En informatique, et plus précisément dans le domaine des base de données, un plan d’exécution est un schéma pas à pas des opérations d’accès aux données d ‘un système de gestion de base de données SQL. Les mots clés à inclure dans les requêtes SQL pour influencer le plan d’exécution sont appelés les hints (ou. Cet article ou cette section ne s’appuie pas, ou pas assez, sur des sources secondaires ou tertiaires (janvier ). Pour améliorer la vérifiabilité de l’article ou. 22 févr. Les requêtes récursives permettent d’éviter le recours à des procédures stockées , lorsqu’il s’agit d’afficher les valeurs par niveau d’une.
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In order to make this mapping possible, you need to describe to Doctrine what columns in the result map to which entity property. This description is represented by a ResultSetMapping object. With this feature you sal map arbitrary SQL code rwquetes objects, such as highly vendor-optimized SQL or stored-procedures. Use EntityManager getConnection to access the native database connection and call the executeUpdate method for these queries. As you can see in the tequetes of this method, it expects 2 ingredients: Once you obtained an instance of a NativeQueryyou can bind parameters to it with the same API that Query has and execute it.
This has several benefits:. The builder extends the ResultSetMapping class and as such has all the functionality of it as well. Starting with Doctrine ORM 2. A Doctrine result can contain the following components:.
As the query gets parsed and transformed to SQL, Doctrine fills a ResultSetMapping that describes how the results should be processed by the hydration routines. An entity result describes an entity type that appears as a root element in the transformed result. lws
Let’s take a look at the method signature in detail:. The first parameter is the fully qualified name of the entity class. The second parameter is some arbitrary alias for this entity result that must be unique within a ResultSetMapping.
Utilisation avancée de sqlmap
You use this alias to attach field results to the entity result. It is very similar to an identification variable that you use in DQL to alias classes or relationships. An entity result alone is not enough to form a valid ResultSetMapping. An entity result or joined entity result always needs a set of field results, which we will look at soon.
A joined entity result describes an entity type that appears as a joined relationship element in the transformed result, attached to a root entity result. The first parameter is the class name of the joined entity. The second parameter is an arbitrary alias for the joined entity that must be unique within the ResultSetMapping.
The third parameter is the alias of the entity result that is the parent type of the joined relationship. The fourth and last parameter is the name of the field on the parent entity result that should contain the joined entity result.
A field result describes the mapping of a single column in a SQL result set to a field in an entity. As such, field results are inherently bound to entity results.
Again, let’s examine the method signature in detail:. The first parameter is the alias of the entity result to which the field result will belong. The second parameter is the name of the column in the SQL result set. Note that this name is case sensitive, i. A scalar result describes the mapping of a single column in a SQL result set to a scalar value in the Doctrine result.
Scalar results are typically used for aggregate values but any column in the SQL result set can be mapped as a scalar value. The method signature in detail:. The first parameter is the name of the lee in the SQL result set and the second parameter is the result alias under which the value of the column will be placed in the transformed Doctrine result.
A meta result describes a single column in a SQL result set that is either a foreign key or a discriminator column. These columns are essential for Doctrine to properly construct objects out of SQL result sets.
The first parameter is the alias of the entity result to which the meta column belongs. A meta result column foreign key or discriminator column always belongs to an entity result. The fourth parameter should be set to true in case the primary key of the entity is the foreign key you’re adding. When joining an inheritance tree you have to give Doctrine a hint which meta-column is the discriminator column of this tree.
Note that this would be a partial object if the entity has more fields than just id and name. In the example above the column and field names are identical but that is not necessary, of course.
Doctrine does not touch this SQL in any way. In the previous basic example, a User had no relations and the table the class is mapped to owns no foreign keys. The next example assumes User has a unidirectional or bidirectional one-to-one association to a CmsAddress, where the User is the owning side and thus owns the foreign key.
Foreign keys are used by Doctrine for lazy-loading purposes when querying for objects.
When zql ghost proxy is accessed, it loads itself based on this key. Consequently, associations that are fetch-joined do not require the foreign keys to be present in the SQL result set, only associations that are lazy. In this case the nested entity Address is registered with the ResultSetMapping addJoinedEntityResult method, which notifies Doctrine that this entity is not hydrated at the root level, but as a joined entity somewhere inside the object graph.
DatabaseSpy Outil de base de données multiple | Altova
In this case we specify aql alias ‘u’ as third parameter and address as fourth parameter, which means the Address is hydrated into the User:: If a fetched entity is part of a mapped hierarchy that requires a discriminator column, this column must be present in the result set as a meta column so that Doctrine can create the appropriate concrete type.
This is shown in the following example where we assume that there are one or more subclasses that extend User and either Class Table Inheritance or Single Table Inheritance is used to map the hierarchy both use a discriminator column. Note that in the case of Class Table Inheritance, an example as above would result in partial objects if any objects in the result are actually a subtype of User.
When using DQL, Doctrine automatically includes the necessary joins for this mapping strategy but with native SQL it is your responsibility. To achieve that, you must describe the SQL resultset structure using named native query and sql resultset mappings if is a several resultset mappings. In the above example, the fetchJoinedAddress named query use the joinMapping result set mapping. This mapping returns 2 entities, User and Address, each property is kes and associated to a column name, actually the column name retrieved by the query.
In this example, we only describe rdquetes entity member of the result set mapping. If the association to a related entity involve a composite primary key, a FieldResult element should be used for each foreign key column.
Java Bla-Bla: JPA – Tracer les requêtes SQL avec Log4jdbc
The FieldResult name is composed of the property name for the relationship, followed by a dot “. If you retrieve a single entity and if you use the default mapping, you can use the resultClass attribute sq, of resultSetMapping:.
In some of your native queries, you’ll have to return scalar values, for example when building report queries. You actually can even mix, entities and scalar returns in the same native query this is probably not that common though.
Entity Classes How can I add default values to a column? How can I filter an association? I call clear on a One-To-Many collection but the entities are not deleted How can I add columns to a many-to-many table?
How can i paginate fetch-joined collections? Why does pagination not work correctly with fetch joins? Inheritance Can I use Inheritance with Doctrine 2?
Why does Doctrine not create proxy objects for my inheritance hierarchy? Why does the EntityGenerator not generate inheritance correctly? Performance Why is an extra SQL dql executed every time I ls an entity with a one-to-one relation?
A Query fails, how can I debug it? Oes should I force partial objects? Table of Contents 2. New in version 2.
User owns no associations.