Update Cell based on other cell Fieldcalculator

Question

I want to search for certain values in a column. If that value is found, I want to update another a cell in the same row, other column.

I tried

CASE WHEN "column1" = 9 THEN "column2" = 'SA' ELSE "column2" END

That did not work. How would I approach that?

Answer 1

Using QGIS 2.16, in the field calculator, set it up to update an existing field (the one you want the changes to take place). Then write a CASE WHEN statement like this:

CASE WHEN "column1" = 9 THEN 'SA' ELSE "column2" END

You don't need to reference the column you wish to change as the field calculator takes care of that.

EDIT:

For multiple values change the expression to:

CASE 
WHEN "column1" = 9 THEN 'SA' 
WHEN "column1" = 8 THEN 'TB'
WHEN "column1" = 7 THEN 'UC'
ELSE "column2"
END