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+--- Thread: Check for database connection (/showthread.php?tid=36295)
Check for database connection - El Forum - 11-27-2010
[eluser]pshah.mumbai[/eluser]
I have created a custom library called "Startup" which checks/loads/initializes all the basic things that I need to have in the application.
I need to do some custom handling if the database connection is not correct. The DB_driver class throws a exception and completely kills off the application. So I have set the db_debug flag to FALSE in database.php file.
Code:
$db['default']['db_debug'] = FALSE;And in the Startup library it checks if the connection is valid.
Code:
class Startup
{
function Startup()
{
$CI =& get_instance();
if ( ! $CI->db->conn_id) // HERE LIES THE PROBLEM
redirect("install");The problem is $CI->db->conn_id just checks if it is able to connect to server i.e. hostname, ports are valid. It does not tell if the username/password/dbname is valid or not. Is there any $CI->db method that tells that the username/password/dbname is valid ?
Check for database connection - El Forum - 11-27-2010
[eluser]pshah.mumbai[/eluser]
One ugly solution is $CI->db->query("SHOW TABLES"); If it returns NULL then there is some issue with the connection.
Check for database connection - El Forum - 11-27-2010
[eluser]InsiteFX[/eluser]
If I am not mistaken the Database will not connect if the user id and password are wrong!
InsiteFX
Check for database connection - El Forum - 11-27-2010
[eluser]pshah.mumbai[/eluser]
Quote:If I am not mistaken the Database will not connect if the user id and password are wrong!
That is true if $db['default']['db_debug'] = TRUE - it will throw an exception. But if $db['default']['db_debug'] = FALSE then it will silently fail. Now if I want to manually check for a valid connection then there is no way to do it.
The $this->db->conn_id will be set if it is able to open connection to database. It does not indicate a valid database/username/password.
Below is the code from database/DB_driver.php
Code:
function initialize()
{
// If an existing connection resource is available
// there is no need to connect and select the database
if (is_resource($this->conn_id) OR is_object($this->conn_id))
{
return TRUE;
}
// ----------------------------------------------------------------
// Connect to the database and set the connection ID
$this->conn_id = ($this->pconnect == FALSE) ? $this->db_connect() : $this->db_pconnect();
// No connection resource? Throw an error
if ( ! $this->conn_id)
{
log_message('error', 'Unable to connect to the database');
if ($this->db_debug)
{
$this->display_error('db_unable_to_connect');
}
return FALSE;
}
// ----------------------------------------------------------------
// Select the DB... assuming a database name is specified in the config file
if ($this->database != '')
{
if ( ! $this->db_select())
{
log_message('error', 'Unable to select database: '.$this->database);
if ($this->db_debug)
{
$this->display_error('db_unable_to_select', $this->database);
}
return FALSE;
}
else
{
// We've selected the DB. Now we set the character set
if ( ! $this->db_set_charset($this->char_set, $this->dbcollat))
{
return FALSE;
}
return TRUE;
}
}
return TRUE;
}