您好，登录后才能下订单哦！
密码登录
登录注册
点击 登录注册 即表示同意《亿速云用户服务条款》
choose two
Which two statenents are tue about the COUNT function?
A) It can only be used for NUMBER data types.
B) COUNT (DISTINCT inv_amt) returns the number of rows excluding rows containing dupicates and NULLs in the INV_AMT column
C) COUNT(*) returns the number of rows in a table including duplicate rows and rows containing NULLs in any column.
D) A SELECT statement using the COUNT function with a DISTINCT keyword cannot have a WHERE clause.
E) COUNT(inv_amt) returns the number of rows in a table including rows with NULL in the INV_AMT column.
Answer：：BC
(解析：count 对于 null 值是忽略的;可以与 where 一起使用。)
免责声明：本站发布的内容（图片、视频和文字）以原创、转载和分享为主，文章观点不代表本网站立场，如果涉及侵权请联系站长邮箱：is@yisu.com进行举报，并提供相关证据，一经查实，将立刻删除涉嫌侵权内容。