Comparing Dates in a specific format in SQL Server - sql

Question

I have a column called "Mon-YY" (varchar(n) data type) in one of my tables which has values like:
Aug-12
Sep-12
Oct-12
Nov-12
Dec-12
Jan-13
Feb-13
Mar-13
Apr-13
May-13
Jun-13
I want to compare these values and retrieve the records from the table based on the date range specified.
I am assuming I'd need to convert the above values into DATE format. But I'm not sure then how do I keep track of days too.

Answer 1

You can use the DATEPART function, but you need to do it on a full date:
SELECT DATEPART(MM, 'Aug-12') --> error
SELECT DATEPART(MM', 01-Aug-12') --> 8
So try something like this:
SELECT
DATEPART(MM, CONCAT('01-', [Mon-YY])) AS TheMonth,
DATEPART(YYYY, CONCAT('01-', [Mon-YY])) AS TheYear
FROM myTable
ORDER BY TheYear, TheMonth

Answer 2

SELECT CONVERT (date, REPLACE (MyColumn, '-', ' 01 '))
FROM MyTable
Something like this should give you a date. It will always be the first of the month. You can use the expression in a WHERE clause with <, >, or BETWEEN. I don't know why you would need to keep track of them.

Answer 3

I used cast
-- example table and data
DECLARE #table table
(
[Mon-YY] varchar(20)
)
insert into #table values ('Aug-12')
insert into #table values ('Sep-12')
insert into #table values ('Oct-12')
insert into #table values ('Nov-12')
insert into #table values ('Dec-12')
insert into #table values ('Jan-13')
insert into #table values ('Feb-13')
insert into #table values ('Mar-13')
insert into #table values ('Apr-13')
insert into #table values ('May-13')
insert into #table values ('Jun-13')
select cast('01-' + [Mon-YY] as Date)
from #table

Answer 4

To convert these values to date you should use:
SELECT CONVERT(VARCHAR(20), '01 ' + [Mon-YY], 6) as BeginOfInterval
To get the last day of a month, you should use (look here):
SELECT DATEADD(s,-1,DATEADD(mm,
DATEDIFF(m,0,CONVERT(VARCHAR(20), '01 ' + [Mon-YY], 6))+1,0)) as EndOfInterval
Then you could use this two queries to get the first and last dates of interval.

Answer 5

A solution is to transform your column in something easier to sort like a number.
Bellow I transform the column in the full year followed by the month (numeric index 1 to 12) but this is used only in order by clause.
select *
from theTable
--where ???
order by case when right([mon-yy],2) <= 70 then '19' else '20' end +
right([mon-yy],2) +
case left([mon-yy],3)
when 'Jan' then '01'
when 'Feb' then '02'
when 'Mar' then '03'
when 'Apr' then '04'
when 'May' then '05'
when 'Jun' then '06'
when 'Jul' then '07'
when 'Aug' then '08'
when 'Sep' then '09'
when 'Oct' then '10'
when 'Nov' then '11'
when 'Dec' then '12'
end