doctrine 2

Accessing SQL parameters and its values in DQL 2 in Symfony 2

Hi All,

When you are executing a DQL there must be situation where you might need to see the parameters and its values for the underlying SQL. Usually Doctrine queries are prepared statements and you will not be able to see the values which pass through the query. Prepared statement works in the following way,

  1. Sending the statement,
  2. Sending the parameters,
  3. And executing the prepared statement.
    (More information on prepared statements :- http://www.w3schools.com/pHp/php_mysql_prepared_statements.asp)

So, what you see when you get the SQL query is something similar to this,

 SELECT * FROM some_table WHERE column1 = ? AND column2 = ?

So today, I am going to show you a workaround to get the parameters (such as column1, column2 and so on…) and most importantly get the respective values for those parameters. Continue reading →

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Thoughts on data persist in Symfony 2

Hi All,

Today I will be discussing about persisting form submitted data in Symfony 2. Data persisting is all about inserting/updating records to/in a table in database. In this example I assume that you have a form ready which will contain few fields in order to insert values to the database. This is exactly what I am going to do in the following scenario. I will have a table (Entity) called ‘user_details (UserDetails)’. I will be passing some values from a form (which is not here) to the ‘insertUserDetails‘ action in ‘UserDetails‘ controller. Then using that action, I will be inserting new user details to the ‘user_details‘ table.

Well, in this post I would like to have an open ended discussion regarding data persisting. The approach you are using can be different from mine but still do the same intended job. More or less performance can vary, lines of codes can vary, efficiency can vary and so on.  You can see the controller and function below. First take a look at the code and I will explain the code below. Continue reading →

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SQL into DQL, examples | Symfony 2 | Doctrine 2

Hi everyone,

Today I am going to talk about some examples on converting SQL queries into DQL . Doctrine query language (DQL) is the query language used by Doctrine ORM. Doctrine ORM 2.x is shipped with Symfony 2.x by default. Let’s take some examples and discuss. For the following examples we will be creating an instance of Doctrine query builder to structure DQL’s. 

Creating an instance of doctrine query builder

$em = $this->getDoctrine()->getManager();

$result = $em->createQueryBuilder();

SQL

SELECT * FROM contact

DQL

$dql = $result->select(‘c’)
->from(‘ACMETestBundle:Contact’, ‘c’)
->getQuery();

Continue reading →

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Many-to-one relationship mapping using Doctrine 2 in Symfony 2 in YAML

Hello doctrine lovers,

Well come back. In my previous post, we discussed how to map one-to-one relationships. If you have not read it but want to make yourself aware of one-to-one relationship mapping in Doctrine using YAML, make sure you read it before reading this post. So, today I am going to show you how to map many-to-one relationships in both unidirectional and bidirectional ways using Doctrine 2. As you are aware by now I will be using YAML instead of PHP annotations or XML. It is simply because YAML is very easy to understand (though you need to stick with proper indentation, which is not a big deal), will not run into unexpected problems, such as pre-compilers/caching engines tend to ignore comments, which will be used in annotations and few other things. By the way, in Symfony 2, you can use either YAML, Annotations or XML as part of the Doctrine configuration, but use one, not all. Symfony 2 evaluates all these methods equally. At the end of this post, you will learn a technique to evaluate your mapping whether it’s correct or not. So make sure you don’t miss anything in this post.

So back to the topic. Let’s have a quick look at what’s many-to-one relationship is all about. In simple terms, many-to-one is many rows of a table can be relate with only one row of another table. Take a look at the image below,

many-to-one-relationship

So basically, what this tells is, one supplier can have more than one product. For an in instance supplier ‘acer’ can have more than one products such as aspire e1 series laptops, e2 series laptops and so on.

Unidirectional – Many to One

In Unidirectional many-to-one mapping, you will only point to the target table from the parent table (same as in the one-to-one example in my previous post). I call ‘product‘ table as the owning side (parent table) and ‘supplier‘ table as the target table. The reason why I declare parent table to be the owning side is below, Continue reading →

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One-to-one relationship mapping using Doctrine 2 in Symfony 2 in YAML

Hi doctrine 2 lovers,

As I promised in my previous post, here I came with my very next post, which is the relationship mapping using Doctrine 2. Before going any further make sure that you have read my previous post, which is about table mapping using Doctrine 2.  And I assume you have at least a little bit of knowledge about using Doctrine 2 YAML syntaxes and indentation, which is also highlighted in my previous post.  Ok, enough about my previous post, now let’s get back to the today’s topic 🙂

As you know, or will know in a moment, there are two major types of relationships between tables. Which are,

  1. Unidirectional
  2. Bidirectional

And with above two types, the relationship could be,

  1. One-To-One
  2. One-To-Many
  3. Many-To-One
  4. Many-To-Many

In this post I will be discussing on all eight combinations starting on Unidirectional/Bidirectional relationship types of one-to-one.

Continue reading →

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