Issue on Update rows using CSV file

[VarunChandran]

Hi Team,

I am using a table called table 1 with 4 columns. Column 1, Column 2, column 3, column 4. Currently we have 5 records in table 1. Column 1 is the unique column.

Column 1 (Key)	Column 2	Column 3	Column 4
Student 1	80	70	50
Student 2	35	34	56
Student 3	89	34	45
Student 4	12	12	12
Student 5	34	45	45

Now I want to update the Student 1 and Student 2's Column 2 Data. So I prepared a CSV file like this

Column 1 (Key)	Column 2
Student 1	90
Student 2	90

When I upload this csv file It update the existing record for the specific column but also make other column values as null

Column 1 (Key)	Column 2	Column 3	Column 4
Student 1	90
Student 2	90
Student 3	89	34	45
Student 4	12	12	12
Student 5	34	45	45

Why other columns are changed to null even though I haven't mentioned the columns names in the csv file? 

@Marc_Dillon @Steve 

[TeeSee1]

I believe this answers you question (see here)