Create a table without knowing its columns in SQL - sql

Question

How can I create a table without knowing in advance how many and what columns it exactly holds?
The idea is that I have a table DATA that has 3 columns : ID, NAME, and VALUE
What I need is a way to get multiple values depending on the value of NAME - I can't do it with simple WHERE or JOIN (because I'll need other values - with other NAME values - later on in my query).
Because of the way this table is constructed I want to PIVOT it in order to transform every distinct value of NAME into a column so it will be easier to get to it in my later search.
What I want now is to somehow save this to a temp table / variable so I can use it later on to join with the result of another query...
So example:
Columns:
CREATE TABLE MainTab
(
id int,
nameMain varchar(max),
notes varchar(max)
);
CREATE TABLE SecondTab
(
id int,
id_mainTab, int,
nameSecond varchar(max),
notes varchar(max)
);
CREATE TABLE DATA
(
id int,
id_second int,
name varchar(max),
value varchar(max)
);
Now some example data from the table DATA:
| id | id_second_int | name | value |
|-------------------------------------------------------|
| 1 | 5550 | number | 111115550 |
| 2 | 6154 | address | 1, First Avenue |
| 3 | 1784 | supervisor | John Smith |
| 4 | 3467 | function | Marketing |
| 5 | 9999 | start_date | 01/01/2000 |
::::
Now imagine that 'name' has A LOT of different values, and in one query I'll need to get a lot of different values depending on the value of 'name'...
That's why I pivot it so that number, address, supervisor, function, start_date, ... become colums.
This I do dynamically because of the amount of possible columns - it would take me a while to write all of them in an 'IN' statement - and I don't want to have to remember to add it manually every time a new 'name' value gets added...
herefore I followed http://sqlhints.com/2014/03/18/dynamic-pivot-in-sql-server/
the thing is know that I want the result of my execute(#query) to get stored in a tempTab / variable. I want to use it later on to join it with mainTab...
It would be nice if I could use #cols (which holds the values of DATA.name) but I can't seem to figure out a way to do this.
ADDITIONALLY:
If I use the not dynamic way (write down all the values manually after 'IN') I still need to create a column called status. Now in this column (so far it's NULL everywhere because that value doesn't exist in my unpivoted table) i want to have 'open' or 'closed', depending on the date (let's say i have start_date and end_date,
CASE end_date
WHEN end_date < GETDATE() THEN pivotTab.status = 'closed'
ELSE pivotTab.status = 'open'
Where can I put this statement? Let's say my main query looks like this:
SELECT * FROM(
(SELECT id_second, name, value, id FROM TABLE_DATA) src
PIVOT (max(value) FOR name IN id, number, address, supervisor, function, start_date, end_date, status) AS pivotTab
JOIN SecondTab ON SecondTab.id = pivotTab.id_second
JOIN MainTab ON MainTab.id = SecondTab.id_mainTab
WHERE pivotTab.status = 'closed';

Answer 1

Well, as far as I can understand - you have some select statement and just need to "dump" its result to some temporary table. In this case you can use select into syntax like:
select .....
into #temp_table
from ....
This will create temporary table according to columns in select statement and populate it with data returned by select datatement.
See MDSN for reference.