Question

I have a table like this named “Days”

Day 1    Day 2    Day 3    Day 4    Day 5    Day 6    Day 7
1        1        1        1        0        0        0
1        1        1        1        0        0        0

which has the corresponding details. Where 1 is ‘true’ and 0 is false.

DaY 1 - sunday
day 2- monday
day 3 - tuesday
day 4- wednesday
day5 - thursday
day 6 - friday
dayy 7- saturday

1 - denotes there is work on the given day
0 - denotes there is no work on the given day.

Given the details above i need to make column to table mapping
and need to generate a table like this , where i need to get the data only those which has flag 1

1   Sunday 
2   Monday 
3   Tuesday     
4   Wednesday

for the first record.

Answer 1

I believe you’re looking for something like the following:

select 
case when day1=1 then '1 Sunday' end Sunday,
case when day2=1 then '2 Monday' end Monday,
case when day3=1 then '3 Tuesday' end Tuesday,
case when day4=1 then '4 Wednesday' end Wednesday,
case when day5=1 then '5 Thursday' end Thursday,
case when day6=1 then '6 Friday' end Friday, 
case when day7=1 then '7 Saturday' end Saturday
from [table]
where day1+day2+day3+day4+day5+day6+day7 <> 7

Or those should be rows? Then you would need to unpivot the source data first like so:

select     
cast(substring(dayname, 4, 1) as tinyint) as DayNumber, 
case cast(substring(dayname, 4, 1) as tinyint) 
when 1 then 'Sunday'
when 2 then 'Monday'
when 3 then 'Tuesday'
when 4 then 'Wednesday'
when 5 then 'Thursday'
when 6 then 'Friday'
when 7 then 'Saturday' end [DayName]
, DayFlag 
from (select * from [table] t where day1+day2+day3+day4+day5+day6+day7 <> 7) f
unpivot 
(
DayFlag for DayName in ([day1], [day2], [day3], [day4], [day5], [day6], [day7])
) unpvt
where DayFlag = 1 --is this what you need?