Group by ACCOUNT, then by date, process each group in turn, get the interval from first group from to the current group, and perform deduplication and counting. But SQL grouping must be accompanied by ...

My table is as follows: I have a candidate key using columns A-E. This is too many, but column A is very helpful to keep in each table that references it, so I want to generate a surrogate key using ...

📦 SQL analysis of fast delivery agent reviews using MySQL. 🔍 Covers DISTINCT, WHERE, ORDER BY, NULL, UPDATE & views. 📊 Business insights + optimized queries. 🎯 Includes SQL interview Q&A. 🚀 Task ...