I wouldn't recommend this unless it really fits your use case. For me I needed to report whether a set of users had completed various tasks. The tasks wouldn't be known ahead of time, but the report is always limited to a set of users who share the same set of tasks. This approach allowed me to build a report that works for different sets of users and the tasks don't need to be known ahead of time.
Big downside is that my query creates a bunch of dependent subqueries. Because the number of rows (users) and tasks (columns) in a given report is always within a reasonable number, it runs quickly. Your mileage may vary.
https://stackoverflow.com/questions/12004603/mysql-pivot-row...
I wouldn't recommend this unless it really fits your use case. For me I needed to report whether a set of users had completed various tasks. The tasks wouldn't be known ahead of time, but the report is always limited to a set of users who share the same set of tasks. This approach allowed me to build a report that works for different sets of users and the tasks don't need to be known ahead of time.
Big downside is that my query creates a bunch of dependent subqueries. Because the number of rows (users) and tasks (columns) in a given report is always within a reasonable number, it runs quickly. Your mileage may vary.