MLABSqlDatabase Class Reference

#include <mlabScriptWrappers.h>

Inherits QObject.

Public Slots
SQL connection parameters
void	setHostName (const QString &hostname)
QString	hostName ()
void	setPort (int port)
int	port ()
void	setUserName (const QString &name)
QString	userName ()
void	setPassword (const QString &pwd)
void	setDatabaseName (const QString &name)
QString	databaseName ()
SQL connection
bool	open ()
bool	open (const QString &username, const QString &password)
void	close ()
QMap< QString, QVariant >	lastError ()
bool	isOpen ()
Database information
QStringList	tables ()
bool	supportsTransactions ()
bool	supportsQuerySize ()
QSqlDatabase *	getQSqlDatabase ()
Database transactions
bool	transaction ()
bool	commit ()
bool	rollback ()
SQL query
MLABSqlQuery *	createQuery ()
void	removeQuery (MLABSqlQuery *query)
QVariant	query (const QString &sqlStatement)

Detailed Description

MLABSqlDatabase.

The MLABSqlDatabase object can be used to connect to a SQL database and perform queries on it.

Member Function Documentation

close

void MLABSqlDatabase::close ( )

slot

Closes an open connection.

commit

bool MLABSqlDatabase::commit ( )

slot

Commits the transaction data (returns true on success).

createQuery

MLABSqlQuery * MLABSqlDatabase::createQuery ( )

slot

Creates a new query object.

databaseName

QString MLABSqlDatabase::databaseName ( )

slot

Returns the name of the database.

getQSqlDatabase

QSqlDatabase * MLABSqlDatabase::getQSqlDatabase ( )

inlineslot

Returns the underlying QSqlDatabase instance.

hostName

QString MLABSqlDatabase::hostName ( )

slot

Returns the host name.

isOpen

bool MLABSqlDatabase::isOpen ( )

slot

Returns whether the database is open.

lastError

QMap< QString, QVariant > MLABSqlDatabase::lastError ( )

slot

Returns the last error message as a map.

The map contains:

• message - complete message (type,driverText,databaseText,errorNumber)
• type - type of error
• databaseText
• driverText
• number - error number (depends on driver/database type)

open [1/2]

bool MLABSqlDatabase::open ( )

slot

Opens the connection.

All connections parameters must be set before calling open. Returns true on success.

open [2/2]

bool MLABSqlDatabase::open ( const QString & username, const QString & password )

slot

Opens the connection with given username and password.

All connections parameters must be set before calling open, except for username and password. Returns true on success.

port

int MLABSqlDatabase::port ( )

slot

Returns the port.

query

QVariant MLABSqlDatabase::query ( const QString & sqlStatement )

slot

Performs a query and returns the complete result as a list of records (maps) if the statement is a SELECT; otherwise, it returns the number of affected rows.

• returns a list of records (dict) on a successful SELECT
• returns number of affectedRows on any other statement
• returns -1 on an error

Example that prints the results of a specific select statement:

results = db.query("SELECT username,password from be_users;")
if not results == -1:
  # iterate over all rows
  for result in results:
    # print the username and password of each row
    MLAB.log("username " + result["username"])
    MLAB.log("password " + result["password"])

Example that prints all keys in the result rows of a select statement or the number of affected rows on other statements, assuming that "db" is an opened database:

def printDB(db, sqlStatement):
  result = db.query(sqlStatement)
  if not result == -1:
    # is a select result?
    for row in result:
      for key in row:
        MLAB.log(key)
  else:
    MLAB.log("error in statement")

removeQuery

void MLABSqlDatabase::removeQuery ( MLABSqlQuery * query )

slot

Removes the query object.

rollback

bool MLABSqlDatabase::rollback ( )

slot

Rolls back to the beginning of the transaction (returns true on success).

setDatabaseName

void MLABSqlDatabase::setDatabaseName ( const QString & name )

slot

Sets the name of the database.

setHostName

void MLABSqlDatabase::setHostName ( const QString & hostname )

slot

Sets the host name.

setPassword

void MLABSqlDatabase::setPassword ( const QString & pwd )

slot

Sets the database connection password.

setPort

void MLABSqlDatabase::setPort ( int port )

slot

Sets the port.

setUserName

void MLABSqlDatabase::setUserName ( const QString & name )

slot

Sets the database user name.

supportsQuerySize

bool MLABSqlDatabase::supportsQuerySize ( )

slot

Returns whether the database supports returning the size of a SELECT statement.

supportsTransactions

bool MLABSqlDatabase::supportsTransactions ( )

slot

Returns whether the database supports transactions.

tables

QStringList MLABSqlDatabase::tables ( )

slot

Returns a list of tables of the database (call open() first!).

transaction

bool MLABSqlDatabase::transaction ( )

slot

Starts a transaction (returns true on success).

userName

QString MLABSqlDatabase::userName ( )

slot

Returns the database username.