private function execute( $sql )
{
  return $this->mysqli->query ( $sql );
}
/**
 * I save the entire database schema to a local xml file.
 *
 * @param [string] $database the name of your database
 * @return [result] true or false
 */
public function saveSchemaXML( $database )
{
	$dom = new DOMDocument ( '1.0' );
	
	/************************************
	 * Builds the root 
	 ************************************/
	//create a element
	$schema = $dom->createElement ( 'schema' );
	//set the element on itself
	$schema = $dom->appendChild ( $schema );
	//set a attribute for the schema node 
	$schema->setAttribute ( 'name', $database );
	
	/***********************************
	 * Builds the table inside the root
	 **********************************/
	$tableQuery = $this->execute ( "SHOW TABLES FROM $database" );
	
	while ( $tableRow = mysqli_fetch_row ( $tableQuery ) )
	{
		//create a element
		$table = $dom->createElement ( 'table' );
		//set the element on itself
		$table = $dom->appendChild ( $table );
		//set a attribute
		$table->setAttribute ( 'name', $tableRow [ 0 ] );
		
		$fieldQuery = $this->execute ( "DESCRIBE $database.$tableRow[0]" );
		
		while ( $fieldRow = mysqli_fetch_assoc ( $fieldQuery ) )
		{
			/***********************************
			 * Builds the attributes inside the table
			 **********************************/
			//create a element
			$field = $dom->createElement ( 'field' );
			//set the element on itself
			$field = $dom->appendChild ( $field );
			//set the name attribute
			$field->setAttribute ( 'name', $fieldRow [ 'Field' ] );
			//set the type attribute
			$field->setAttribute ( 'type', $this->replaceNumbers ( $fieldRow [ 'Type' ] ) );
			//set the null attribute
			$field->setAttribute ( 'null', strtolower ( $fieldRow [ 'Null' ] ) );
			
			if ( $fieldRow [ 'Default' ] != '' )
			{
				//set the default
				$field->setAttribute ( 'default', strtolower ( $fieldRow [ 'Default' ] ) );
			}
			if ( $fieldRow [ 'Key' ] != '' )
			{
				//set the key
				$field->setAttribute ( 'key', strtolower ( $fieldRow [ 'Key' ] ) );
			}
			if ( $fieldRow [ 'Extra' ] != '' )
			{
				//set the value/length attribute
				$field->setAttribute ( 'extra', strtolower ( $fieldRow [ 'Extra' ] ) );
			}
			
			//put the field inside of the table
			$table->appendChild ( $field );
		}
		
		//put the table inside of the schema
		$schema->appendChild ( $table );
	}
	
	$dom->formatOutput = true;
	$dom->saveXML ();
	$filename = 'output/' . ucfirst ( $database ) . 'Schema.xml';
	
	//save the file
	$xml = $dom->save ( $filename );
	
	//change the permissions
	chmod ( "$filename", 0777 );
	
	return $xml;
}

Export entire database schema to local xml file.

MySQL Schema XML Export

mysql, php, xml

PHP