Joomla! Programmierung/Framework/JDatabase

JDatabase ist eine abstrakte Klasse, die von spezifischen Datenbanktreibern erweitert wird. JDatabase stellt Datenbankverbindungen für Joomla! zur Verfügung.

Definiert in

 /libraries/joomla

•  database
  •  database.php

Status

• @since

Erweitert

JObject

Erweitert von

• JDatabaseMySQL
• JDatabaseMySQLi

Importieren

jimport( 'joomla.database.database' );

Methoden

ToDo übersetzen Properties which do not have specific get or set methods listed here can be retrieved or set using the inherited JObject->get method.

Name	Beschreibung
addQuoted	Adds a field or array of field names to the list that are to be quoted.
BeginTrans	ADODB compatibility function.
CommitTrans	ADODB compatibility function.
connected	Determines if the connection to the server is active.
debug	Sets the debug level on or off.
ErrorMsg	ADODB compatibility function.
ErrorNo	ADODB compatibility function.
Execute	ADODB compatibility function.
explain	Diagnostic function.
GenID	ADODB compatibility function.
getAffectedRows	Get the number of rows affected by the most recent query.
GetCol	ADODB compatibility function.
getCollation	Get the database collation.
getConnectors	Get the database connectors.
getErrorMsg	Get the error message.
getErrorNum	Get the error number.
getEscaped	Get a database escaped string.
getInstance	Returns a reference to the global database object, only creating it if it doesn't already exist.
getLog	Get a database error log.
getNullDate	Get the database null date.
getNumRows	Get the number of rows returned by the most recent query.
GetOne	ADODB compatibility function.
getPrefix	Get the database table prefix.
getQuery	Get the active query.
GetRow	ADODB compatibility function.
getTableCreate	Shows the CREATE TABLE statement that creates the given tables.
getTableFields	Retrieves information about the given tables.
getTableList	Lists tables in a database.
getTicker	Get the total number of queries made.
getUTFSupport	Get the database UTF-8 support.
getVersion	Get the version of the database connector.
hasUTF	Determines UTF support.
insertid	Gets the ID generated from the previous INSERT operation.
insertObject	Inserts a row into a table based on an objects properties.
isQuoted	Checks if field name needs to be quoted.
loadAssoc	Fetch a result row as an associative array.
loadAssocList	Loads an associative list of database rows.
loadObject	Loads the first row of a query into an object.
loadObjectList	Loads a list of database objects.
Joomla!_Programmierung/Framework/JDatabase/loadResult	Loads the first field of the first row returned by the query.
loadResultArray	Loads an array of single field results into an array.
loadRow	Loads the first row returned by the query.
loadRowList	Loads a list of database rows (numeric column indexing).
nameQuote	Quote an identifier name (field, table, etc.).
PageExecute	ADODB compatibility function.
query	Execute the query.
queryBatch	Execute a batch query.
Quote	Get a quoted database escaped string.
replacePrefix	Replaces a string identifier $prefix with the string held is the _table_prefix class variable.
RollbackTrans	ADODB compatibility function.
SelectLimit	ADODB compatibility function.
setQuery	Sets the SQL query string for later execution.
setUTF	Custom settings for UTF support.
splitSql	Splits a string of queries into an array of individual queries.
stderr	Prints out an error statement.
test	Tests to see if the connector is available.
updateObject	Updates an object in the database.

Beispiele

Einen Dump der kompletten Datenbank erstellen

In diesem Beispiel kommen Methoden der JDatabase Klasse zum Einsatz, die hilfreich beim Erstellen von Datenbankdumps sind.

Zum Beispiel erzeugt die Methode getTableCreate() einen kompletten CREATE TABLE SQL String.

/**
 * Erstellt einen komletten Dump der Datenbank
 * @static
 */
class DbBackUp
{
    /**
     * Erstellt einen komletten Dump der Datenbank
     *
     * @return string Dump der Datenbank
     */
    public static function backupDB()
    {
        //-- New line character
        defined('NL') or define('NL', "\n");
 
        //-- Referenz auf das JDatabase Objekt erzeugen
        $db = JFactory::getDBO();
 
        //-- Eine Liste aller Tabellen der Datenbank erstellen
        $tabellen = $db->getTableList();
 
        $s = '';
 
        foreach($tabellen as $tablenName)
        {
            $s .= self::getTableDump($tablenName);
        }//foreach
 
        return $s;
    }//function
 
    /**
     * Erstellt einen Dump einer einzelnen Tabelle
     *
     * @param $tableName string Name der Tabelle
     * @return string Dump der Tabelle
     */
    private static function getTableDump($tableName)
    {
        //-- Referenz auf das JDatabase Objekt erzeugen
        $db = JFactory::getDBO();
 
        //-- Eine "CREATE TABLE" SQL Anweisung erzeugen
        $createString = $db->getTableCreate($tableName);
 
        //-- Einlesen der Feldnamen
        $tFields = $db->getTableColumns($tableName, false);
 
        //-- Einlesen der Daten
        $db->setQuery('SELECT * FROM '.$tableName);
        $rows = $db->loadAssocList();
 
        $s = '';
        $s .= '-- -----------------------------------------------'.NL;
        $s .= '-- Table structure for table '.$tableName.NL;
        $s .= '--'.NL;
        $s .= $createString[$tableName].';'.NL;
 
        //-- Wenn die Tabelle Daten enthält diese hizufügen
        if(count($rows))
        {
            //-- "INSERT" Anweisungen generieren
            $s .= '--'.NL;
            $s .= '-- Data for table '.$tableName.NL;
            $s .= '--'.NL;
            $s .= 'INSERT INTO `'.$tableName.'`'.NL;
            $s .= '  (`'.implode('`, `', array_keys($rows[0])).'`)'.NL;
            $s .= 'VALUES'.NL;
 
            $r = array();
            foreach ($rows as $row)
            {
                $l = array();
                foreach ($row as $k => $v)
                {
                    //-- Falls es kein integer ist, muss der Wert gequotet werden
                    $l[] =(strpos($tFields[$k]->Type, 'int') !== false) ? $v : $db->quote($v);
                }//foreach
 
                $r[] = '  ('.implode(', ', $l).')';
            }//foreach
 
            $s .= implode(','.NL, $r).';'.NL;
        }
 
        $s .= '-- -----------------------------------------------'.NL.NL;
 
        return $s;
    }//function
 
}//class

Hier werden die Struktur und die Daten aller Tabellen der Datenbank eingelesen und SQL Anweisungen generiert, die zum Beispiel in Backup-Programmen verwendet werden können.

Der Aufruf erfolgt statisch mit

$dbDump = DbBackUp::backupDB();

Die Variable $dbDump enthält danach einen Standard Datenbank Dump in Form eines Strings.

zum Beispiel:

   ...
...
 -------------------------------------------------
 -- Table structure for table jos_hello
 --
 CREATE TABLE `jos_hello` (
 `id` int(11) NOT NULL auto_increment,
 `greeting` varchar(25) NOT NULL,
 PRIMARY KEY  (`id`)
 ) TYPE=MyISAM AUTO_INCREMENT=5;
 --
 -- Data for table jos_hello
 --
 INSERT INTO `jos_hello`
 (`id`, `greeting`)
 VALUES
 (1, 'Hello, World!'),
 (2, 'Bonjour, Monde!'),
 (3, 'Ciao, Mondo!'),
 (4, 'Hallo, Welt ;)');
 -------------------------------------------------

 -------------------------------------------------
 -- Table structure for table jos_....
   ...

Verwendete Methoden: getTableCreate(), getTableFields(), setQuery(), loadAssocList(), quote(), getTableList()

Siehe auch

• http://docs.joomla.org/How_to_use_the_database_classes_in_your_script
• JDatabase auf api.joomla.org
• Joomla!_Programmierung/Framework/JDatabaseMySQL
• Joomla!_Programmierung/Framework/JDatabaseMySQLi