howto create db mysql with sqlalchemy

Question

I need to create a db in mysql using sqlalchemy, I am able to connect to a db if it already exists, but I want to be able to create it if it does not exist. this are my tabl

Answer 1

I don't know what the canonical way is, but here's a way to check to see if a database exists by checking against the list of databases, and to create it if it doesn't exist.

from sqlalchemy import create_engine

# This engine just used to query for list of databases
mysql_engine = create_engine('mysql://{0}:{1}@{2}:{3}'.format(user, pass, host, port))

# Query for existing databases
existing_databases = mysql_engine.execute("SHOW DATABASES;")
# Results are a list of single item tuples, so unpack each tuple
existing_databases = [d[0] for d in existing_databases]

# Create database if not exists
if database not in existing_databases:
    mysql_engine.execute("CREATE DATABASE {0}".format(database))
    print("Created database {0}".format(database))

# Go ahead and use this engine
db_engine = create_engine('mysql://{0}:{1}@{2}:{3}/{4}'.format(user, pass, host, port, db))

Here's an alternative method if you don't need to know if the database was created or not.

from sqlalchemy import create_engine

# This engine just used to query for list of databases
mysql_engine = create_engine('mysql://{0}:{1}@{2}:{3}'.format(user, pass, host, port))

# Query for existing databases
mysql_engine.execute("CREATE DATABASE IF NOT EXISTS {0} ".format(database))

# Go ahead and use this engine
db_engine = create_engine('mysql://{0}:{1}@{2}:{3}/{4}'.format(user, pass, host, port, db))

Answer 2

You can use SQLAlchemy-Utils for that.

pip install sqlalchemy-utils

Then you can do things like

from sqlalchemy_utils import create_database, database_exists
url = 'mysql://{0}:{1}@{2}:{3}'.format(user, pass, host, port)
if not database_exists(url):
    create_database(url)

I found the answer here, it helped me a lot.

Answer 3

CREATE DATABASE IF NOT EXISTS dbName;

Answer 4

To create a mysql database you just connect to the server an create the database:

import sqlalchemy
engine = sqlalchemy.create_engine('mysql://user:password@server') # connect to server
engine.execute("CREATE DATABASE dbname") #create db
engine.execute("USE dbname") # select new db
# use the new db
# continue with your work...

of course your user has to have the permission to create databases.