It seems that the symfony generator needs a primary key. If there’s no PK defined the generator throws the following exception:

symfony generator Invalid column name ‘id’

In some blog post they solved the problem by adding a primary key to the concerning table. But in my case the DB isn’t under my control, so I found out that it is enough to set the primary key only in the schema.

For instance:

my_table:
  connection: doctrine
  tableName: MyTable
  columns:
    id:
      type: int(11)
      primary: true  # <-- SET TO true