How to Write Sql Query in Doctrine Where to Check Two Values Are Equal or Not

Databases and the Doctrine ORM

Interpretation: 2.7

• Maintained versions
  • 4.4
  • 5.3
  • 5.4
  • 6.0 current
  • 6.1 dev
• Unmaintained versions
  • 2.7
  • 2.8
  • 3.0
  • 3.1
  • 3.2
  • 3.3
  • 3.4
  • 4.0
  • 4.1
  • 4.2
  • 4.3
  • 5.0
  • 5.1
  • 5.2

Edit this page

• A Simple Example: A Product
  • Configuring the Database
  • Creating an Entity Classify
  • Tote up Chromosome mapping Information
  • Generating Getters and Setters
  • Creating the Database Tables/Outline
  • Persisting Objects to the Database
  • Fetching Objects from the Database
  • Updating an Targe
  • Deleting an Object
• Querying for Objects
  • Querying for Objects with DQL
  • Querying for Objects Using Doctrine's Query Builder
  • Organizing Custom Queries into Repository Classes
• Conformation
• Doctrine Field Types Reference
• Relationships and Associations
• Final Thoughts
• Learn more

Hold over of Contents

Databases and the Doctrine ORM

One of the most common and challenging tasks for any application involves persisting and interpretation information to and from a database. Although the Symfony Framework doesn't integrate any component to work with databases, information technology provides tight integration with a 3rd-company subroutine library called Ism. Doctrine's sole finish is to give you almighty tools to make database interactions easy and flexible.

Therein chapter, you'll learn how to start leveraging Philosophical system in your Symfony projects to give you rich database interactions.

Note

Doctrine is totally decoupled from Symfony and using information technology is optional. This chapter is complete about the Doctrine ORM, which aims to LET you map objects to a relative database (such as MySQL, PostgreSQL Oregon Microsoft SQL). If you opt to use raw database queries, this is well-heeled, and explained in the "How to Use Doctrine DBAL" article.

You can as wel persist data to MongoDB using Doctrine ODM library. For more information, read the "`DoctrineMongoDBBundle`_" documentation.

A Simple Exemplar: A Product

The easiest way to understand how Doctrine works is to see information technology in process. In this department, you'll configure your database, make over a Product targe, persist it to the database and bring it pull in one's horns.

Configuring the Database

Before you truly begin, you'll demand to configure your database connection information. By convention, this information is usually configured in an app/config/parameters.yml file:

Note

Shaping the contour via parameters.yml is just a conventionality. The parameters distinct in this file are documented by the main contour file when setting risen Doctrine:

• YAML
• XML
• PHP

By separating the database information into a separate file, you stool easily keep incompatible versions of the file on each server. You can as wel easily store database configuration (or any sensitive information) outdoors of your jut, like inside your Apache form, e.g.. For more information, see How to Set external Parameters in the Service Container.

Now that Doctrine fanny connect to your database, the following command can automatically generate an void test_project database for you:

Note

If you want to use SQLite as your database, you postulate to mark the path where your database file cabinet should be stored:

• YAML
• XML
• PHP

Creating an Entity Year

Suppose you're building an application where products penury to beryllium displayed. Without even off thinking nigh School of thought or databases, you already have it off that you need a Product object to represent those products. Create this class internal the Entity directory of your AppBundle:

The class - often known as an "entity", import a basic assort that holds data - is simple and helps fulfill the business enterprise requirement of needing products in your application. This class can't be persisted to a database yet - it's just a simple PHP form.

Tip

Formerly you discover the concepts behind Doctrine, you can have Doctrine create simple entity classes for you. This will ask you mutual questions to help you build any entity:

Add Mapping Information

Doctrine allows you to work with databases in a much more interesting way of life than just fetching rows of musical notation data into an array. Alternatively, Doctrine allows you to fetch entire objects verboten of the database, and to persist entire objects to the database. For Philosophy to be capable to do this, you must map your database tables to specific PHP classes, and the columns on those tables must be mapped to peculiar properties on their corresponding PHP classes.

You'll allow for this mapping data in the form of "metadata", a collection of rules that tells Doctrine exactly how the Product class and its properties should be mapped to a specific database table. This metadata can be specified in a figure of assorted formats, including YAML, XML or flat inside the Product class via DocBlock annotations:

• Annotations
• YAML
• XML

Note of hand

A practice bundling can accept exclusive one metadata definition format. For representative, it's not possible to mix YAML metadata definitions with annotated PHP entity class definitions.

Lead

The table name is elective and if omitted, testament be settled mechanically supported the name of the entity class.

Doctrine allows you to choose from a wide variety of different field types, each with their ain options. For data on the available field types, go steady the Databases and the Doctrine ORM section.

Project besides

You give the sack also check out Doctrine's Basic Mapping Documentation for complete details about mapping data. If you use annotations, you'll need to prepend wholly annotations with ORM\ (e.g. ORM\Column(...)), which is not shown in Doctrine's documentation. You'll too need to include the use Doctrine\ORM\Mapping as ORM; statement, which imports the ORM annotations prefix.

Cautiousness

Be sure if the name calling of your entity classes (or their properties) are also reserved SQL keywords like GROUP operating theatre USER. For example, if your entity's class name is Group, past, past default, the proportionate table nominate would be grouping. This bequeath cause an SQL error in some database engines. See Doctrine's Reserved SQL keywords support for details on how to properly break loose these names. Alternatively, if you're free to choose your database schema, simply map to a diverse table name surgery column name. See Doctrine's Creating Classes for the Database and Property Mapping software documentation.

Note

When using other library or program (e.g. Doxygen) that uses annotations, you should place the @IgnoreAnnotation annotation on the class to indicate which annotations Symfony should ignore.

For example, to prevent the @fn annotation from throwing an exception, add the favorable:

Fee

Later on creating your entities you should validate the mappings with the following command:

Generating Getters and Setters

Even though School of thought now knows how to persist a Mathematical product object to the database, the class itself isn't rattling useful thus far. Since Product is just a regular PHP separate with head-to-head properties, you penury to create public getter and setter methods (e.g. getName(), setName($advert)) in order to access its properties in the rest of your application program's code. Add these methods manually Beaver State with your own IDE.

Creating the Database Tables/Scheme

You now have a usable Intersection class with mapping information so that Doctrine knows exactly how to stay it. Of course, you wear't yet take over the corresponding product set back in your database. Fortunately, Doctrine can automatically create all the database tables needed for every known entity in your diligence. To do this, run:

Tip

Really, this command is incredibly powerful. IT compares what your database should look the like (supported the mapping information of your entities) with how it really looks, and executes the SQL statements requisite to update the database schema to where it should be. In other words, if you ADD a new attribute with map metadata to Product and run this command, it volition fulfil the "ALTER Hold over" statement needed to add that new column to the existing merchandise table.

An straight-grained better means to trespass of this functionality is via migrations, which allow you to generate these SQL statements and computer memory them in migration classes that can cost run systematically on your production waiter in order to update and track changes to your database schema safely and reliably.

Whether Beaver State not you take vantage of migrations, the doctrine:schema:update command should only be used during development. Information technology should not be used in a production surroundings.

Your database now has a fully-working product table with columns that gibe the metadata you've specific.

Persisting Objects to the Database

Now that you have mapped the Product entity to its similar product table, you're ready to persist Product objects to the database. From inside a controller, this is pretty easy. Add the chase method to the DefaultController of the bundle:

Billet

If you're following along with this example, you'll demand to create a route that points to this action mechanism to see it ferment.

Tip

This article shows working with Doctrine from within a controller by using the getDoctrine() method acting of the comptroller. This method is a shortcut to get the doctrine service. You can work with Philosophy anywhere else by injecting that serve in the Service. See Service Container for more on creating your have services.

Have a look at the previous example in more detail:

• lines 10-13 In this section, you instantiate and oeuvre with the $product object the like any other normal PHP targe.
• tune 15 This line fetches Doctrine's entity handler object, which is causative the process of persisting objects to, and fetching objects from, the database.
• line 18 The persist($product) call tells Philosophy to "manage" the $product object. This does non cause a query to be ready-made to the database.
• line 21 When the flush() method is called, Doctrine looks through all of the objects that information technology's managing to see if they indigence to be persisted to the database. In this example, the $product object's data doesn't be in the database, and so the entity manager executes an INSERT query, creating a new row in the ware table.

Mention

In fact, since Doctrine is aware of all your managed entities, when you call the flush() method, information technology calculates an overall changeset and executes the queries in the correct order. IT utilizes cached prepared statement to slenderly amend the carrying into action. For instance, if you persist a total of 100 Product objects and and then subsequently call flush(), School of thought wish execute 100 INSERT queries using a single prepared affirmation object.

Whether creating or updating objects, the workflow is e'er the same. In the succeeding section, you'll see how Doctrine is smart enough to automatically issue an UPDATE query if the entity already exists in the database.

Tip

Doctrine provides a library that allows you to programmatically load testing data into your undertaking (i.e. "fixture data"). For information, reckon the "`DoctrineFixturesBundle`_" documentation.

Fetching Objects from the Database

Fetching an objective back come out of the closet of the database is yet easier. For example, suppose you've configured a route to display a specific Ware based on its id respect:

When you query for a particular type of targe, you always apply what's known as its "repository". You can think of a repository as a PHP class whose only caper is to help you fetch entities of a certain class. You can access the deposit object for an entity class via:

Mention

You can as wel use AppBundle:Cartesian product sentence structure. This string is a shortcut you can utilisation anywhere in Doctrine instead of the whole class name of the entity (i.e. AppBundle\Entity\Product). As long American Samoa your entity lives under the Entity namespace of your roll up, this will work.

Formerly you bear a repository object, you can access all sorts of helpful methods:

You can also take reward of the useful findBy() and findOneBy() methods to easily fetch objects based on threefold conditions:

Tip

When version a page requires to pee-pee some database calls, the web debug toolbar at the bottom of the page displays the number of queries and the time it took to do them:

If the number of database queries is too high, the icon will turn yellow to signal that something may non follow correct. Click on the picture to open the Symfony Profiler and find out the exact queries that were executed.

Updating an Object

Once you've fetched an object from Doctrine, updating it is easy. Suppose you feature a route that maps a product id to an update action in a restrainer:

Updating an object involves just triplet steps:

1. fetching the object from School of thought;
2. modifying the object;
3. vocation flush() on the entity manager.

Notice that calling $entityManager->persist($product) isn't necessary. Hark back that this method bu tells Doctrine to manage or "scout" the $product object. In that case, since you fetched the $product object from Doctrine, it's already managed.

Deleting an Object

Deleting an object is selfsame similar, but requires a call to the remove() method acting of the entity manager:

As you might anticipate, the remove() method notifies Ism that you'd look-alike to remove the given targe from the database. The actual DELETE query, withal, International Relations and Security Network't actually executed until the flush() method is called.

Querying for Objects

You've already seen how the depository object allows you to run elemental queries without some work:

Of course of action, Doctrine also allows you to write more complex queries using the Philosophy Query Terminology (DQL). DQL is related to SQL except that you should imagine that you're querying for one or more objects of an entity class (e.g. Product) alternatively of querying for rows on a table (e.g. product).

When querying in Philosophical system, you have cardinal main options: writing pure DQL queries Oregon using Doctrine's Enquiry Detergent builder.

Querying for Objects with DQL

Imagine that you want to inquiry for products that price more than 19.99, consecutive from least to most big-ticket. You can use DQL, Philosophical system's native SQL-like language, to construct a query for this scenario:

If you're comfortable with SQL, then DQL should feel same natural. The biggest deviation is that you need to think in terms of selecting PHP objects, instead of rows in a database. For this reason, you select from the AppBundle:Product entity (an optional shortcut for the AppBundle\Entity\Production class) and then alias it as p.

Hint

Note of the setParameter() method. When working with Doctrine, IT's always a good idea to set any external values Eastern Samoa "placeholders" (:price in the exercise above) arsenic information technology prevents SQL injection attacks.

The getResult() method acting returns an raiment of results. To get only nonpareil result, you can utilize getOneOrNullResult():

The DQL syntax is incredibly powerful, allowing you to easily join between entities (the subject of relations will live covered subsequently), group, etc. For more information, see the official Doctrine Query Linguistic communication documentation.

Querying for Objects Using Doctrine's Query Builder

Rather of writing a DQL train, you can use a helpful object called the QueryBuilder to build that string for you. This is useful when the current query depends on dynamic conditions, as your code soon becomes hard to read with DQL as you start to concatenate strings:

The QueryBuilder object contains all method necessary to build your query. By career the getQuery() method, the query constructor returns a median Query object, which prat glucinium used to get down the result of the inquiry.

For much information on Doctrine's Question Builder, consult Doctrine's Query Builder documentation.

Organizing Custom Queries into Repository Classes

All the queries in the former sections were written directly in your controller. But for organization, Doctrine provides special depositary classes that allow you to keep all your interrogation logic in one, central place.

see How to Make custom Repository Classes for info.

Configuration

Doctrine is extremely configurable, though you probably won't ever indigence to worry roughly most of its options. To find outgoing more about configuring Doctrine, see the Doctrine section of the config credit.

Doctrine Discipline Types Reference

Doctrine comes with many field types available. Each of these maps a PHP data character to a specific column type in whatever database you're using. For each field type, the Newspaper column can exist configured advance, setting the length, nullable behavior, public figure and other options. To see a list of all available types and more information, see Doctrine's Mapping Types documentation.

Final Thoughts

With Doctrine, you can focus on your objects and how they'Ra used in your application and occupy about database tenaciousness second. This is because Doctrine allows you to use any PHP object to hold your data and relies on mapping metadata information to map an object's data to a particular database table.

Philosophical system has a lot more complex features to larn, the like relationships, complex queries, and event listeners.

How to Write Sql Query in Doctrine Where to Check Two Values Are Equal or Not

Source: https://symfony.com/doc/2.7/doctrine.html

Share this post