SQL

mysql case when on date

SELECT
  id,
  CASE
    WHEN date_activated > '2011-11-23 18:30:00' THEN 'after'
    WHEN date_activated > '2010-01-20 00:00:00' THEN 'before'
    ELSE 'not yet'
  END AS date_note
FROM table1;

mysql case when or

SELECT
    CASE 
        WHEN
            column IS NULL OR another_column = 1
        THEN
            'yes' 
        ELSE
            'no' 
    END AS 'MyData'
FROM
    table_name;

mysql case when in select

SELECT CASE col1
	WHEN 'agree' THEN 'Ok'
	WHEN 'disagree' THEN 'Ko'
    ELSE
        CASE 
            WHEN col2 >= 1 THEN 'Ko'
            ELSE 'Maybe'
        END
END AS my_result
FROM table_name;