I have created a model and executed syncdb which had created the tables as my model was designed.
Afterwards I modified the model and executed makemigrations which created the migrations ignoring the tables that syncdb had already created.
So I ended up with an error "relation already exists".
Why did makemigrations created everything from scratch? How do I fix this situation ?
makemigrations creates new migrations based on the changes detected to your models.
Also, one thing to note is syncdb command is deprecated since Django 1.7 and will be removed in Django 1.9. So, you should use the migrate command.
From syncdb docs:
Deprecated since version 1.7:
This command has been deprecated in favor of themigratecommand, which performs both the old behavior as well as executing migrations.