oracle 数据类型判断

近日看oracle文档，发现oralce的一个特性，以往还真没发现

Floating-Point Conditions


不能贴图片，用文字记录一下
is nan：         --matches the NAN special value,which means "not a number"(introduced in Oracle 10g)
is infinite：    --matches infinite binary_float and binary_double values(introduced in Oracle 10g)

文档上提供的例子：
SELECT COUNT(*) FROM employees
  WHERE commission_pct IS NOT NAN;

SELECT last_name FROM employees
  WHERE salary IS NOT INFINITE;