        }
        idx.append(f);
    }
    return idx;
}

/*!
    \overload

    Returns an index based on \a fieldName.
*/

QSqlIndex Q3SqlCursor::index(const QString& fieldName) const
{
    QStringList fl(fieldName);
    return index(fl);
}

/*!
    Selects all fields in the cursor from the database matching the
    filter criteria \a filter. The data is returned in the order
    specified by the index \a sort. Returns true if the data was
    successfully selected; otherwise returns false.

    The \a filter is a string containing a SQL \c WHERE clause but
    without the 'WHERE' keyword. The cursor is initially positioned at
    an invalid row after this function is called. To move to a valid
    row, use seek(), first(), last(), previous() or next().

    Example:
    \code
    Q3SqlCursor cur("Employee"); // Use the Employee table or view
    cur.select("deptno=10"); // select all records in department 10
    while(cur.next()) {
        ... // process data
    }
    ...
    // select records in other departments, ordered by department number
    cur.select("deptno>10", cur.index("deptno"));
    ...
    \endcode

    The filter will apply to any subsequent select() calls that do not
    explicitly specify another filter. Similarly the sort will apply
    to any subsequent select() calls that do not explicitly specify
    another sort.

    \code
    Q3SqlCursor cur("Employee");
    cur.select("deptno=10"); // select all records in department 10
    while(cur.next()) {
        ... // process data
    }
    ...
    cur.select(); // re-selects all records in department 10
    ...
    \endcode

*/

bool Q3SqlCursor::select(const QString & filter, const QSqlIndex & sort)
{
    QString fieldList = toString(d->nm);
    if (fieldList.isEmpty())
        return false;
    QString str= "select " + fieldList;
    str += " from " + d->nm;
    if (!filter.isEmpty()) {
        d->ftr = filter;
        str += " where " + filter;
    } else
        d->ftr = QString();
    if (sort.count() > 0)
        str += " order by " + sort.toString(d->nm);
    d->srt = sort;
    return exec(str);
}

/*!
    \overload

    Selects all fields in the cursor from the database. The rows are
    returned in the order specified by the last call to setSort() or
    the last call to select() that specified a sort, whichever is the
    most recent. If there is no current sort, the order in which the
    rows are returned is undefined. The records are filtered according
    to the filter specified by the last call to setFilter() or the
    last call to select() that specified a filter, whichever is the
    most recent. If there is no current filter, all records are
    returned. The cursor is initially positioned at an invalid row. To
    move to a valid row, use seek(), first(), last(), previous() or
    next().

    \sa setSort() setFilter()
*/

bool Q3SqlCursor::select()
{
    return select(filter(), sort());
}

/*!
    \overload

    Selects all fields in the cursor from the database. The data is
    returned in the order specified by the index \a sort. The records
    are filtered according to the filter specified by the last call to
    setFilter() or the last call to select() that specified a filter,
    whichever is the most recent. The cursor is initially positioned
    at an invalid row. To move to a valid row, use seek(), first(),
    last(), previous() or next().
*/

bool Q3SqlCursor::select(const QSqlIndex& sort)
{
    return select(filter(), sort);
}

/*!
    \overload

    Selects all fields in the cursor matching the filter index \a
    filter. The data is returned in the order specified by the index
    \a sort. The \a filter index works by constructing a WHERE clause
    using the names of the fields from the \a filter and their values
    from the current cursor record. The cursor is initially positioned
    at an invalid row. To move to a valid row, use seek(), first(),
    last(), previous() or next(). This function is useful, for example,
    for retrieving data based upon a table's primary index:

    \code
    Q3SqlCursor cur("Employee");
    QSqlIndex pk = cur.primaryIndex();
    cur.setValue("id", 10);
    cur.select(pk, pk); // generates "SELECT ... FROM Employee WHERE id=10 ORDER BY id"
    ...
    \endcode

    In this example the QSqlIndex, pk, is used for two different
    purposes. When used as the filter (first) argument, the field
    names it contains are used to construct the WHERE clause, each set
    to the current cursor value, \c{WHERE id=10}, in this case. When
    used as the sort (second) argument the field names it contains are
    used for the ORDER BY clause, \c{ORDER BY id} in this example.
*/

bool Q3SqlCursor::select(const QSqlIndex & filter, const QSqlIndex & sort)
{
    return select(toString(filter, this, d->nm, "=", "and"), sort);
}

/*!
    Sets the cursor mode to \a mode. This value can be an OR'ed
    combination of \l Q3SqlCursor::Mode values. The default mode for a
    cursor is Q3SqlCursor::Writable.

    \code
    Q3SqlCursor cur("Employee");
    cur.setMode(Q3SqlCursor::Writable); // allow insert/update/delete
    ...
    cur.setMode(Q3SqlCursor::Insert | Q3SqlCursor::Update); // allow inserts and updates only
    ...
    cur.setMode(Q3SqlCursor::ReadOnly); // no inserts/updates/deletes allowed

    \endcode
*/

void Q3SqlCursor::setMode(int mode)
{
    d->md = mode;
}

/*!
    Returns the current cursor mode.

    \sa setMode()
*/

int Q3SqlCursor::mode() const
{
    return d->md;
}

/*!
    Sets field \a name to \a calculated. If the field \a name does not
    exist, nothing happens. The value of a calculated field is set by
    the calculateField() virtual function which you must reimplement
    (or the field value will be an invalid QVariant). Calculated
    fields do not appear in generated SQL statements sent to the
    database.

    \sa calculateField()
*/