combining data in several rows

I have a table with 开发者_如何学Pythonthe same participant (person_id) attached to a variable amount of rows of data. I need to return the different data for the same column no matter how many times this person entered the data and do this for over 20,000 entrants in one report.

Any suggestions?

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You asked the question later too? and not giving more info here: Combining Records in a query