The UNION ALL keywords

By default, the UNION keyword excludes duplicate rows. To retain the duplicate values, add the optional keyword ALL, as the following query shows.
Figure 1: Query
SELECT stock_num, manu_code FROM stock
   WHERE unit_price < 25.00
UNION ALL
SELECT stock_num, manu_code FROM items
   WHERE quantity > 3 
   ORDER BY 2
   INTO TEMP stock item;
The query uses the UNION ALL keywords to unite two SELECT statements and adds an INTO TEMP clause after the final SELECT to put the results into a temporary table. It returns the same rows as Query but also includes duplicate values.
Figure 2: Query result
stock_num manu_code

        9 ANZ
        5 ANZ
        9 ANZ
        5 ANZ
        9 ANZ
       ⋮
        5 NRG
        5 NRG
      103 PRC
      106 PRC
        5 SMT
        5 SMT