how to set autocommit = 1 in a sqlalchemy.engine.Connection

问题

In sqlalchemy, I make the connection:

 conn = engine.connect()

I found this will set autocommit = 0 in my mysqld log. Now I want to set autocommit = 1 because I do not want to query in a transaction.

Is there a way to do this?

回答1:

From The SQLAlchemy documentation: Understanding autocommit

conn = engine.connect()
conn.execute("INSERT INTO users VALUES (1, 'john')")  # autocommits

The “autocommit” feature is only in effect when no Transaction has otherwise been declared. This means the feature is not generally used with the ORM, as the Session object by default always maintains an ongoing Transaction.

Full control of the “autocommit” behavior is available using the generative Connection.execution_options() method provided on Connection, Engine, Executable, using the “autocommit” flag which will turn on or off the autocommit for the selected scope. For example, a text() construct representing a stored procedure that commits might use it so that a SELECT statement will issue a COMMIT:

engine.execute(text("SELECT my_mutating_procedure()").execution_options(autocommit=True))

回答2:

What is your dialect for mysql connection?

You can set the autocommit to True to solve the problem, like this mysql+mysqldb://user:password@host:port/db?charset=foo&autocommit=true

回答3:

You can use this:

from sqlalchemy.sql import text

engine = create_engine(host, user, password, dbname)
engine.execute(text(sql).execution_options(autocommit=True))

回答4:

In case you're configuring sqlalchemy for a python application using flask / django, you can create the engine like this:

# Configure the SqlAlchemy part of the app instance
app.config['SQLALCHEMY_DATABASE_URI'] = conn_url


session_options = {
    'autocommit': True
}

# Create the SqlAlchemy db instance
db = SQLAlchemy(app, session_options=session_options)

回答5:

This can be done using the autocommit option in the execution_option() method:

engine.execute("UPDATE table SET field1 = 'test'").execution_options(autocommit=True))

This information is available within the documentation on Autocommit

来源：https://stackoverflow.com/questions/26717790/how-to-set-autocommit-1-in-a-sqlalchemy-engine-connection

标签

python

sqlalchemy