Tutorial by Examples

The UNION operator is used to combine the result-set (only distinct values) of two or more SELECT statements. Query: (To selects all the different cities (only distinct values) from the "Customers" and the "Suppliers" tables) SELECT City FROM Customers UNION SELECT City FROM ...

UNION ALL to select all (duplicate values also) cities from the "Customers" and "Suppliers" tables. Query: SELECT City FROM Customers UNION ALL SELECT City FROM Suppliers ORDER BY City; Result: Number of Records: 12 City ------- Aachen Albuquerque Anchorage Ann A...

UNION ALL to select all(duplicate values also) German cities from the "Customers" and "Suppliers" tables. Here Country="Germany" is to be specified in the where clause. Query: SELECT City, Country FROM Customers WHERE Country='Germany' UNION ALL SELECT City, Count...