yogi_merge data from incomplete list into complete list

Google Spreadsheet   Post  #2571

Yogi Anand, D.Eng, P.E.      ANAND Enterprises LLC -- Rochester Hills MI     Jan-08-2019

question by: MLDHelp:
https://productforums.google.com/forum/?utm_medium=email&utm_source=best_answer_notification_button#!topic/docs/-T3GAl9u0wg;context-place=mydiscussions
How to merge data from incomplete list into complete list?
I want to copy information from an incomplete data set from one sheet into another sheet with a complete set. 

In the complete set sheet, column A has each state (AL, AK, AR, etc) and column B has the district number (1, 2, 3, ...). This sheet has every state and every district included. 

In the incomplete set sheet, column A has each state (AL, AK, AR, etc) and column B has district number (1,2,3,...). Column C has the number of funded projects and column D has the amount of funding that district received from the federal government. BUT, districts that didn't get any money aren't listed. 

So how can I copy column C and D from the incomplete set sheet to the complete set sheet and leave the missing districts blank (or better yet, make them 0)?

Thanks.