How can you create a relationship between two Data Extensions?

if you want to combine or join two data extension together, you can relate them in the selected data sources section of your selection these relations are created by dragging one data extension on top of another in the selected data sources section, and defining how they are connected choose the field in the first data extension that matches the field in the second data extension usually, this will be an id or email address field in deselect segment, we call these the matching columns choose an option in the dropdown in the middle below is a list of the available options for how the data extensions should relate to each other in deselect segment, we call these the matching types in sql, these are the joins true 165,165,165,166left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type left unhandled content type