CODEWITHSUNDEEP
pythonmysqlsqlalchemy
Peter McG
Peter McG

Reputation: 19035

Reverse engineer SQLAlchemy declarative class definition from existing MySQL database?

I have a pre-existing mysql database containing around 50 tables.

Rather than hand code a declarative style SqlAlchemy class (as shown here) for each table, is there a tool/script/command I can run against the mysql database that will generate a python class in the declarative style for each table in the database?

To take just one table as an example (would generate for all 50 ideally) as follows:

+---------+--------------------+
| dept_no | dept_name          |
+---------+--------------------+
| d009    | Customer Service   |
| d005    | Development        |
| d002    | Finance            |
| d003    | Human Resources    |
| d001    | Marketing          |
| d004    | Production         |
| d006    | Quality Management |
| d008    | Research           |
| d007    | Sales              |
+---------+--------------------+

Is there a tool/script/command that can generate a text file containing something like:

from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

class Department(Base):
   __tablename__ = 'departments'

   dept_no = Column(String(5), primary_key=True)
   dept_name = Column(String(50))

   def __init__(self, dept_no, dept_name):
       self.dept_no = dept_no
       self.dept_name = dept_name

   def __repr__(self):
      return "<Department('%s','%s')>" % (self.dept_no, self.dept_name)

Upvotes: 25

Views: 10072

Answers (4)

nosklo
nosklo

Reputation: 222852

use sqlautocode:

It is a flexible tool to autogenerate a model from an existing database.

This is a slightly different approach to SqlSoup, which lets you use tables without explicitly defining them. On the other hand, sqlalutocode will generate actual python code.

Upvotes: 31

Bill Karwin
Bill Karwin

Reputation: 562270

SqlSoup can perform introspective mapping of an existing SQL schema.

Upvotes: 5

Johannes Fahrenkrug
Johannes Fahrenkrug

Reputation: 44730

Now (in 2015) you probably would want to use https://pypi.python.org/pypi/sqlacodegen instead!

Upvotes: 12

zzzeek
zzzeek

Reputation: 75127

Keep in mind declarative can be used with reflected tables. So if startup time weren't a huge issue you could do this:

engine = create_engine('mysql://...')
meta = MetaData()
meta.reflect(bind=engine)
for table in meta.tables.values():
    print """
class %s(Base):
    __table__ = Table(%r, Base.metadata, autoload=True)

""" % (table.name, table.name)

other than that autocode is probably the way to go.

Upvotes: 8

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