摘要： 慢慢积累...1.绝对值 SQL:select abs(-1) valueO:select abs(-1) value from dual2.取整(大) S:select ceiling(-1.001) value O:select ceil(-1.001) value from dual3.取整（小） S:select floor(-1.001) value O:select floor(-1.001) value from dual4.取整（截取）S:select cast(-1.002 as int) value O:select trunc(-1.002) value from dua 阅读全文