Several flaws were found in a way:1) MySQL handled symbolic links when database tables were created with explicit "DATE" and "INDEX DIRECTORY" options; and2) MySQL's InnoDB engine handled spatial indexes. The risk is LOW. Data destruction - overwrites tables.
Right I have a MYSQL database with table1 with 3 columns, colA, colB and colC. I want to combine the data in the 3 columns into a 4th column names col_comb. Here's the SQL command that works:
UPDATE table1 SET `col_comb` = CONCAT( `colA` , ' - ', `colB` , ', ', `colC` );
So now I want this... (5 Replies)
Apache::Session::Lock::MySQL(3pm) User Contributed Perl Documentation Apache::Session::Lock::MySQL(3pm)NAME
Apache::Session::Lock::MySQL - Provides mutual exclusion using MySQL
SYNOPSIS
use Apache::Session::Lock::MySQL;
my $locker = Apache::Session::Lock::MySQL->new();
$locker->acquire_read_lock($ref);
$locker->acquire_write_lock($ref);
$locker->release_read_lock($ref);
$locker->release_write_lock($ref);
$locker->release_all_locks($ref);
DESCRIPTION
Apache::Session::Lock::MySQL fulfills the locking interface of Apache::Session. Mutual exclusion is achieved through the use of MySQL's
GET_LOCK and RELEASE_LOCK functions. MySQL does not support the notion of read and write locks, so this module only supports exclusive
locks. When you request a shared read lock, it is instead promoted to an exclusive write lock.
CONFIGURATION
The module must know how to connect to your MySQL database to acquire locks. You must provide a datasource name, a user name, and a
password. These options are passed in the usual Apache::Session style, and are very similar to the options for
Apache::Session::Store::MySQL. Example:
tie %hash, 'Apache::Session::MySQL', $id, {
LockDataSource => 'dbi:mysql:database',
LockUserName => 'database_user',
LockPassword => 'K00l'
};
Instead, you may pass in an already opened DBI handle to your database.
tie %hash, 'Apache::Session::MySQL', $id, {
LockHandle => $dbh
};
AUTHOR
This module was written by Jeffrey William Baker <jwbaker@acm.org>.
SEE ALSO
Apache::Session
perl v5.10.1 2010-10-18 Apache::Session::Lock::MySQL(3pm)