Database Utility Class

The Database Utility Class contains methods that help you manage your database.

• Initializing the Utility Class
• Using the Database Utilities
  • Retrieve list of database names
  • Determine If a Database Exists
  • Optimize a Table
  • Repair a Table
  • Optimize a Database
  • Export a Query Result as a CSV File
  • Export a Query Result as an XML Document
• Backup Your Database
  • Database Backup Notes
  • Usage Example
  • Setting Backup Preferences
  • Description of Backup Preferences
• Class Reference

Initializing the Utility Class

Load the Utility Class as follows:

$this->load->dbutil();

You can also pass another database object to the DB Utility loader, in case the database you want to manage isn’t the default one:

$this->myutil = $this->load->dbutil($this->other_db, TRUE);

In the above example, we’re passing a custom database object as the first parameter and then tell it to return the dbutil object, instead of assigning it directly to $this->dbutil.

Once initialized you will access the methods using the $this->dbutil object:

$this->dbutil->some_method();

Using the Database Utilities

Retrieve list of database names

Returns an array of database names:

$dbs = $this->dbutil->list_databases();

foreach ($dbs as $db)
{
        echo $db;
}

Determine If a Database Exists

Sometimes it’s helpful to know whether a particular database exists. Returns a boolean TRUE/FALSE. Usage example:

if ($this->dbutil->database_exists('database_name'))
{
        // some code...
}

Optimize a Table

Permits you to optimize a table using the table name specified in the first parameter. Returns TRUE/FALSE based on success or failure:

if ($this->dbutil->optimize_table('table_name'))
{
        echo 'Success!';
}

Repair a Table

Permits you to repair a table using the table name specified in the first parameter. Returns TRUE/FALSE based on success or failure:

if ($this->dbutil->repair_table('table_name'))
{
        echo 'Success!';
}

Optimize a Database

Permits you to optimize the database your DB class is currently connected to. Returns an array containing the DB status messages or FALSE on failure.

$result = $this->dbutil->optimize_database();

if ($result !== FALSE)
{
        print_r($result);
}

Export a Query Result as a CSV File

Permits you to generate a CSV file from a query result. The first parameter of the method must contain the result object from your query. Example:

$this->load->dbutil();

$query = $this->db->query("SELECT * FROM mytable");

echo $this->dbutil->csv_from_result($query);

The second, third, and fourth parameters allow you to set the delimiter newline, and enclosure characters respectively. By default commas are used as the delimiter, “n” is used as a new line, and a double-quote is used as the enclosure. Example:

$delimiter = ",";
$newline = "\r\n";
$enclosure = '"';

echo $this->dbutil->csv_from_result($query, $delimiter, $newline, $enclosure);

Export a Query Result as an XML Document

Permits you to generate an XML file from a query result. The first parameter expects a query result object, the second may contain an optional array of config parameters. Example:

$this->load->dbutil();

$query = $this->db->query("SELECT * FROM mytable");

$config = array (
        'root'          => 'root',
        'element'       => 'element',
        'newline'       => "\n",
        'tab'           => "\t"
);

echo $this->dbutil->xml_from_result($query, $config);

Backup Your Database

Database Backup Notes

Permits you to backup your full database or individual tables. The backup data can be compressed in either Zip or Gzip format.

Usage Example

// Load the DB utility class
$this->load->dbutil();

// Backup your entire database and assign it to a variable
$backup = $this->dbutil->backup();

// Load the file helper and write the file to your server
$this->load->helper('file');
write_file('/path/to/mybackup.gz', $backup);

// Load the download helper and send the file to your desktop
$this->load->helper('download');
force_download('mybackup.gz', $backup);

Setting Backup Preferences

Backup preferences are set by submitting an array of values to the first parameter of the backup() method. Example:

$prefs = array(
        'tables'        => array('table1', 'table2'),   // Array of tables to backup.
        'ignore'        => array(),                     // List of tables to omit from the backup
        'format'        => 'txt',                       // gzip, zip, txt
        'filename'      => 'mybackup.sql',              // File name - NEEDED ONLY WITH ZIP FILES
        'add_drop'      => TRUE,                        // Whether to add DROP TABLE statements to backup file
        'add_insert'    => TRUE,                        // Whether to add INSERT data to backup file
        'newline'       => "\n"                         // Newline character used in backup file
);

$this->dbutil->backup($prefs);

Description of Backup Preferences

Preference	Default Value	Options	Description
tables	empty array	None	An array of tables you want backed up. If left blank all tables will be exported.
ignore	empty array	None	An array of tables you want the backup routine to ignore.
format	gzip	gzip, zip, txt	The file format of the export file.
filename	the current date/time	None	The name of the backed-up file. The name is needed only if you are using zip compression.
add_drop	TRUE	TRUE/FALSE	Whether to include DROP TABLE statements in your SQL export file.
add_insert	TRUE	TRUE/FALSE	Whether to include INSERT statements in your SQL export file.
newline	“\n”	“\n”, “\r”, “\r\n”	Type of newline to use in your SQL export file.
foreign_key_checks	TRUE	TRUE/FALSE	Whether output should keep foreign key checks enabled.

Class Reference

class CI_DB_utility

backup([$params = array()])

Parameters:	$params (array) – An associative array of options
Returns:	raw/(g)zipped SQL query string
Return type:	string

Perform a database backup, per user preferences.

database_exists($database_name)

Parameters:	$database_name (string) – Database name
Returns:	TRUE if the database exists, FALSE otherwise
Return type:	bool

Check for the existence of a database.

list_databases()

Returns:	Array of database names found
Return type:	array

Retrieve a list of all the database names.

optimize_database()

Returns:	Array of optimization messages or FALSE on failure
Return type:	array

Optimizes the database.

optimize_table($table_name)

Parameters:	$table_name (string) – Name of the table to optimize
Returns:	Array of optimization messages or FALSE on failure
Return type:	array

Optimizes a database table.

repair_table($table_name)

Parameters:	$table_name (string) – Name of the table to repair
Returns:	Array of repair messages or FALSE on failure
Return type:	array

Repairs a database table.

csv_from_result($query[, $delim = ', '[, $newline = "n"[, $enclosure = '"']]])

Parameters:	$query (object) – A database result object $delim (string) – The CSV field delimiter to use $newline (string) – The newline character to use $enclosure (string) – The enclosure delimiter to use
Returns:	The generated CSV file as a string
Return type:	string

Translates a database result object into a CSV document.

xml_from_result($query[, $params = array()])

Parameters:	$query (object) – A database result object $params (array) – An associative array of preferences
Returns:	The generated XML document as a string
Return type:	string

Translates a database result object into an XML document.