How to alter the data type of a field

I want to change the filed type form nvarchar(5) to varchar(10)
There is no need to reserve the data in the filed.
How can I do with SQL command?Use the ALTER TABLE command:
ALTER TABLE my_table
ALTER COLUMN my_column varchar(10)
--
HTH
Kalen Delaney, SQL Server MVP
http://sqlblog.com
"ad" <flying@.wfes.tcc.edu.tw> wrote in message
news:umBJWlAGHHA.4652@.TK2MSFTNGP04.phx.gbl...
>I want to change the filed type form nvarchar(5) to varchar(10)
> There is no need to reserve the data in the filed.
> How can I do with SQL command?
>|||Thank,
Can I determinate if the data type varchar before ater it.
Like
if type(my_table.my_column) <>varchar(10)
ALTER TABLE my_table ALTER COLUMN my_column varchar(10)
"Kalen Delaney" <replies@.public_newsgroups.com> ¼¶¼g©ó¶l¥ó·s»D:O30DznAGHHA.2128@.TK2MSFTNGP03.phx.gbl...
> Use the ALTER TABLE command:
> ALTER TABLE my_table
> ALTER COLUMN my_column varchar(10)
> --
> HTH
> Kalen Delaney, SQL Server MVP
> http://sqlblog.com
>
> "ad" <flying@.wfes.tcc.edu.tw> wrote in message
> news:umBJWlAGHHA.4652@.TK2MSFTNGP04.phx.gbl...
>>I want to change the filed type form nvarchar(5) to varchar(10)
>> There is no need to reserve the data in the filed.
>> How can I do with SQL command?
>|||What version?
--
HTH
Kalen Delaney, SQL Server MVP
http://sqlblog.com
"ad" <flying@.wfes.tcc.edu.tw> wrote in message
news:OD2cMPBGHHA.5104@.TK2MSFTNGP03.phx.gbl...
> Thank,
> Can I determinate if the data type varchar before ater it.
> Like
> if type(my_table.my_column) <>varchar(10)
> ALTER TABLE my_table ALTER COLUMN my_column varchar(10)
>
>
> "Kalen Delaney" <replies@.public_newsgroups.com>
> ¼¶¼g©ó¶l¥ó·s»D:O30DznAGHHA.2128@.TK2MSFTNGP03.phx.gbl...
>> Use the ALTER TABLE command:
>> ALTER TABLE my_table
>> ALTER COLUMN my_column varchar(10)
>> --
>> HTH
>> Kalen Delaney, SQL Server MVP
>> http://sqlblog.com
>>
>> "ad" <flying@.wfes.tcc.edu.tw> wrote in message
>> news:umBJWlAGHHA.4652@.TK2MSFTNGP04.phx.gbl...
>>I want to change the filed type form nvarchar(5) to varchar(10)
>> There is no need to reserve the data in the filed.
>> How can I do with SQL command?
>>
>|||my version is SQLServer 2005 Express
"Kalen Delaney" <replies@.public_newsgroups.com> ¼¶¼g©ó¶l¥ó·s»D:ORvLXDCGHHA.4804@.TK2MSFTNGP03.phx.gbl...
> What version?
> --
> HTH
> Kalen Delaney, SQL Server MVP
> http://sqlblog.com
>
> "ad" <flying@.wfes.tcc.edu.tw> wrote in message
> news:OD2cMPBGHHA.5104@.TK2MSFTNGP03.phx.gbl...
>> Thank,
>> Can I determinate if the data type varchar before ater it.
>> Like
>> if type(my_table.my_column) <>varchar(10)
>> ALTER TABLE my_table ALTER COLUMN my_column varchar(10)
>>
>>
>> "Kalen Delaney" <replies@.public_newsgroups.com> ¼¶¼g©ó¶l¥ó·s»D:O30DznAGHHA.2128@.TK2MSFTNGP03.phx.gbl...
>> Use the ALTER TABLE command:
>> ALTER TABLE my_table
>> ALTER COLUMN my_column varchar(10)
>> --
>> HTH
>> Kalen Delaney, SQL Server MVP
>> http://sqlblog.com
>>
>> "ad" <flying@.wfes.tcc.edu.tw> wrote in message
>> news:umBJWlAGHHA.4652@.TK2MSFTNGP04.phx.gbl...
>>I want to change the filed type form nvarchar(5) to varchar(10)
>> There is no need to reserve the data in the filed.
>> How can I do with SQL command?
>>
>>
>|||This query returns all the datatypes and lengths for columns in a given
table. You should be able to figure out how to write your IF statement from
this information:
SELECT object_name(object_id) as [object_name], c.name as column_name,
t.name as type_name, c.max_length
FROM sys.types t join sys.columns c
ON t.user_type_id = c.system_type_id
WHERE object_name(object_id) = 'my_table'
--
HTH
Kalen Delaney, SQL Server MVP
http://sqlblog.com
"ad" <flying@.wfes.tcc.edu.tw> wrote in message
news:eoktgyCGHHA.2456@.TK2MSFTNGP06.phx.gbl...
> my version is SQLServer 2005 Express
> "Kalen Delaney" <replies@.public_newsgroups.com>
> ¼¶¼g©ó¶l¥ó·s»D:ORvLXDCGHHA.4804@.TK2MSFTNGP03.phx.gbl...
>> What version?
>> --
>> HTH
>> Kalen Delaney, SQL Server MVP
>> http://sqlblog.com
>>
>> "ad" <flying@.wfes.tcc.edu.tw> wrote in message
>> news:OD2cMPBGHHA.5104@.TK2MSFTNGP03.phx.gbl...
>> Thank,
>> Can I determinate if the data type varchar before ater it.
>> Like
>> if type(my_table.my_column) <>varchar(10)
>> ALTER TABLE my_table ALTER COLUMN my_column varchar(10)
>>
>>
>> "Kalen Delaney" <replies@.public_newsgroups.com>
>> ¼¶¼g©ó¶l¥ó·s»D:O30DznAGHHA.2128@.TK2MSFTNGP03.phx.gbl...
>> Use the ALTER TABLE command:
>> ALTER TABLE my_table
>> ALTER COLUMN my_column varchar(10)
>> --
>> HTH
>> Kalen Delaney, SQL Server MVP
>> http://sqlblog.com
>>
>> "ad" <flying@.wfes.tcc.edu.tw> wrote in message
>> news:umBJWlAGHHA.4652@.TK2MSFTNGP04.phx.gbl...
>>I want to change the filed type form nvarchar(5) to varchar(10)
>> There is no need to reserve the data in the filed.
>> How can I do with SQL command?
>>
>>
>>
>