#include <Wt/Dbo/backend/MySQL.h>

Inheritance diagram for Wt::Dbo::backend::MySQL:

Public Member Functions
	MySQL (const std::string &db, const std::string &dbuser="root", const std::string &dbpasswd="", const std::string dbhost="localhost", unsigned int dbport=0, const std::string &dbsocket="/var/run/mysqld/mysqld.sock", int fractionalSecondsPart=-1)
	Opens a new MySQL backend connection. More...

	MySQL (const MySQL &other)
	Copies a MySQL connection. More...

	~MySQL ()
	Destructor. More...

virtual std::unique_ptr< SqlConnection >	clone () const override
	Returns a copy of the connection.

bool	connect (const std::string &db, const std::string &dbuser="root", const std::string &dbpasswd="", const std::string &dbhost="localhost", unsigned int dbport=0, const std::string &dbsocket="/var/run/mysqld/mysqld.sock")
	Tries to connect. More...

MySQL_impl *	connection ()
	Returns the underlying connection.

virtual void	executeSql (const std::string &sql) override
	Executes an SQL statement. More...

virtual void	startTransaction () override
	Starts a transaction. More...

virtual void	commitTransaction () override
	Commits a transaction. More...

virtual void	rollbackTransaction () override
	Rolls back a transaction. More...

virtual std::unique_ptr< SqlStatement >	prepareStatement (const std::string &sql) override
	Prepares a statement. More...

int	getFractionalSecondsPart () const
	Returns the supported fractional seconds part. More...

void	setFractionalSecondsPart (int fractionalSecondsPart)
	Set the supported fractional seconds part. More...

Methods that return dialect information
virtual std::string	autoincrementSql () const override
	Returns the 'autoincrement' SQL type modifier. More...

virtual std::string	autoincrementType () const override
	Returns the 'autoincrement' SQL type. More...

virtual std::string	autoincrementInsertSuffix (const std::string &id) const override
	Returns the suffix for an 'autoincrement' insert statement. More...

virtual std::vector< std::string >	autoincrementCreateSequenceSql (const std::string &table, const std::string &id) const override
	Returns the SQL statement(s) required to create an id sequence. More...

virtual std::vector< std::string >	autoincrementDropSequenceSql (const std::string &table, const std::string &id) const override
	Returns the SQL statement(s) required to drop an id sequence. More...

virtual const char *	dateTimeType (SqlDateTimeType type) const override
	Returns the date/time type. More...

virtual const char *	blobType () const override
	Returns the blob type. More...

virtual bool	supportAlterTable () const override
	Returns true if the backend support Alter Table. More...

virtual const char *	alterTableConstraintString () const override
	Returns the command used in alter table .. drop constraint .. More...

virtual bool	requireSubqueryAlias () const override
	Returns the true if the database require subquery alias. More...

Public Member Functions inherited from Wt::Dbo::SqlConnection
virtual	~SqlConnection ()
	Destructor.

virtual SqlStatement *	getStatement (const std::string &id) const
	Returns the statement with the given id. More...

virtual void	saveStatement (const std::string &id, std::unique_ptr< SqlStatement > statement)
	Saves a statement with the given id. More...

void	setProperty (const std::string &name, const std::string &value)
	Sets a property. More...

std::string	property (const std::string &name) const
	Returns a property. More...

virtual std::string	autoincrementInsertInfix (const std::string &id) const
	Returns the infix for an 'autoincrement' insert statement. More...

virtual void	prepareForDropTables ()
	Execute code before dropping the tables. More...

virtual std::string	textType (int size) const
	Returns the text type. More...

virtual std::string	longLongType () const
	Returns the 64-bit integer type. More...

virtual const char *	booleanType () const
	Returns the boolean type. More...

virtual bool	supportUpdateCascade () const
	Returns true if the database supports Update Cascade. More...

virtual LimitQuery	limitQueryMethod () const
	Returns the 'autoincrement' SQL type modifier. More...

virtual bool	usesRowsFromTo () const
	Returns whether the SQL dialect uses 'ROWS ? TO ?', limit or rownum for partial select results. More...

virtual bool	supportDeferrableFKConstraint () const
	Returns true if the backend supports "deferrable initially deferred" foreign key constraints. More...

Detailed Description

A MySQL connection.

This class provides the backend implementation for mariadb databases. It has been tested against MySQL 5.6.

In order to work properly with Wt::Dbo, MySQL must be configured with InnoDB (for MySQL) or XtraDB (for mariadb) as the default database engine - so that the transaction based functionality works.

Note: There is a bug in the implementation of milliseconds in mariadb C client which affects WTime and posix::time_duration values – it goes berserk when fractional part = 0.

Constructor & Destructor Documentation

Wt::Dbo::backend::MySQL::MySQL	(	const std::string &	db,
		const std::string &	dbuser = `"root"`,
		const std::string &	dbpasswd = `""`,
		const std::string	dbhost = `"localhost"`,
		unsigned int	dbport = `0`,
		const std::string &	dbsocket = `"/var/run/mysqld/mysqld.sock"`,
		int	fractionalSecondsPart = `-1`
	)

Opens a new MySQL backend connection.

For the connection parameter description, please refer to the connect() method.

Parameters

fractionalSecondsPart The number of fractional units (0 to 6). A value of -1 indicates that the fractional part is not stored. Fractional seconds part are supported for MySQL 5.6.4 http://dev.mysql.com/doc/refman/5.6/en/fractional-seconds.html

Wt::Dbo::backend::MySQL::MySQL ( const MySQL & other )

Copies a MySQL connection.

This creates a new connection with the same settings as another connection.

See also: clone()

Wt::Dbo::backend::MySQL::~MySQL ( )

Destructor.

Closes the connection.

Member Function Documentation

const char * Wt::Dbo::backend::MySQL::alterTableConstraintString ( ) const

overridevirtual

Returns the command used in alter table .. drop constraint ..

This method will return "constraint" by default. Default: ALTER TABLE .. DROP CONSTRAINT ..

Reimplemented from Wt::Dbo::SqlConnection.

std::vector< std::string > Wt::Dbo::backend::MySQL::autoincrementCreateSequenceSql	(	const std::string &	table,
		const std::string &	id
	)		const

overridevirtual

Returns the SQL statement(s) required to create an id sequence.

This is used by Session::createTables() to create the id sequence for a table. The table's name and primary key are passed as arguments to this function and can be used to construct an SQL sequence that is unique for the table.

Implements Wt::Dbo::SqlConnection.

std::vector< std::string > Wt::Dbo::backend::MySQL::autoincrementDropSequenceSql	(	const std::string &	table,
		const std::string &	id
	)		const

overridevirtual

Returns the SQL statement(s) required to drop an id sequence.

This is used by Session::dropTables() to drop the id sequence for a table. The table's name and primary key are passed as arguments to this function and can be used to construct an SQL sequence that is unique for the table.

Implements Wt::Dbo::SqlConnection.

std::string Wt::Dbo::backend::MySQL::autoincrementInsertSuffix ( const std::string & id ) const

overridevirtual

Returns the suffix for an 'autoincrement' insert statement.

This is appended to the insert statement, since some back-ends need to be indicated that they should return the autoincrement id.

Implements Wt::Dbo::SqlConnection.

std::string Wt::Dbo::backend::MySQL::autoincrementSql ( ) const

overridevirtual

Returns the 'autoincrement' SQL type modifier.

This is used by Session::createTables() to create the id column.

Implements Wt::Dbo::SqlConnection.

std::string Wt::Dbo::backend::MySQL::autoincrementType ( ) const

overridevirtual

Returns the 'autoincrement' SQL type.

This is used by Session::createTables() to create the id column.

Implements Wt::Dbo::SqlConnection.

const char * Wt::Dbo::backend::MySQL::blobType ( ) const

overridevirtual

Returns the blob type.

See also: SqlStatement::bind(int, const std::vector<unsigned char>&)

Implements Wt::Dbo::SqlConnection.

void Wt::Dbo::backend::MySQL::commitTransaction ( )

overridevirtual

Commits a transaction.

This function commits a transaction.

Implements Wt::Dbo::SqlConnection.

bool Wt::Dbo::backend::MySQL::connect	(	const std::string &	db,
		const std::string &	dbuser = `"root"`,
		const std::string &	dbpasswd = `""`,
		const std::string &	dbhost = `"localhost"`,
		unsigned int	dbport = `0`,
		const std::string &	dbsocket = `"/var/run/mysqld/mysqld.sock"`
	)

Tries to connect.

Parameters

db	The database name.
dbuser	The username for the database connection - defaults to "root".
dbpasswd	The password for the database conection - defaults to an empty string.
dbhost	The hostname of the database - defaults to localhost.
dbport	The portnumber - defaults to a default port.
dbsocket	The socket to use.

Throws an exception if there was a problem, otherwise true.

const char * Wt::Dbo::backend::MySQL::dateTimeType ( SqlDateTimeType type ) const

overridevirtual

Returns the date/time type.

See also: SqlStatement::bind(int, const std::chrono::system_clock::time_point&, SqlDateTimeType)

Implements Wt::Dbo::SqlConnection.

void Wt::Dbo::backend::MySQL::executeSql ( const std::string & sql )

overridevirtual

Executes an SQL statement.

This is a convenience method for preparing a statement, executing it, and deleting it.

Reimplemented from Wt::Dbo::SqlConnection.

int Wt::Dbo::backend::MySQL::getFractionalSecondsPart ( ) const

Returns the supported fractional seconds part.

By default return -1: fractional part is not stored. Fractional seconds part is supported for MySQL 5.6.4 http://dev.mysql.com/doc/refman/5.6/en/fractional-seconds.html

See also: setFractionalSecondsPart()

std::unique_ptr< SqlStatement > Wt::Dbo::backend::MySQL::prepareStatement ( const std::string & sql )

overridevirtual

Prepares a statement.

Returns the prepared statement.

Implements Wt::Dbo::SqlConnection.

virtual bool Wt::Dbo::backend::MySQL::requireSubqueryAlias ( ) const

overridevirtual

Returns the true if the database require subquery alias.

This method will return false by default.

Reimplemented from Wt::Dbo::SqlConnection.

void Wt::Dbo::backend::MySQL::rollbackTransaction ( )

overridevirtual

Rolls back a transaction.

This function rolls back a transaction.

Implements Wt::Dbo::SqlConnection.

void Wt::Dbo::backend::MySQL::setFractionalSecondsPart ( int fractionalSecondsPart )

Set the supported fractional seconds part.

The fractional seconds part can be also set in the constructor Fractional seconds part is supported for MySQL 5.6.4 http://dev.mysql.com/doc/refman/5.6/en/fractional-seconds.html

Parameters

fractionalSecondsPart Must be in the range 0 to 6.

See also: setFractionalSecondsPart()

void Wt::Dbo::backend::MySQL::startTransaction ( )

overridevirtual

Starts a transaction.

This function starts a transaction.

Implements Wt::Dbo::SqlConnection.

bool Wt::Dbo::backend::MySQL::supportAlterTable ( ) const

overridevirtual

Returns true if the backend support Alter Table.

This method will return false by default.

Reimplemented from Wt::Dbo::SqlConnection.

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation