58 lines
1.6 KiB
PHP
58 lines
1.6 KiB
PHP
Doctrine Query Language(DQL) is an Object Query Language created for helping users in complex object retrieval.
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You should always consider using DQL(or raw SQL) when retrieving relational data efficiently (eg. when fetching users and their phonenumbers).
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When compared to using raw SQL, DQL has several benefits:
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* From the start it has been designed to retrieve records(objects) not result set rows
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* DQL understands relations so you don't have to type manually sql joins and join conditions
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* DQL is portable on different databases
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* DQL has some very complex built-in algorithms like (the record limit algorithm) which can help
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developer to efficiently retrieve objects
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* It supports some functions that can save time when dealing with one-to-many, many-to-many relational data with conditional fetching.
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If the power of DQL isn't enough, you should consider using the rawSql API for object population.
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<code type="php">
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// DO NOT USE THE FOLLOWING CODE
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// (using many sql queries for object population):
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$users = $conn->getTable('User')->findAll();
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foreach($users as $user) {
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print $user->name."
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";
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foreach($user->Phonenumber as $phonenumber) {
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print $phonenumber."
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";
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}
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}
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// same thing implemented much more efficiently:
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// (using only one sql query for object population)
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$users = $conn->query("FROM User.Phonenumber");
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foreach($users as $user) {
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print $user->name."
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";
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foreach($user->Phonenumber as $phonenumber) {
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print $phonenumber."
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";
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}
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}
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</code>
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