在 SQL 语句“select * from student”中，“*”号的含义是
举一反三
- 根据用户在文本框txtName中输入的姓名对Student表进行查询，以下SQL语句定义正确的是__________________。 A: String sql=Select * from Student where Sname=+txtName.getText(); B: String sql=Select * from Student where Sname='+txtName.getText()+'; C: String sql=Select * from Student where Sname like +txtName.getText(); D: String sql=Select * from Student where Sname like '+txtName.getText()+';
- 查询student表中的gender字段（gender代表性别），使其查询记录中不能出现重复值的SQL语句是（1.0分） A: SELECT gender FROM student; B: SELECT DISTINCT * FROM student; C: SELECT DISTINCT gender FROM student; D: SELECT * FROM student;
- 下列 SQL 语句select * from student where sno = '05880101'union select * from student where sno = '05880102'与此查询语句等价的选项是( )。 A: select * from student where sno= '05880101' and sno= '05880102' B: select * from student where sno= '05880101' or sno= '05880102' C: select * from student where sno= '05880101' D: select * from student where sno= '05880102'
- 表student中的包含两个字段，整型的id，字符串型的name。只显示表student中name列记录的SQL语句正确的是（） A: select name from student B: select * from student C: select from name in student D: select name
- 下列选项中,能够按照 score 由高到低显示 student 表中记录的 SQL 语句是 A: SELECT* FROM student ORDER BY score ; B: SELECT* FROM student ORDER BY score ASC ; C: SELECT * FROM student ORDER BY score DESC ; D: SELECT* FROM student GROUP BY score DESC ;