Automatically generate / reverse engineer a MySQL database and generate Scala JPA classes for tables

mysql_to_jpa.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

from sqlalchemy import create_engine
from sqlalchemy.engine import reflection
from datetime import datetime

engine = create_engine('mysql://username:@localhost/foobar')
insp = reflection.Inspector.from_engine(engine)

def scala_table_name(table_name):
	if table_name.endswith('_t'): return table_name[:-2]
	else: return table_name

def scala_column_name(column_name):
	if column_name == 'type_f': return '`type`'
	elif column_name.endswith('_f'): return column_name[:-2]
	else: return column_name

def scala_type(python_type):
	if python_type == str: return "String"
	elif python_type == int: return "java.lang.Long" # Scala "Long" isn't nullable by JPA
	elif python_type == datetime: return "java.util.Calendar"
	else: raise "Bad Type"

BAD_COLUMNS = ('id_f', 'ts', 'host', 'vers', 'archived')

COLUMN_TEMPLATE = """
  @javax.persistence.Column(name="%(name)s") @scala.reflect.BeanProperty var %(scala_name)s : %(type)s = _
"""[1:-1]

CLASS_TEMPLATE = """
@javax.persistence.Entity(name="%s")
class %s extends FooBarTable {
"""[:-1]

for table_name in insp.get_table_names():
    print CLASS_TEMPLATE % (table_name, scala_table_name(table_name))
    for column in insp.get_columns(table_name):
        if column['name'] in BAD_COLUMNS: continue
        print COLUMN_TEMPLATE % \
          { 'name': column['name'],
            'scala_name' : scala_column_name(column['name']),
            'type' : scala_type(column['type'].python_type) }
    print "}"