Doctrine_manual-1-2-en

Chapter 20: Database Abstraction Layer 298
$conn->export->alterTable('events', $alter);
Notice how we renamed the table to event, lets rename it back to events. We only
renamed it to demonstrate the functionality and we will need the table to be named
events for the next examples.
Listing
20-12
// test.php
// ...
$alter = array(
'name' => 'events'
);
$conn->export->alterTable('event', $alter);
Creating Indexes
To create an index, the method createIndex() is used, which has similar signature as
createConstraint(), so it takes table name, index name and a definition array. The
definition array has one key named fields with a value which is another associative array
containing fields that will be a part of the index. The fields are defined as arrays with possible
keys: sorting, with values ascending and descending length, integer value
Not all RDBMS will support index sorting or length, in these cases the drivers will ignore
them. In the test events database, we can assume that our application will show events
occuring in a specific timeframe, so the selects will use the datetime field in WHERE
conditions. It will help if there is an index on this field.
Listing
20-13
// test.php
// ...
$definition = array(
'fields' => array(
'datetime' => array()
)
);
$conn->export->createIndex('events', 'datetime', $definition);
Deleting database elements
For every create*() method as shown above, there is a corresponding drop*() method to
delete a database, a table, field, index or constraint. The drop*() methods do not check if
the item to be deleted exists, so it's developer's responsibility to check for exceptions using a
try catch block:
Listing
20-14
// test.php
// ...
try {
$conn->export->dropSequence('nonexisting');
} catch(Doctrine_Exception $e) {
}
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