1. DECODE (expression, search, result [, search2, result2]... [,default])
SELECT supplier_name,
DECODE(supplier_id, 1000, 'IMB',
1001, 'Microsoft',
1002, 'HP',
'Gateway') result
FROM suppliers;
2. 增加时间：
DATEADD( interval, number, date )
SELECT DATEADD(yy, 1, '2014/04/28');
Result: '2015-04-28 00:00:00.000'
