更新查询在Joomla中不起作用

Question

I'm working on a joomla extension and I'm trying to update entries in my joomla extensions database table using the following code in my model:

$this->_db->setQuery(
    $this->_db->getQuery(true)
    ->update('#__my_table')
    ->set('position=position+1')
);
$dbres = $this->_db->result();

However it doesn't do anything and outputs no error (Development on and error reporting maximum in global config)

I entered the query directly in PHPmyAdmin:

UPDATE cprn7_my_table SET position=position+1

and it works without any problems. I read about quoting keys and values with $this->_db->quoteName() or so, but I can't find any examples for that with queries like SET position=position+1 but only SET position=$newval so I don't know exactly what to quote and how.

//EDIT: Found the error, it has to be $this->_db->query() and not $this->_db->result()

Answer 1

A few possibilities come to mind. The first is that the --safe-updates setting is enabled, preventing updates (and deletes) whose WHERE clause lacks a primary key column specification.

phpMyAdmin may turn this setting off, while your default MySQL client settings (in my.cnf , under [client] ) may be enabling it. You can use the show variables statement to discover the setting's value. Also, see this doc for more info: http://dev.mysql.com/doc/refman/5.5/en/mysql-command-options.html#option_mysql_safe-updates

A second thought: You can quote the column name using backticks, for example:

SET `position`=`position` + 1

However, if this still seems to have no effect, and, if you have an admin-level MySQL account for your server, you can turn the general log on, then run your query, then turn it off again, then examine your results. See this doc for working with the --general-log and related settings: http://dev.mysql.com/doc/refman/5.5/en/query-log.html

BTW, if your MySQL client provider (or Joomla, or any other tier in the mix) is setting --safe-updates using a SET command (ie, upon connecting), you will also see this as an executed statement in the general log.