Tag archive

#conditional

Commands grouped around the same concept, pattern, or recurring problem.

6 commands with this tag Browse related patterns quickly

advanced aggregation MySQL MariaDB SQL Server PostgreSQL SQLite

Aggregate Rows Conditionally With CASE Inside An Aggregate

Use `CASE WHEN` inside `SUM` or `COUNT` to produce multiple metrics from a single pass over grouped data.

intermediate aggregation MySQL MariaDB SQL Server PostgreSQL SQLite

Count Users at Each Step of a Conversion Funnel

Measure how many unique users completed each stage of a multi-step flow using `COUNT(DISTINCT CASE WHEN event_name = '...' THEN user_id END)` per step.

beginner conditional-logic MySQL MariaDB SQL Server PostgreSQL SQLite

Replace NULL Values With COALESCE

Return the first non-null value from a list of expressions.

intermediate conditional-logic MySQL MariaDB SQL Server PostgreSQL SQLite

Return Different Values With CASE WHEN

Evaluate conditions row-by-row inside a `SELECT` to produce computed columns based on branching logic.

intermediate null-handling MySQL MariaDB SQL Server PostgreSQL SQLite

Return NULL When Two Values Are Equal With NULLIF

Use `NULLIF` to convert a specific value to `NULL`, most commonly to prevent division-by-zero errors.

intermediate updating MySQL MariaDB SQL Server PostgreSQL SQLite

Update a Column Based on Conditions With CASE WHEN

Set a column to different values depending on other column values in the same row by using `CASE WHEN` inside a `SET` clause.