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Revision as of 02:19, 7 November 2008 by Batch1211
void move ($dirn, [$where = ])
|$dirn||integer||Direction to move the record. $dirn < 0 for up, $dirn > 0 for down.|
|$where||string||Additional where query to limit ordering to a particular subset of records|
Your database table must have a column named 'ordering'.
What does the method do?
The goal of the method is to move a record of the table one step up, or one step down by switching the ordering values with the respective neighbour.
Let's say we have the following database-table:
We now want to move down the entry 'Hello' one step.
//We need an instance of the table object. In a controller or model we can do it like this... $table = $this->getTable('greeting'); //We need to load the 'Hello' entry into the table object. The id (which is the primary key of the table) of this entry is 1. $table->load(1); //We now want to move the 'Hello' entry one step down. That means, the $dirn Parameter must be positive. //We choose the value 1, but it could also be any other positive number $table->move(1);
The first thing the method does is to load the record which has the next higher ordering value. (If our $dirn paremeter would have been negative, it would have loaded the record with the next lower ordering value. In our case, this is the record with the id #4.
The next (and last step) is that the method switches the ordering values of both records. Before:
In the end the table looks like this: