You can use the FIRST clause to select the first rows
that result from a union query. The following query uses a FIRST clause
to return the first five rows of a union between the stock and items tables.Figure 1: Query
SELECT FIRST 5 DISTINCT stock_num, manu_code
FROM stock
WHERE unit_price < 55.00
UNION
SELECT stock_num, manu_code
FROM items
WHERE quantity > 3;