Convert To Proper Date

I read some questions where questioners ask "Sometimes client gives data where dates are expressed as float or integer values.
How do I find maximum date?".

Ex
March 02, 2006 can be expressed as
02032006.0
020306
2032006
20306
020306.0000
2032006
Assuming the values are expressed in dmy format

The possible way is convert that value into proper date so that all types of date related calculations can be done
Create function proper_date (@date_val varchar(25))
returns datetime
as
Begin
Select @date_val=
case when @date_val like '%.0%' then substring(@date_val,1,charindex('.',@date_val)-1)
else @date_val
end
return
cast(
case
when @date_val like '%[a-zA-Z-/]%' then case when ISDATE(@date_val)=1 then @date_val else NULL end
when len(@date_val)=8 then right(@date_val,4)+'-'+substring(@date_val,3,2)+'-'+left(@date_val,2)
when len(@date_val)=7 then right(@date_val,4)+'-'+substring(@date_val,2,2)+'-0'+left(@date_val,1)
when len(@date_val)=6 then
case when right(@date_val,2)<50 then '20'
else '19'
end
+right(@date_val,2)+'-'+substring(@date_val,3,2)+'-'+left(@date_val,2)
when len(@date_val)=5 then
case when right(@date_val,2)<50 then '20'
else '19'
end
+right(@date_val,2)+'-'+substring(@date_val,2,2)+'-0'+left(@date_val,1)
else
case when ISDATE(@date_val)=1 then @date_val else NULL end
end
as datetime
)
End

This function will convert them into proper date
select
dbo.proper_date('02032006.0') as proper_date,
dbo.proper_date('020306.000') as proper_date,
dbo.proper_date('02032006') as proper_date,
dbo.proper_date('020306') as proper_date,
dbo.proper_date('20306') as proper_date,
dbo.proper_date('020306') as proper_date

Apart from converting integer or float values to date, it will also convert date strings to date
Select
dbo.proper_date('March 2, 2006') as proper_date,
dbo.proper_date('2 Mar, 2006') as proper_date,
dbo.proper_date('2006 Mar 2') as proper_date,
dbo.proper_date('2-Mar-2006') as proper_date,
dbo.proper_date('3/02/2006') as proper_date,
dbo.proper_date('02-03-2006') as proper_date,
dbo.proper_date('2006/03/02') as proper_date,
dbo.proper_date('March 2006') as proper_date,
dbo.proper_date('2 Mar 2006') as proper_date


Madhivanan

Failing to plan is Planning to fail