decode (expression, search_1, result_1)如果 expression结果＝search_1结果，则返回result_1，类似 if elsedecode (expression, search_1, result_1, search_2, result_2)decode (expression, search_1, result_1, search_2, result_2, ...., search_n, result_n)decode (expression, search_1, result_1, default)如果 expression结果＝search_1结果，则返回result_1，否则反回defaultdecode (expression, search_1, result_1, search_2, result_2, default)decode (expression, search_1, result_1, search_2, result_2, ...., search_n, result_n, default)decode函数比较表达式和搜索字，如果匹配，返回结果；如果不匹配，返回default值；如果未定义default值，则返回空值。如：select (a/b*100) as percent from t如果b为0会出现被除数为0解决：select decode(b,0,0,a/b*100) as percent from t
转载于:https://www.cnblogs.com/robertsun/p/4211366.html
