Dynamic SQL to populate a variable

Here's the WRONG way to do what I want. I need a way to populate a variable from the output of a dynamic query.

declare @.TableName sysname

set @.TableName = 'Customers'

delcare @.Output bigint

declare @.SQL varchar(max)

set @.SQL = 'select top 1 RowID from ' + @.TableName

select @.Output =

EXEC (@.SQL)

create function udf_GetDatabaseFingerPrint(

@.DBID bigint

)

begin

returns bigint

as

declare @.dbname sysname

, @.iBig bigint

, @.tSQL varchar(2000)

select @.dbName = Name from Master.Dbo.Sysdatabases where DBID = @.DBID

set @.tSQL = 'select sum(Rows) from ' + @.dbName + '.dbo.sysindexes'

set @.iBig = exec(@.tSQL)

return @.iBig

end

Number one, you cannot do this in a T-SQL function. Functions will not allow such things. You can use sp_executeSQL. In this case, something like this (and old example I had

declare @.objectId int,

exec sp_executeSQL

N'select @.objectId = max(object_id) from sys.objects',

N'@.objectId int output', @.objectId=@.objectId output

select @.objectId