If column equals

Question

I have a table below. I need when indicator = 0 then date = null

I have tried a case statement but receive errors. Any help would be appreciated.

     Select 
       Case when a.indicator = 0
          Then a.date = 0
             Else a.date
                End Date

      From TableA a

TableA

   Id         Date     Indicator
    1          1/1/17      0

Answer 1

select
  decode(a.indicator, 0, null, a.date) date
from
  tableA

Answer 2

Use this select :

SELECT 
CASE 
  WHEN A.INDICATOR = 0 THEN 
    NULL
  ELSE A.DATE
END DATE
FROM TABLEA A

Answer 3

What you want is:

SELECT CASE WHEN a.indicator = 0 THEN NULL ELSE a.date END AS 'Date' FROM TableA AS a

The reason a.date = 0 (or date = null) is wrong is that you are not assigning a new value to a.date but rather stating what value (null) should be returned from the case expression when it is true.

Answer 4

You can use this :

Select "Id", 
    Case 
        when "Indicator" <> 0 
            Then "Date" End AS Date1, 
    "Indicator"
From TableA;

Please notice I have reversed your logic and skipped the else null because this is anyway default if not used.

More about case: http://modern-sql.com/feature/case

SQL HERE

Answer 5

Select 
    Case a.indicator when 0
        Then null
            Else a.date
            End
 From TableA a