Tags / unpivot
Using SQL and UNION ALL to Aggregate Data from Multiple Columns
How to Create a Pivot Table in Oracle SQL Without Using Aggregate Functions
Transforming a Table with Column Names as Values for Phone Numbers
Pivot Table Aggregation - Converting Rows to Columns by Date
Unpivoting Columns with SQL: A Step-by-Step Guide to Transforming Complex Data Formats
5 Effective Ways to Sum Dates in PostgreSQL Using Lateral Join