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Posted by Tony Rogerson on 05/05/06 11:29
> Using integer or char(8) for dates is in my opinion an even worse
> solution,
> as you run the risk of getting dates like 20060230 and that in the system.
Well not really, its the same argument i'd have with a time component of the
datetime, both are fixed with a check constraint.
I've not mentioned the space issue - 4 bytes ve 8 bytes which can amount to
a lot more IO for larger trading systems.....
check( ISDATE( 20060230 ) = 1 ) which is simpler then the check constraint
needed for slicing off / checking for the time component!
Tony.
--
Tony Rogerson
SQL Server MVP
http://sqlserverfaq.com - free video tutorials
"Erland Sommarskog" <esquel@sommarskog.se> wrote in message
news:Xns97BA66AF76B25Yazorman@127.0.0.1...
> Tony Rogerson (tonyrogerson@sqlserverfaq.com) writes:
>> Presumeably you also have a computed column that strips away the time
>> component so only the date gets passed back to the client?
>
> Computed column? Hey, this system started its life in SQL Server 4.x. And
> you cannot accuse for being too quick to leave SQL 6.5. I think we have
> two computed columns in the system.
>
> Yes, the time portion is a bit of noice in Query Analyzer. For the client,
> it is a non-issue.
>
>> All the trading systems I've worked with ALL use the integer data type to
>> hold pure dates.
>
> One of our competitors seems to go by char(8). (They're not using SQL
> Server. Their system runs on AS 400, so I guess it's DB2.) We have taken
> over several of their customers and converted their data to our system.
> I've seen some completely hilarous dates there.
>
> Using integer or char(8) for dates is in my opinion an even worse
> solution,
> as you run the risk of getting dates like 20060230 and that in the system.
> --
> Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se
>
> Books Online for SQL Server 2005 at
> http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/books.mspx
> Books Online for SQL Server 2000 at
> http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx
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