摘要: 1.算数运算符 +, -, * /, DIV, %, MOD 在除法和模运算中,如果除数为0,将是非法除数,返回结果为NULL 2.比较运算符 = <>, != <=> //NULL的安全等于(NULL-safe) < <= > >= BETWEEN //x BETWEEN a AND b -> a 阅读全文
posted @ 2017-03-21 16:44 MicroCat 阅读(2659) 评论(0) 推荐(0)