Doctrine_manual-1-2-en

Chapter 10:

Chapter 10: Component Overview 176 Using Expression Values There might be situations where you need to use SQL expressions as values of columns. This can be achieved by using Doctrine_Expression which converts portable DQL expressions to your native SQL expressions. Lets say we have a class called event with columns timepoint(datetime) and name(string). Saving the record with the current timestamp can be achieved as follows: Listing 10-60 // test.php // ... $user = new User(); $user->username = 'jwage'; $user->updated_at = new Doctrine_Expression('NOW()'); $user->save(); The above code would issue the following SQL query: Listing 10-61 INSERT INTO user (username, updated_at_) VALUES ('jwage', NOW()) When you use Doctrine_Expression with your objects in order to get the updated value you will have to manually call refresh() to get the updated value from the database. Listing 10-62 // test.php // ... $user->refresh(); Getting Record State Every Doctrine_Record has a state. First of all records can be transient or persistent. Every record that is retrieved from database is persistent and every newly created record is considered transient. If a Doctrine_Record is retrieved from database but the only loaded property is its primary key, then this record has a state called proxy. Every transient and persistent Doctrine_Record is either clean or dirty. Doctrine_Record is clean when none of its properties are changed and dirty when at least one of its properties has changed. A record can also have a state called locked. In order to avoid infinite recursion in some rare circular reference cases Doctrine uses this state internally to indicate that a record is currently under a manipulation operation. Below is a table containing all the different states a record can be in with a short description of it: Name Doctrine_Record::STATE_PROXY Description Record is in proxy state meaning its persistent but not all of its properties are loaded from the database. Doctrine_Record::STATE_TCLEAN Record is transient clean, meaning its transient and none of its properties are changed. Doctrine_Record::STATE_TDIRTY Record is transient dirty, meaning its transient and some of its properties are changed. Doctrine_Record::STATE_DIRTY Record is dirty, meaning its persistent and some of its properties are changed. ----------------- Brought to you by

Chapter 10: Component Overview 177 Doctrine_Record::STATE_CLEAN Doctrine_Record::STATE_LOCKED Record is locked. Record is clean, meaning its persistent and none of its properties are changed. You can easily get the state of a record by using the Doctrine_Record::state() method: // test.php Listing 10-63 // ... $user = new User(); if ($user->state() == Doctrine_Record::STATE_TDIRTY) { echo 'Record is transient dirty'; } The above object is TDIRTY because it has some default values specified in the schema. If we use an object that has no default values and instantiate a new instance it will return TCLEAN. // test.php Listing 10-64 // ... $account = new Account(); if ($account->state() == Doctrine_Record::STATE_TCLEAN) { echo 'Record is transient clean'; } Getting Object Copy Sometimes you may want to get a copy of your object (a new object with all properties copied). Doctrine provides a simple method for this: Doctrine_Record::copy(). // test.php Listing 10-65 // ... $copy = $user->copy(); Notice that copying the record with copy() returns a new record (state TDIRTY) with the values of the old record, and it copies the relations of that record. If you do not want to copy the relations too, you need to use copy(false). Get a copy of user without the relations // test.php Listing 10-66 // ... $copy = $user->copy(false); Using the PHP clone functionality simply uses this copy() functionality internally: // test.php Listing 10-67 // ... $copy = clone $user; ----------------- Brought to you by