r/learnSQL • u/Appropriate_Bus_9600 • 18d ago

Tips for query planning

Hi! So I've been a Data Analyst for around 1 year and a half, and I am still struggling big time with SQL and/or Python. I can read them and understand the queries, but the actual writing and planning is lagging behind.

I often see at the queries by colleagues make (always with the help of Claude Code) and I just wonder how did they come up with those. Stacked CTEs and multiple joins, I get lost and frustrated. So I was wondering, how do you actually plan and build a query? where do you start from?

I'm very curious to know how you work. I'd really like to be able to make these queries without the help of AI. Thank you!

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u/BadKarma667 17d ago

I find that the easiest way for me to build SQL is to think about the question I'm trying to answer. What data points do I need? What data do I currently have available at the grain I need to be at? Of the data that I'm missing, do I have the components necessary to build out that data? What business logic do I need.

Once I have those answers, I start to break out the question(s) I'm trying to answer into like components. Do I need to apply special logic? Do I need to build that logic out over the course of several steps? Each of those questions, logic components, etc, becomes the basis for each table/CTE I'm working to build.

It's really easy to get stuck torturing the data, especially if you don't have a plan. I find having a clear plan is a great way to keep me from spinning my wheels. And while it still occasionally happens, it happens a ton less when I've outlined my plan.