SQLAlchemy printing raw SQL from create()

Question

I am giving Pylons a try with SQLAlchemy, and I love it, there is just one thing, is it possible to print out the raw SQL CREATE TABLE data generated from

Answer 1

It turns out this is straight-forward:

from sqlalchemy.dialects import postgresql
from sqlalchemy.schema import CreateTable
from sqlalchemy import Table, Column, String, MetaData

metadata = MetaData()

users = Table('users', metadata,
              Column('username', String)
)

statement = CreateTable(users)

print(statement.compile(dialect=postgresql.dialect()))

Outputs this:

CREATE TABLE users (
    username VARCHAR
)

Going further, it can even support bound parameters in prepared statements.

Reference

How do I render SQL expressions as strings, possibly with bound parameters inlined?

...

or without an Engine:

from sqlalchemy.dialects import postgresql
print(statement.compile(dialect=postgresql.dialect()))

SOURCE: http://docs.sqlalchemy.org/en/latest/faq/sqlexpressions.html#faq-sql-expression-string

Example: Using SQL Alchemy to generate a user rename script

#!/usr/bin/env python
import csv
from sqlalchemy.dialects import postgresql
from sqlalchemy import bindparam, Table, Column, String, MetaData

metadata = MetaData()

users = Table('users', metadata,
              Column('username', String)
)

renames = []

with open('users.csv') as csvfile:
    for row in csv.DictReader(csvfile):
        renames.append({
            'from': row['sAMAccountName'],
            'to': row['mail']
        })

for rename in renames:
    stmt = (users.update()
            .where(users.c.username == rename['from'])
            .values(username=rename['to']))
    print(str(stmt.compile(dialect=postgresql.dialect(),
                           compile_kwargs={"literal_binds": True})) + ';')

When processing this users.csv:

sAMAccountName,mail
bmcboatface,boaty.mcboatface@example.com
ndhyani,naina.dhyani@contoso.com

Gives output like this:

UPDATE users SET username='boaty.mcboatface@example.com' WHERE users.username = 'bmcboatface';
UPDATE users SET username='naina.dhyani@contoso.com' WHERE users.username = 'ndhyani';users.username = 'ndhyani';

Why a research vessel has an email address is yet to be determined. I have been in touch with Example Inc's IT team and have had no response.