crawlservpp::Wrapper::PreparedSqlStatement Class Reference

RAII wrapper for prepared MySQL statements. More...

#include <PreparedSqlStatement.hpp>

Construction and Destruction
	PreparedSqlStatement ()=default
	Default constructor creating an empty statement. More...
	PreparedSqlStatement (sql::Connection *setConnection, std::string_view sqlQuery)
	Constructor preparing a MySQL statement for the given connection and SQL query. More...
virtual	~PreparedSqlStatement ()
	Destructor clearing the prepared MySQL statement if necessary. More...

Getters
sql::PreparedStatement &	get ()
	Gets a reference to the prepared MySQL statement. More...
bool	valid () const noexcept
	Checks whether the prepared MySQL statement is valid. More...

Lifetime
void	prepare ()
	Prepares the MySQL statement. More...
void	clear ()
	Clears the prepared MySQL statement. More...
void	refresh (sql::Connection *newConnection)
	Refreshes the prepared MySQL statement using the new connection given. More...

Copy and Move
The class is not copyable, only moveable.
	PreparedSqlStatement (PreparedSqlStatement &)=delete
	Deleted copy constructor. More...
PreparedSqlStatement &	operator= (PreparedSqlStatement &)=delete
	Deleted copy assignment operator. More...
	PreparedSqlStatement (PreparedSqlStatement &&other) noexcept
	Move constructor. More...
PreparedSqlStatement &	operator= (PreparedSqlStatement &&other) noexcept
	Move assignment operator. More...

Detailed Description

RAII wrapper for prepared MySQL statements.

Prepares the statement on creation and clears it on destruction using a smart pointer, avoiding memory leaks.

Additionally stores the underlying SQL statement as string, to be able to re-create it on connection loss.

At the moment, this class is used exclusively by the Main::Database class.

For more information about the MySQL Connector/C++ used, visit its website.

Note

The class owns the pointer to the prepared MySQL statement.

Constructor & Destructor Documentation

PreparedSqlStatement() [1/4]

crawlservpp::Wrapper::PreparedSqlStatement::PreparedSqlStatement ( )

default

Default constructor creating an empty statement.

Warning

This constructor should only be used for reserving memory, e.g. by using std::vector<PreparedSqlStatement>::resize().

PreparedSqlStatement() [2/4]

crawlservpp::Wrapper::PreparedSqlStatement::PreparedSqlStatement ( sql::Connection *  setConnection, std::string_view  sqlQuery  )

inline

Constructor preparing a MySQL statement for the given connection and SQL query.

Parameters

setConnection	A pointer to the MySQL connection to use.
sqlQuery	A string view containing the SQL query to prepare.

References prepare().

~PreparedSqlStatement()

crawlservpp::Wrapper::PreparedSqlStatement::~PreparedSqlStatement ( )

inlinevirtual

Destructor clearing the prepared MySQL statement if necessary.

References clear().

PreparedSqlStatement() [3/4]

crawlservpp::Wrapper::PreparedSqlStatement::PreparedSqlStatement ( PreparedSqlStatement &  )

delete

Deleted copy constructor.

PreparedSqlStatement() [4/4]

crawlservpp::Wrapper::PreparedSqlStatement::PreparedSqlStatement ( PreparedSqlStatement &&  other )

inlinenoexcept

Move constructor.

Moves the prepared MySQL statement from the specified location into this instance of the class.

Note

The other statement will be invalidated by this move.

Parameters

other

The prepared MySQL statement to move from.

See also

valid

Member Function Documentation

clear()

void crawlservpp::Wrapper::PreparedSqlStatement::clear ( )

inline

Clears the prepared MySQL statement.

The prepared MySQL statement will be invalid and valid() will return false afterwards.

Note

Does nothing if the underlying MySQL statement is not valid.

Referenced by operator=(), prepare(), refresh(), and ~PreparedSqlStatement().

get()

sql::PreparedStatement & crawlservpp::Wrapper::PreparedSqlStatement::get ( )

inline

Gets a reference to the prepared MySQL statement.

Returns

A reference to the prepared MySQL statement.

Exceptions

std::runtime_error

if the MySQL statement is invalid.

operator=() [1/2]

PreparedSqlStatement& crawlservpp::Wrapper::PreparedSqlStatement::operator= ( PreparedSqlStatement &  )

delete

Deleted copy assignment operator.

operator=() [2/2]

PreparedSqlStatement & crawlservpp::Wrapper::PreparedSqlStatement::operator= ( PreparedSqlStatement &&  other )

inlinenoexcept

Move assignment operator.

Moves the prepared MySQL statement from the specified location into this instance of the class.

If there already is a prepared MySQL statement in this instance of the class, it will be cleared.

Note

The other statement will be invalidated by this move.

Nothing will be done if used on itself.

Parameters

other

The prepared MySQL statement to move from.

Returns

A reference to the instance containing the prepared MySQL statement after moving (i.e. *this).

See also

valid

References clear().

prepare()

void crawlservpp::Wrapper::PreparedSqlStatement::prepare ( )

inline

Prepares the MySQL statement.

If a statement has been prepared before, it will be cleared if necessary.

Note

If no SQL query is stored inside this instance of the class, no new MySQL statement will be prepared.

References clear().

Referenced by PreparedSqlStatement(), and refresh().

refresh()

void crawlservpp::Wrapper::PreparedSqlStatement::refresh ( sql::Connection *  newConnection )

inline

Refreshes the prepared MySQL statement using the new connection given.

The old prepared MySQL statement will be cleared before setting the new connection and preparing the same SQL query using the new connection.

This function is used to handle connection losses, which will invalidate the previous connection pointer.

Parameters

newConnection

A pointer to the new connection, which will be used from now on.

References clear(), and prepare().

valid()

bool crawlservpp::Wrapper::PreparedSqlStatement::valid ( ) const

inlinenoexcept

Checks whether the prepared MySQL statement is valid.

Returns

True, if the prepared MySQL statement is valid. False otherwise.

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

• Wrapper/PreparedSqlStatement.hpp