mysql change all values in a column

Question

I want to change all values in the tablecolumn \"Quellendatum\".

When the row-value is 2005-06-20 then it should be replaced with 2012-06-20. When the row-value is N

Answer 1

In MySql you can do:

UPDATE TABLENAME    
SET IDCOLUMN=VALUE    
WHERE IDCOLUMN=VALUE    
AND !isnull (IDCOLUMN)