Solving m2m Joins via Composite keys

Solving m2m Joins via Composite keys

Creating composite keys in order to link tables via one-to-many relationships

When to use

Use when you need to consolidate two (or more) columns in order to create a column that can be used to create one-to-many joins

Instructions

An example of this type of relationship is where Account and Dept are in separate columns, but the account number shows up in multiple departments.  To create a composite column:

• Edit your query
• Select the 2 columns (the primary column first)
• Go to Add Column > Merge
• Choose to use a separator
• Rename the column

Hints & tips

• This technique can work well on its own, but may also require table de-aggregation as well (covered in the section on Solving m:m joins via De-Aggregation)