Freaks City

When building dashboards or analytics features, it's common to visualize metrics like daily user signups, page views, or logins over a date range. A key requirement is that the result must include every day in the interval, even if no activity occurred on that day—those antries should show a count of zero. Sample Schema Consider a user table wi ...

Problem Overview This problem involves calculating bonus coins earned from consecutive daily check-ins. The challenge lies in correctly identifying continuous check-in periods and applying bonus rules at specific intervals. Table Structure Table: tb_user_log Core Concepts Bonus Rules Base: 1 coin per day Every 3rd consecutive day: +2 bonus coi ...

Recursive Query Fundamentals Recursive queriees enable hierarchical data processing by referencing the query itself during execution. Starting from version 5.7, MySQL supports recursive queries through Common Table Expressions (CTE) with the WITH RECURSIVE clause. This capability is particularly useful for managing tree-structured data such as ...