在SQL中的情况

Question

I have table when contains who's two column contains data/null , i want to capture only rows which is not null.

example of t1

Application_channel | reason_for_joining
            call    | null
            null    | do not wish to provide
            null    | null

I want output as

Status
 call
 do not wish to provide

query i wrote is somthing like:-

select case 
when reason_for_joining is null and application_channel is not null then       application_channel
when application_channel is null and reason_for_joining is not null then 
reason_for_joining else application_channel end as status
from t1

the problem is its also taking null when both the column has null value which i dont want. Any help much appreciated.

Answer 1

He also wanted to filter those that are empty, so it would be:

select coalesce(Application_channel, reason_for_joining) as status
from t1
where coalesce(Application_channel, reason_for_joining) is not null

Alternatively you could also filter like this:

WHERE Application_channel IS NOT NULL OR reason_for_joining IS NOT NULL

Answer 2

You want coalesce() :

select coalesce(Application_channel, reason_for_joining) as status
from t1

Answer 3

Is case of two parameter ISNULL also do same work

select ISNULL('call',null),isnull(null,'do not')

so in you query

select ISNULL(Application_channel, reason_for_joining) as status
from t1
where ISNULL(Application_channel, reason_for_joining) is not null