查詢上面這種表：

1.查詢表中所有資料：MariaDB [test]> select * from bug;

2.查詢系統為11.3的bug列表：MariaDB [test]> select * from bug where system="iOS11.3";

3.設定返回的記錄行數：MariaDB [test]> select * from bug where system="iOS11.3" limit 1;

4.設定開始查詢的向下偏移量;MariaDB [test]> SELECT * FROM BUG LIMIT 2 OFFSET 1;

5.模糊查詢，查詢testname 以3結尾：MariaDB [test]> select * from bug where testername like "%3";

6.從bug表和tester表中，選中不同的name: select testername from bug union select name from tester;

7.從bug表和tester表中，選中重複的name:MariaDB [test]> select testername from bug union all select name from tester;

8.按iD升序排列：MariaDB [test]> select * from bug order by id;

9.按id降序排列：MariaDB [test]> select * from bug order by id desc;

10.按system分組，並統計每種system有多少個：MariaDB [test]> select system,count(*) from bug group by(system);

還可以用sum(),avg()等

11.內連線

select a.runoob_count,b.submission_date from tb1,a inner join tb2,b on a.runoob_author =b.runoob_author;

12.左連線

select a.runoob_count,b.submission_date from tb1,a left join tb2,b on a.runoob_author =b.runoob_author;

13.右連線

select a.runoob_count,b.submission_date from tb1,a right join tb2,b on a.runoob_author =b.runoob_author;