SQL Server CAST Usage

Hi Experts,
My sql is;
select  cast(MyTable.MyField1 as varchar(5)) from MyTable

My field is;
COLUMN_NAME      DATA_TYPE      TYPE_NAME
MyField1           5                       smallint

I wonder What is the difference between;
1) cast(MyTable.MyField1 as varchar(5))
2) cast(MyTable.MyField1 as varchar)

Thanks,
LVL 5
kosturdurAsked:
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boogiefromzkCommented:
varchar(5) is varchar, limited with 5 characters length
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Guy Hengel [angelIII / a3]Billing EngineerCommented:
http://msdn.microsoft.com/en-us/library/ms187928.aspxlength    Is an optional integer that specifies the length of the target data type. The default value is 30. so:2) cast(MyTable.MyField1 as varchar)would be the same as2) cast(MyTable.MyField1 as varchar(30) )
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Mohit VijayCommented:
varchar(5) will allow 5 character space and only varchar will decide space at run time, best way is to use varchar(5), static allocation.
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auke_tCommented:
Hi,

a smallint can be anyting between -2^15 (-32,768) to 2^15-1 (32,767). So you'd better use varchar(6)! ;-)


SELECT cast(-32768 as varchar(5))

SELECT cast(-32768 as varchar(6))

Cheers!

Auke
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kosturdurAuthor Commented:
3 helpfull comments so 3 answers made me increase the points
0
kosturdurAuthor Commented:
Thanks all
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Microsoft SQL Server

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