Database Utility Class

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

Initializing the Utility Class

Important

In order to initialize the Utility class, your database driver must already be running, since the utilities class relies on it.

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.

Note

Both of the parameters can be used individually, just pass an empty value as the first one if you wish to skip it.

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...
}

Note

Replace database_name with the name of the database you are looking for. This method is case sensitive.

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!';
}

Note

Not all database platforms support table optimization. It is mostly for use with MySQL.

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!';
}

Note

Not all database platforms support table repairs.

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);
}

Note

Not all database platforms support database optimization. It it is mostly for use with MySQL.

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);

Important

This method will NOT write the CSV file for you. It simply creates the CSV layout. If you need to write the file use the File Helper.

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);

Important

This method will NOT write the XML file for you. It simply creates the XML layout. If you need to write the file use the File Helper.

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.

Note

This feature is only available for MySQL and Interbase/Firebird databases.

Note

For Interbase/Firebird databases, the backup file name is the only parameter.

$this->dbutil->backup(‘db_backup_filename’);

Note

Due to the limited execution time and memory available to PHP, backing up very large databases may not be possible. If your database is very large you might need to backup directly from your SQL server via the command line, or have your server admin do it for you if you do not have root privileges.

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.