Question

Does anyone know how to use transact sql to enumerate the column types within a transact sql result set. I want to do something like this (pseudo-code):

for each column in (select * from table1 where id=uniquekey)
{
if (column.type=uniqueidentifier){
insert into #table2(id) values (column.value)
}}
then do some stuff with #table2

But I need to do it from within transact sql, and I don’t know in advance what the structure of table1 will be.
Anyone know how? I’m using MS SQL 2005. In a nutshell I want all uniqueidentifier values for a specific record in table1 to be written to #table2.
Thanks!

Answer 1

Warning, not tested:

Create Table #Cols(ColName SysName)
Declare @More Bit
Declare CCol Cursor Local Fast_Forward For Select Column_Name From Information_Schema.Columns Where Table_Name = 'Table1' And Data_Type = 'UniqueIdentifier'
Declare @CCol SysName
Declare @SQL National Character Varying(4000)

Set @More = 1
Open CCol

While (@More = 1)
Begin
  Fetch Next From CCol Into @CCol
  If (@@Fetch_Status != 0)
    Set @More = 0
  Else
  Begin
    Set @SQL = N'Insert Into #Table2(ID) Select [' + @CCol + N'] From Table1'
    Execute (@SQL)
  End
End

Close CCol
Deallocate CCol

...