A. SELECT * FROM 表名 where 表达式 B. SELECT * FROM 表名 order by 列名 C. SELECT 列1,列2 FROM 表名 group by 列名 D. SELECT 列1,sum(列2) FROM 表名 group by sum(列2) order by 列1
A. Select sum(*) from tb_student B. Select count(*) from tb_student C. Select count(学号) from tb_student D. Select max(*) from tb_student
A. union B. intersect C. except D. all
A. OR B. NOT IN C. NOT Between D. LIKE
A. SUM(列名) B. COUNT(*) COUNT(列名) D. AVG(列名)