Scenario 3 - Left Join

Going to look at left joins because it is by far the most common type of join, but the same techniques and problems can exist for inner and outer joins also.

"it_support_tickets_2026.xlsx" contains IT help desk tickets
"employee_directory.csv" contains all of the employees, their names, offices, phone number, etc.

We can load them into EasyMorph by dragging-and-dropping them.

We can add the "Merge another table" action to the support tickets in Left Join mode to join the employee directory to it.
 
Looking a the table meta data, we can see before the join there were 1,200 records but after the join there are more. 

Many people think this increase isn't possible as a left join is like a lookup but for more fields, but it is possible when there are duplicates in either or both tables.

Use the merge profiler to see that there are duplicates in the employee directory table.

Add the "Deduplicate rows" action to the employee directory to remove them.

See that after the row count is correct and that the merge profiler shows no duplicate matches.