title: insert null value using doctrine fixtures (symfony)
body: <p>my question is very simple. I have this model where i want to insert a record with a null value in one of the fields (<code>finRango</code>), using the data fixtures of doctrine orm. here's what ive tried:</p>
  
  <pre><code>  fila41_zona5:
      MetodoEnvio: dhl
      zona: 5
      inicioRango: 20.00
      finRango: NULL
      precio: 7.15
  </code></pre>
  
  <p>also tried:</p>
  
  <pre><code>  fila41_zona5:
      MetodoEnvio: dhl
      zona: 5
      inicioRango: 20.00
      finRango: 
      precio: 7.15
  </code></pre>
  
  <p>and even:</p>
  
  <pre><code>  fila41_zona5:
      MetodoEnvio: dhl
      zona: 5
      inicioRango: 20.00
      precio: 7.15
  </code></pre>
  
  <p>I keep always getting a zero (0.00) in the <code>finRango</code> field. I defined my schema from the database schema, and this field is not defined with <code>NOT NULL</code>. It is part of the primary key of the table, but it can be <code>NULL</code> (I need it to be null in a particular case, because of what the model represents). Here's the schema definition generated by the task <code>php symfony doctrine:build-schema</code>:</p>
  
  <pre><code>//An extract from my config/doctrine/schema.yml:
  PrecioEnvio:
    connection: doctrine
    tableName: PrecioEnvio
    columns:
      idmetodo:
        type: integer(4)
        fixed: false
        unsigned: true
        primary: true
        autoincrement: false
      zona:
        type: integer(4)
        fixed: false
        unsigned: false
        primary: true
        autoincrement: false
      iniciorango:
        type: 'decimal(10, 2)'
        fixed: false
        unsigned: false
        primary: true
        autoincrement: false
      finrango:
        type: 'decimal(10, 2)'
        fixed: false
        unsigned: false
        primary: true
        autoincrement: false
      precio:
        type: 'decimal(10, 2)'
        fixed: false
        unsigned: false
        primary: false
        notnull: true
        autoincrement: false
    relations:
      MetodoEnvio:
        local: idmetodo
        foreign: id
        type: one
  </code></pre>
  
  <p>This is the SQL definition of the table, from which this schema was generated:</p>
  
  <pre><code>CREATE  TABLE IF NOT EXISTS `sawpruebaTienda`.`PrecioEnvio` (
    `idMetodo` INT UNSIGNED NOT NULL ,
    `zona` INT(3) NOT NULL ,
    `inicioRango` DECIMAL(10,2) NOT NULL COMMENT 'Marca el inicio del rango de peso para el cual este precio aplica.' ,
    `finRango` DECIMAL(10,2) NULL COMMENT 'Marca el fin del rango de peso para el cual este precio aplica.' ,
    `precio` DECIMAL(10,2) NOT NULL ,
    PRIMARY KEY (`idMetodo`, `inicioRango`, `finRango`, `zona`) ,
    INDEX `fk_PrecioEnvio_MetodoEnvio` (`idMetodo` ASC) ,
    CONSTRAINT `fk_PrecioEnvio_MetodoEnvio`
      FOREIGN KEY (`idMetodo` )
      REFERENCES `sawpruebaTienda`.`MetodoEnvio` (`id` )
      ON DELETE NO ACTION
      ON UPDATE NO ACTION)
  ENGINE = InnoDB
  DEFAULT CHARACTER SET = utf8
  COLLATE = utf8_general_ci;
  </code></pre>
  
  <p>Even being uncapitalized in the schema, the fields <code>inicioRango</code> and <code>finRango</code> are interpreted properly. The only problem is when i try to store the <code>NULL</code> value on <code>finRango</code>.</p>
  
  <p>I'm using MySQL!</p>
  
  <p>Thanks for any help!</p>