This plugin adds a new administration control panel that can be used to manage constants (key/value pairs) stored in the database. These can then be used in report queries.
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Download the zipped source from here.
Simply install the plugin as normal, and add a table like this to the database:
CREATE TABLE `constants` ( `constant` varchar(255) NOT NULL, `stringval` varchar(255) DEFAULT NULL, `intval` int(11) DEFAULT NULL, `floatval` float DEFAULT NULL, PRIMARY KEY (`constant`) );
You can then use this in report queries. The stringval column will always be stored. intval and floatval will contain the int/float equivalent if possible (i.e. the input could be cast to an int).
Visit the administration panel to update constants.