#include <qsqlnulldriver_p.h>

Inheritance diagram for QSqlNullResult:

Collaboration diagram for QSqlNullResult:

Public Member Functions
	QSqlNullResult (const QSqlDriver *d)

Public Member Functions inherited from QSqlResult
virtual	~QSqlResult ()
	Destroys the object and frees any allocated resources.

virtual QVariant	handle () const
	Returns the low-level database handle for this result set wrapped in a QVariant or an invalid QVariant if there is no handle.

Protected Member Functions
QVariant	data (int) override
	Returns the data for field index in the current row as a QVariant.

bool	reset (const QString &) override
	Sets the result to use the SQL statement query for subsequent data retrieval.

bool	fetch (int) override
	Positions the result to an arbitrary (zero-based) row index.

bool	fetchFirst () override
	Positions the result to the first record (row 0) in the result.

bool	fetchLast () override
	Positions the result to the last record (last row) in the result.

bool	isNull (int) override
	Returns `true` if the field at position index in the current row is null; otherwise returns `false`.

int	size () override
	Returns the size of the `SELECT` result, or -1 if it cannot be determined or if the query is not a `SELECT` statement.

int	numRowsAffected () override
	Returns the number of rows affected by the last query executed, or -1 if it cannot be determined or if the query is a `SELECT` statement.

void	setAt (int) override
	This function is provided for derived classes to set the internal (zero-based) row position to index.

void	setActive (bool) override
	This function is provided for derived classes to set the internal active state to active.

void	setLastError (const QSqlError &) override
	This function is provided for derived classes to set the last error to error.

void	setQuery (const QString &) override
	Sets the current query for the result to query.

void	setSelect (bool) override
	This function is provided for derived classes to indicate whether or not the current statement is a SQL `SELECT` statement.

void	setForwardOnly (bool) override
	Sets forward only mode to forward.

bool	exec () override
	Executes the query, returning true if successful; otherwise returns false.

bool	prepare (const QString &) override
	Prepares the given query for execution; the query will normally use placeholders so that it can be executed repeatedly.

bool	savePrepare (const QString &) override
	Prepares the given query, using the underlying database functionality where possible.

void	bindValue (int, const QVariant &, QSql::ParamType) override
	Binds the value val of parameter type paramType to position index in the current record (row).

void	bindValue (const QString &, const QVariant &, QSql::ParamType) override
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Binds the value val of parameter type paramType to the placeholder name in the current record (row).

Protected Member Functions inherited from QSqlResult
	QSqlResult (const QSqlDriver *db)
	Creates a QSqlResult using database driver db.

	QSqlResult (QSqlResultPrivate &dd)

int	at () const
	Returns the current (zero-based) row position of the result.

QString	lastQuery () const
	Returns the current SQL query text, or an empty string if there isn't one.

QSqlError	lastError () const
	Returns the last error associated with the result.

bool	isValid () const
	Returns `true` if the result is positioned on a valid record (that is, the result is not positioned before the first or after the last record); otherwise returns `false`.

bool	isActive () const
	Returns `true` if the result has records to be retrieved; otherwise returns `false`.

bool	isSelect () const
	Returns `true` if the current result is from a `SELECT` statement; otherwise returns `false`.

bool	isForwardOnly () const
	Returns `true` if you can only scroll forward through the result set; otherwise returns `false`.

const QSqlDriver *	driver () const
	Returns the driver associated with the result.

virtual void	setAt (int at)
	This function is provided for derived classes to set the internal (zero-based) row position to index.

virtual void	setActive (bool a)
	This function is provided for derived classes to set the internal active state to active.

virtual void	setLastError (const QSqlError &e)
	This function is provided for derived classes to set the last error to error.

virtual void	setQuery (const QString &query)
	Sets the current query for the result to query.

virtual void	setSelect (bool s)
	This function is provided for derived classes to indicate whether or not the current statement is a SQL `SELECT` statement.

virtual void	setForwardOnly (bool forward)
	Sets forward only mode to forward.

virtual bool	exec ()
	Executes the query, returning true if successful; otherwise returns false.

virtual bool	prepare (const QString &query)
	Prepares the given query for execution; the query will normally use placeholders so that it can be executed repeatedly.

virtual bool	savePrepare (const QString &sqlquery)
	Prepares the given query, using the underlying database functionality where possible.

virtual void	bindValue (int pos, const QVariant &val, QSql::ParamType type)
	Binds the value val of parameter type paramType to position index in the current record (row).

virtual void	bindValue (const QString &placeholder, const QVariant &val, QSql::ParamType type)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Binds the value val of parameter type paramType to the placeholder name in the current record (row).

void	addBindValue (const QVariant &val, QSql::ParamType type)
	Binds the value val of parameter type paramType to the next available position in the current record (row).

QVariant	boundValue (const QString &placeholder) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Returns the value bound by the given placeholder name in the current record (row).

QVariant	boundValue (int pos) const
	Returns the value bound at position index in the current record (row).

QSql::ParamType	bindValueType (const QString &placeholder) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Returns the parameter type for the value bound with the given placeholder name.

QSql::ParamType	bindValueType (int pos) const
	Returns the parameter type for the value bound at position index.

int	boundValueCount () const
	Returns the number of bound values in the result.

QVariantList &	boundValues (QT6_DECL_NEW_OVERLOAD)

QVariantList	boundValues (QT6_DECL_NEW_OVERLOAD) const

QString	executedQuery () const
	Returns the query that was actually executed.

QStringList	boundValueNames () const
	Returns the names of all bound values.

QString	boundValueName (int pos) const
	Returns the name of the bound value at position index in the current record (row).

void	clear ()
	Clears the entire result set and releases any associated resources.

bool	hasOutValues () const
	Returns `true` if at least one of the query's bound values is a `QSql::Out` or a QSql::InOut; otherwise returns `false`.

BindingSyntax	bindingSyntax () const
	Returns the binding syntax used by prepared queries.

virtual QVariant	data (int i)=0
	Returns the data for field index in the current row as a QVariant.

virtual bool	isNull (int i)=0
	Returns `true` if the field at position index in the current row is null; otherwise returns `false`.

virtual bool	reset (const QString &sqlquery)=0
	Sets the result to use the SQL statement query for subsequent data retrieval.

virtual bool	fetch (int i)=0
	Positions the result to an arbitrary (zero-based) row index.

virtual bool	fetchNext ()
	Positions the result to the next available record (row) in the result.

virtual bool	fetchPrevious ()
	Positions the result to the previous record (row) in the result.

virtual bool	fetchFirst ()=0
	Positions the result to the first record (row 0) in the result.

virtual bool	fetchLast ()=0
	Positions the result to the last record (last row) in the result.

virtual int	size ()=0
	Returns the size of the `SELECT` result, or -1 if it cannot be determined or if the query is not a `SELECT` statement.

virtual int	numRowsAffected ()=0
	Returns the number of rows affected by the last query executed, or -1 if it cannot be determined or if the query is a `SELECT` statement.

virtual QSqlRecord	record () const
	Returns the current record if the query is active; otherwise returns an empty QSqlRecord.

virtual QVariant	lastInsertId () const
	Returns the object ID of the most recent inserted row if the database supports it.

virtual void	virtual_hook (int id, void *data)

virtual bool	execBatch (bool arrayBind=false)

virtual void	detachFromResultSet ()

virtual void	setNumericalPrecisionPolicy (QSql::NumericalPrecisionPolicy policy)

QSql::NumericalPrecisionPolicy	numericalPrecisionPolicy () const

virtual bool	nextResult ()

void	resetBindCount ()
	Resets the number of bind parameters.

Additional Inherited Members
Protected Types inherited from QSqlResult
enum	BindingSyntax { PositionalBinding , NamedBinding }
	This enum type specifies the different syntaxes for specifying placeholders in prepared queries. More...

enum	VirtualHookOperation

Protected Attributes inherited from QSqlResult
QSqlResultPrivate *	d_ptr

Detailed Description

Definition at line 26 of file qsqlnulldriver_p.h.

Constructor & Destructor Documentation

◆ QSqlNullResult()

QSqlNullResult::QSqlNullResult ( const QSqlDriver * d )

inlineexplicit

Definition at line 29 of file qsqlnulldriver_p.h.

References QSqlError::ConnectionError, and QSqlResult::setLastError().

Here is the call graph for this function:

Member Function Documentation

◆ bindValue() [1/2]

void QSqlNullResult::bindValue	(	const QString &	placeholder,
		const QVariant &	val,
		QSql::ParamType	paramType
	)

inlineoverrideprotectedvirtual

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.Binds the value val of parameter type paramType to the placeholder name in the current record (row).

Note: Binding an undefined placeholder will result in undefined behavior.

See also: QSqlQuery::bindValue()

Reimplemented from QSqlResult.

Definition at line 53 of file qsqlnulldriver_p.h.

◆ bindValue() [2/2]

void QSqlNullResult::bindValue	(	int	index,
		const QVariant &	val,
		QSql::ParamType	paramType
	)

inlineoverrideprotectedvirtual

Binds the value val of parameter type paramType to position index in the current record (row).

See also: addBindValue()

Reimplemented from QSqlResult.

Definition at line 52 of file qsqlnulldriver_p.h.

◆ data()

QVariant QSqlNullResult::data ( int index )

inlineoverrideprotectedvirtual

Returns the data for field index in the current row as a QVariant.

This function is only called if the result is in an active state and is positioned on a valid record and index is non-negative. Derived classes must reimplement this function and return the value of field index, or QVariant() if it cannot be determined.

Implements QSqlResult.

Definition at line 33 of file qsqlnulldriver_p.h.

◆ exec()

bool QSqlNullResult::exec ( )

inlineoverrideprotectedvirtual

Executes the query, returning true if successful; otherwise returns false.

See also: prepare()

Reimplemented from QSqlResult.

Definition at line 49 of file qsqlnulldriver_p.h.

◆ fetch()

bool QSqlNullResult::fetch ( int index )

inlineoverrideprotectedvirtual

Positions the result to an arbitrary (zero-based) row index.

This function is only called if the result is in an active state. Derived classes must reimplement this function and position the result to the row index, and call setAt() with an appropriate value. Return true to indicate success, or false to signify failure.

See also: isActive(), fetchFirst(), fetchLast(), fetchNext(), fetchPrevious()

Implements QSqlResult.

Definition at line 35 of file qsqlnulldriver_p.h.

◆ fetchFirst()

bool QSqlNullResult::fetchFirst ( )

inlineoverrideprotectedvirtual

Positions the result to the first record (row 0) in the result.

This function is only called if the result is in an active state. Derived classes must reimplement this function and position the result to the first record, and call setAt() with an appropriate value. Return true to indicate success, or false to signify failure.

See also: fetch(), fetchLast()

Implements QSqlResult.

Definition at line 36 of file qsqlnulldriver_p.h.

◆ fetchLast()

bool QSqlNullResult::fetchLast ( )

inlineoverrideprotectedvirtual

Positions the result to the last record (last row) in the result.

This function is only called if the result is in an active state. Derived classes must reimplement this function and position the result to the last record, and call setAt() with an appropriate value. Return true to indicate success, or false to signify failure.

See also: fetch(), fetchFirst()

Implements QSqlResult.

Definition at line 37 of file qsqlnulldriver_p.h.

◆ isNull()

bool QSqlNullResult::isNull ( int i )

inlineoverrideprotectedvirtual

Returns true if the field at position index in the current row is null; otherwise returns false.

Implements QSqlResult.

Definition at line 38 of file qsqlnulldriver_p.h.

◆ numRowsAffected()

int QSqlNullResult::numRowsAffected ( )

inlineoverrideprotectedvirtual

Returns the number of rows affected by the last query executed, or -1 if it cannot be determined or if the query is a SELECT statement.

See also: size()

Implements QSqlResult.

Definition at line 40 of file qsqlnulldriver_p.h.

◆ prepare()

bool QSqlNullResult::prepare ( const QString & query )

inlineoverrideprotectedvirtual

Prepares the given query for execution; the query will normally use placeholders so that it can be executed repeatedly.

Returns true if the query is prepared successfully; otherwise returns false.

See also: exec()

Reimplemented from QSqlResult.

Definition at line 50 of file qsqlnulldriver_p.h.

◆ reset()

bool QSqlNullResult::reset ( const QString & query )

inlineoverrideprotectedvirtual

Sets the result to use the SQL statement query for subsequent data retrieval.

Derived classes must reimplement this function and apply the query to the database. This function is only called after the result is set to an inactive state and is positioned before the first record of the new result. Derived classes should return true if the query was successful and ready to be used, or false otherwise.

See also: setQuery()

Implements QSqlResult.

Definition at line 34 of file qsqlnulldriver_p.h.

◆ savePrepare()

bool QSqlNullResult::savePrepare ( const QString & query )

inlineoverrideprotectedvirtual

Prepares the given query, using the underlying database functionality where possible.

Returns true if the query is prepared successfully; otherwise returns false.

Note: This method should have been called "safePrepare()".

See also: prepare()

Reimplemented from QSqlResult.

Definition at line 51 of file qsqlnulldriver_p.h.

◆ setActive()

void QSqlNullResult::setActive ( bool active )

inlineoverrideprotectedvirtual

This function is provided for derived classes to set the internal active state to active.

See also: isActive()

Reimplemented from QSqlResult.

Definition at line 43 of file qsqlnulldriver_p.h.

◆ setAt()

void QSqlNullResult::setAt ( int index )

inlineoverrideprotectedvirtual

This function is provided for derived classes to set the internal (zero-based) row position to index.

See also: at()

Reimplemented from QSqlResult.

Definition at line 42 of file qsqlnulldriver_p.h.

◆ setForwardOnly()

void QSqlNullResult::setForwardOnly ( bool forward )

inlineoverrideprotectedvirtual

Sets forward only mode to forward.

If forward is true, only fetchNext() is allowed for navigating the results. Forward only mode needs much less memory since results do not have to be cached. By default, this feature is disabled.

Setting forward only to false is a suggestion to the database engine, which has the final say on whether a result set is forward only or scrollable. isForwardOnly() will always return the correct status of the result set.

Note: Calling setForwardOnly after execution of the query will result in unexpected results at best, and crashes at worst.; To make sure the forward-only query completed successfully, the application should check lastError() for an error not only after executing the query, but also after navigating the query results.

Warning: PostgreSQL: While navigating the query results in forward-only mode, do not execute any other SQL command on the same database connection. This will cause the query results to be lost.

See also: isForwardOnly(), fetchNext(), QSqlQuery::setForwardOnly()

Reimplemented from QSqlResult.

Definition at line 47 of file qsqlnulldriver_p.h.

◆ setLastError()

void QSqlNullResult::setLastError ( const QSqlError & error )

inlineoverrideprotectedvirtual

This function is provided for derived classes to set the last error to error.

See also: lastError()

Reimplemented from QSqlResult.

Definition at line 44 of file qsqlnulldriver_p.h.

◆ setQuery()

void QSqlNullResult::setQuery ( const QString & query )

inlineoverrideprotectedvirtual

Sets the current query for the result to query.

You must call reset() to execute the query on the database.

See also: reset(), lastQuery()

Reimplemented from QSqlResult.

Definition at line 45 of file qsqlnulldriver_p.h.

◆ setSelect()

void QSqlNullResult::setSelect ( bool select )

inlineoverrideprotectedvirtual

This function is provided for derived classes to indicate whether or not the current statement is a SQL SELECT statement.

The select parameter should be true if the statement is a SELECT statement; otherwise it should be false.

See also: isSelect()

Reimplemented from QSqlResult.

Definition at line 46 of file qsqlnulldriver_p.h.

◆ size()

int QSqlNullResult::size ( )

inlineoverrideprotectedvirtual

Returns the size of the SELECT result, or -1 if it cannot be determined or if the query is not a SELECT statement.

See also: numRowsAffected()

Implements QSqlResult.

Definition at line 39 of file qsqlnulldriver_p.h.

The documentation for this class was generated from the following file:

qtbase/src/sql/kernel/qsqlnulldriver_p.h

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QSqlNullResult()

Member Function Documentation

◆ bindValue() [1/2]

◆ bindValue() [2/2]

◆ data()

◆ exec()

◆ fetch()

◆ fetchFirst()

◆ fetchLast()

◆ isNull()

◆ numRowsAffected()

◆ prepare()

◆ reset()

◆ savePrepare()

◆ setActive()

◆ setAt()

◆ setForwardOnly()

◆ setLastError()

◆ setQuery()

◆ setSelect()

◆ size()