How to select as much records as indicated by the value from database - sql

Question

I have one table in relational database Sybase ASE, with few columns. Three of them looks like this example:
_____________
| Product |
---------------
| ProductId |
| Name |
| Quantity |
_____________
So we have some records:
__________________________________
| ProductId | Name | Quantity |
----------------------------------
| 1 | pants | 2 |
| 2 | shirt | 1 |
| 3 | sweater | 3 |
----------------------------------
I need to get every name as many times as 'Quantity' of this product.
So the result should looks like:
pants
pants
shirt
sweater
sweater
sweater
If somebody have any idea how can I do this, please help me.
EDIT
2014-01-24 14:17 UTC+1
I'd like to thanks everybody. Gordon's solution is realy nice, but for my situation (bigger Quantity) I can't use that sql. I try do somethnig like 333kenshin's and simon's solutions but without cursor. I do somthnig like this:
IF OBJECT_ID('#TEMP') is not null
DROP TABLE #TEMP
create TABLE #TEMP (Name varchar(255))
DECLARE #Name varchar(255)
DECLARE #Quant INT
DECLARE #prodId INT
SET #prodId = 1
WHILE (EXISTS(SELECT 1 FROM product WHERE productID = #prodId))
BEGIN
SELECT
#Name = Name
#Quant = Quantity
FROM Product
DECLARE #i INT
SET #i = 1
WHILE #i <= #Quant
BEGIN
insert into #TEMP
values(#Name)
SELECT #i=#i+1
END
SELECT #prodId = #prodId + 1
END
select * from #TEMP
drop table #TEMP
For me, and my DB it was fastest solution. So thanks a lot for every answers.

Answer 1

To do this, you need a series of integers. You can generate one manually:
select p.name
from product p join
(select 1 as n union all select 2 union all select 3 union all select 4
) n
on n.n <= p.quantity;
This will work if quantity is not too big and you can put in the values in n.

Answer 2

The correct way to do this is temp table + cursors:
create a temp table
create cursor to iterate through Product table
within the cursor, create an inner WHILE loop
exit the loop and finally select the temp table
The following isn't 100% correct Sybase syntax, but it's pretty close.
-- 1: temp table
select productName into #TEMP
-- 2: cursor
declare
#productName char(10),
#quantity int
declare ProductRead CURSOR for
select
productName,
quantity
from
Product
OPEN ProductRead
FETCH ProductRead
INTO
#productName,
#quantity
WHILE (##sqlstatus=0)
BEGIN
-- 3: inner for loop
DECLARE #i INT
SET #i = 1
WHILE #i <= #quantity
BEGIN
insert #productName into #TEMP
END
END
-- 4: final result set
select productName from #TEMP

Answer 3

You could use a temporary table. Select all your product rows, then loop through each row returned. For each product, loop Quantity times and in the loop insert the product into the temp table. I'm not a Sybase user, so I can't give you the syntax but you would have a stored procedure which would do something like:
select all rows from product into a cursor
for each row
for i = 1 to row.Quantity
insert into temp (Name) values (row.Name)
next
end loop
select * from temp and return it
It's a pretty eccentric requirement, though.
EDIT: Gordon's solution is neat though! If n never gets too big I'd go with that!