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Rename automatically named foreign keys with Alembic
Gergely Polonkai
Jan 2, 2017 :: 10:41

I have recently messed up my Alembic migrations while modifying my SQLAlchemy models. To start with, I didn’t update the auto-generated migration files to name the indexes/foreign keys a name, so Alembic used its own naming scheme. This is not an actual problem until you have to modify columns that have such constraints. I have since fixed this problem, but first I had to find which column references what (I had no indexes other than primary key back then, so I could go with foreign keys only). Here is a query I put together, mostly using this article.

Haversine in MySQL
Gergely Polonkai
Mar 5, 2013 :: 13:49

Just insert it in your database, feed them two Google coordinates, and you get the distance in kilometres. If you happen to need it in miles, change the constant 12756.200 in the RETURN row to 7922.6 instead.

Gergely Polonkai is a systems engineer of a telco company, and also a freelancer self- and software developer.

He is learning about different IT subjects since the late 1990s. These include web development, application building, systems engineering, IT security and many others. He also dug his nose deeply into free software, dealing with different types of Linux and its applications, while also writing and contributing to some open source projects.

On this site he is writing posts about different stuff he faces during work (oh my, yet another IT solutions blog), hoping they can help others with their job, or just to get along with their brand new netbook that shipped with Linux.

“I believe one can only achieve success if they follow their own instincts and listen to, but not bend under others’ opinions. If you change your course just because someone says so, you are following their instincts, not yours.”