after the join tool, some lines(records) are duplicated!!

[ueni]

left data set has 96 records, right data set has 178 records - used join tool to join by specific fields and the final output came out with some duplicate lines, was expecting 96 records from left data set with new additional fields as result of join but duplicate records have been generated! what it could be .. been using join on other occasions and it worked well but no idea what's the gap here? can you please help

[Qiu]

@ueni 
You can check the Left anchor of the Join too, what is the data stream that could not be matched.
If you can upload some some sample data, we can take a look.

[ueni · Accepted solution]

worked with Tony, he advised to use 'Unique' tool before the join to get rid of duplicate rows and it worked!