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  • Showing only topics in ~comp with the tag "sql". Back to normal view / Search all groups
    1. What are your favorite Postgres features?

      You could use any SQL database to create a few tables, insert some data, and do queries, while ignoring anything vendor-specific. But Postgres has a lot of other features and many extensions. What...

      You could use any SQL database to create a few tables, insert some data, and do queries, while ignoring anything vendor-specific. But Postgres has a lot of other features and many extensions. What do you recommend checking out beyond the basics?

      I've used a lot of databases, but it's been many years, so I assume things have changed quite a bit. I skimmed a few PostgreSQL release notes and learned that there's now a MERGE statement that looks pretty handy. (It's standard SQL.) And from Neon's list of supported extensions, the plv8 extension caught my eye. It would let me write stored procedures in JavaScript. Does anyone use that? Do you use stored procedures at all?

      I wonder what Tildes uses?

      (To keep discussion organized, please write about one feature per top-level comment.)

      17 votes
    2. Dealing with databases, inserts, updates, etc. in Python

      Current Library: built in sqlite Current db: sqlite (but will have access to Snowflake soon for option 1 below) Wondering if anyone here has some advise or a good place to learn about dealing with...

      Current Library: built in sqlite
      Current db: sqlite (but will have access to Snowflake soon for option 1 below)

      Wondering if anyone here has some advise or a good place to learn about dealing with databases with Python. I know SQL fairly well for pulling data and simple updates, but running into potential performance issues the way I've been doing it. Here are 2 examples.

      1. Dealing with Pandas dataframes. I'm doing some reconciliation between a couple of different datasources. I do not have a primary key to work with. I have some very specific matching criteria to determine a match (5 columns specifically - customer, date, contract, product, quantity). The matching process is all built within Python. Is there a good way to do the database commits with updates/inserts en masse vs. line by line? I've looked into upsert (or inserts with clause to update with existing data), but pretty much all examples I've seen rely on primary keys (which I don't have since the data has 5 columns I'm matching on).

      2. Dealing with JSON files which have multiple layers of related data. My database is built in such a way that I have a table for header information, line level detail, then third level with specific references assigned to the line level detail. As with a lot of transactional type databases there can be multiple references per line, multiple lines per header. I'm currently looping through the JSON file starting with the header information to create the primary key, then going to the line level detail to create a primary key for the line, but also include the foreign key for the header and also with the reference data. Before inserting I'm doing a lookup to see if the data already exists and then updating if it does or inserting a new record if it doesn't. This works fine, but is slow taking several seconds for maybe 100 inserts in total. While not a big deal since it's for a low volume of sales. I'd rather learn best practice and do this properly with commits/transactions vs inserting an updating each record individually within the ability to rollback should an error occur.

      11 votes
    3. Recommendations to learn SQL?

      I read the AskReddit thread on "What costs less than $100 that changed your life?" (link unavailable since I'm at work) but someone responded "SQL" - jobs just open up that make a ton of money. I...

      I read the AskReddit thread on "What costs less than $100 that changed your life?" (link unavailable since I'm at work) but someone responded "SQL" - jobs just open up that make a ton of money.

      I did a cursory search on Indeed and holy moly they were right -- SQL jobs get easily 2x what I make now. I'm pretty good at Excel and that sort of thinking, so I was thinking I'd try taking a class.

      Do yall have any recommendations as to a good course to take in SQL, preferably online, preferably free or cheap? I'm willing to pay a bit if it'll mean I can make a lot more, but I'm currently not making a ton, haha.

      Any responses welcome, including ideas as to how to break into like, tech-oriented fields as well.

      9 votes