Import CSV Overwrite existing data

[Remon_Toma]

Hello, i hope someone can help in that.

when i use import csv function to update existing data, so it clear the data already exist if i did not include this column in the imported file. for example if i have four columns in the main database : ID, Name, Address and quantity with ID is the key
then if the imported CSV file only has two columns ID and Quantity then all the data in address and name columns becomes blank.

am i missing something?