I would like to do a conditional insert of a a single row. This is often
useful in a CRUD app for checking permissions and inserting in a single
database call:
INSERT INTO project (name, user_id)
SELECT :name, :user_id
WHERE EXISTS (
SELECT 1
FROM users
WHERE id = :user_id
Hello Simon,
I tried your suggestion as POC:
def setup_event_handlers(engine):
@event.listens_for(engine, 'do_connect')
def receive_do_connect(dialect, conn_rec, cargs, cparams):
print("inside do_connect")
print('password %s' % cparams['password'])
try:
print("inside try")
return
I don't know anything about Airflow. Are you sure that each of these
tasks is running inside the same Python interpreter/process? I see
Airflow can distribute tasks among workers:
https://airflow.apache.org/docs/apache-airflow/stable/executor/index.html
This sounds like a problem that is going
for one engine with 18 databases, what is "switching the bindings" ? do you
mean you call "USE " on the connection ?
creating 18 separate engines would not be that big a deal if that's what works
best for the code, no issue doing that.
On Tue, Mar 22, 2022, at 9:41 AM, Mustafa Demiraslan
Current structure is like this:
[image: image.png]
I can't manage pooling for green colored databases.
Mike Bayer , 22 Mar 2022 Sal, 17:12 tarihinde
şunu yazdı:
> for one engine with 18 databases, what is "switching the bindings" ? do
> you mean you call "USE " on the connection ?
>
>
Hi team,
I am using 3 database engines at the same time, 1(include 1 database) +
1(include 1 database) + 1(include 18 database). I use the database
containing 18 databases by switching the bindings. I connect to database
using sessions with session_maker for each engine. During the load test, I
a single Engine only points to one database URL at a time. so to that extent,
as an Engine assumes there's a "default database" when it connects, any concept
of multiple "databases" beneath that is not something the Engine is aware of.
PostgreSQL itself has no "USE" command, so if you have
Yes all of these are a database not schema.
Thank you for response.
Mike Bayer , 22 Mar 2022 Sal, 18:27 tarihinde
şunu yazdı:
> a single Engine only points to one database URL at a time. so to that
> extent, as an Engine assumes there's a "default database" when it connects,
> any concept of
