Dynamic pivot data with multiple datatypes - sql

Question

I have a trick problem with a pivot table to make:
I have a table which looks like:
id table object name type nvarchar date int bit
1 1 2 name 1 tables NULL NULL NULL
2 1 2 name 1 columns NULL NULL NULL
3 1 2 name 1 datatypes NULL NULL NULL
4 1 2 name 1 _users NULL NULL NULL
1 1 3 active 3 NULL NULL NULL 1
2 1 3 active 3 NULL NULL NULL 1
3 1 3 active 3 NULL NULL NULL 1
4 1 3 active 3 NULL NULL NULL 1
the output should look like:
id name active
1 tables 1
2 columns 1
3 datatypes 1
4 _users 1
Based upon the "type" I should put the correct data from the column in it, these columns are formated in nvarchar, bit, datetime, int, ect.
The "id" is the row id, the "name, active" comes from the name column and the values from nvarchar, date, int and bit columns.
UPDATE: the columns like nvarchar, date, int and bit (and most other SQL formats) are actually contain this type of data. The column "type" gives which column contains the data to being used, so if "type" is "1", than I want to use the "nvarchar" if "type" is "3" than I want to use the "bit" which contains really a bit and not a nvarchar. In the Pivot I want to have the bit under "active" column, if I have in the example a 3th column (name) for example "activation_date" I want to see a third column with the value (type = 2) from the date column.
I am lost in this, please help

Answer 1

Assuming there's only one not null column for each row:
with cte as (
select
id,
name,
coalesce(
[nvarchar],
convert(nvarchar(max), [date], 120),
cast([int] as nvarchar(max)),
cast([bit] as nvarchar(max))
) as value
from Table1 as t
)
select
id,
max(case when [name] = 'name' then value end) as [name],
max(case when [name] = 'active' then value end) as [active]
from cte
group by id
sql fiddle demo
But I must warn you, this types of database schema is not best way to use SQL.
If you want to do this dynamically without hardcoding columns:
declare #stmt nvarchar(max)
select #stmt =
isnull(#stmt + ', ', '') +
'max(case when [name] = ''' + name + ''' then value end) as ' + quotename([name])
from (select distinct [name] from Table1) as t
select #stmt = '
with cte as (
select
id,
name,
coalesce(
[nvarchar],
convert(nvarchar(max), [date], 120),
cast([int] as nvarchar(max)),
cast([bit] as nvarchar(max))
) as value
from Table1 as t
)
select
id, ' + #stmt + '
from cte
group by id
'
exec sp_executesql
#stmt = #stmt
sql fiddle demo
If you have some Mapping table like this:
name value
--------------------
name nvarchar
active bit
you can use this query:
declare #stmt nvarchar(max)
select #stmt =
isnull(#stmt + ', ', '') +
'max(case when [name] = ''' + name + ''' then [' + value + '] end) as ' + quotename([name])
from Mapping
select #stmt = '
select
id, ' + #stmt + '
from Table1
group by id
'
exec sp_executesql
#stmt = #stmt
sql fiddle demo