下列关于SQL 语句“ SELECT* FROM user WHERE firstname =张;”的描述中,正确的是
A. 查询姓“张”的用户的一条记录的所有信息
B. 查询姓“张”的用户的所有记录的所有信息
C. 执行 SQL 语句时出现错误
D. 以上说法不正确
查看答案
已知用户表 user 有字段 age ,若想查询年龄为18或20的用户,则应使用的 SQL 语句是
A. SELET* FROM user WHERE age =18 OR age =20;
B. SELECT* FROM user WHERE age =18&& age =20;
C. SELECT* FROM user WHERE age =18 AND age =20;
D. SELECT* FROM user WHERE age =(18,20);
下列选项中,代表匹配任意长度字符串的通配符是
A. %
B. *
C. _
D. ?
下列选项中,用于查询 student 表中 id 值在1,2,3范围内的记录的 SQL 语句是
A. SELECT* FROM student WHERE id =1,2,3;
B. SELECT* FROM student WHERE ( id =1, id =2, id =3);
C. SELECT* FROM student WHERE id in (1,2,3);
D. SELECT* FROM student WHERE id in 1,2,3;
已知 student 表有姓名字段 name。若想查询所有姓“王”的学生,并且姓名由三个字符组成,则应使用的SQL 语句是
A. SELECT* FROM student WHERE name LIKE ‘王__’;
B. SELECT* FROM student WHERE name LIKE ‘王%_’;
C. SELECT* FROM student WHERE name LIKE ‘王%’;
D. SELECT* FROM student WHERE name =’王__’;
微信支付 
支付宝支付