Tags / outer-join
How to Avoid Duplicate Rows with Left Outer Join and Group By Clause in SQL Server
Fetching Uncommon Data from Oracle SQL: A Guide to Using the MINUS Operator
Left Joining Twice on the Same Table with Multiple IDs Using SQL and Common Table Expressions (CTEs)
Combining Data Rows from Multiple Tables Without Repeating Row IDs Using SQL Joins and Conditional Aggregation