以下选项中哪些是合法命名的标识符？
A: Username
B: 1name
C: user_name
D: user-name
E: user name
F: $username
G: name1
A: Username
B: 1name
C: user_name
D: user-name
E: user name
F: $username
G: name1
举一反三
- 在tb_name表中创建一个名为name_view的视图,并设置视图的属性为name、pwduser,执行语句是什么?( ) A: CREATE VIEW name_view(name,pwd,user)AS SELECT name.pwd,user FROM tb_mame; B: SHOW VIEW name_view(name,pwd,user) AS SELECT name,pwd,user FROM tb_mame: C: DROP VIEW name_view(name,pwd,user) AS SELECT name,pwd,user FROM tb_mame: D: SELECT * FROM name_view(name,pwd,user) AS SELECT name,pwd,user FROM tb_ name:
- 下列哪些SQL语句可以查询出User表中name为张三的记录（）。 A: SELECT * FROM User WHERE name = ’张三’ B: SELECT * FROM User WHERE name = ’张三’ LIMIT 0，1 C: SELECT * FROM User WHERE name LIKE ’张三’ D: SELECT * FROM User WHERE name LIKE ’%张三%’
- 4、以下选项，（）属于合法的标识符。 A: class B: 123username C: Hello_World D: user name
- 【多选题】下面语句可以实现查询user表中“zhangsan”的user,password,logins信息的是 A. select logins,user,password from user where name like ’%zhangsan%’; B. select user,password,logins, from user where name like ’zhangsan’; C. select password,logins,user from user where name=’zhangsan’ limit 1; D. select user,password,logins from user where name=’zhangsan’;
- The following can be used as a field ( ). A: user’s name B: user’s telephone C: product name D: product supplier