條件和排序
員工ID爲90的
select * from employees e where e.department_id = 90;
員工工資小於4400的
select * from employees e where e.salary < 4400;
between…and在倆個值之間
select * from employees ewhere e.salary between 4400 and 9000;
員工工資在4400到9000之間，包含4400和9000
前面的值小，後面的值大，否則前大後小查詢不到數據
部門ID爲90、60的員工
select * from employees e where e.department_id in (90,60);
員工姓名g結尾的
select * from employees e where e.last_name like '%g';
員工姓名中含有i的
select * from employees e where e.last_name like '%i%';
員工姓名第二位是o的
select * from employees e where e.last_name like '_o%';
員工ID爲空的員工
SELECT * FROM EMPLOYees e where e.department_id is null;
並且 和 and 或者 or
工資一萬以上並且工作名稱含有MAN字符的員工
select * from employees e where e.salary > 10000 and e.job_id like '%MAN%';
工資一萬以上或者工作名稱含有MAN字符的員工
select * from employees e where e.salary > 10000 or e.job_id like '%MAN%';
not 不是 不爲
員工ID不爲空的員工
SELECT * FROM EMPLOYees e where e.department_id is not null;
員工ID不是90、60的員工
SELECT * FROM EMPLOYees e where e.department_id not in (90，60);
escape 轉義
select * from t_char where a like '%#%%' escape '#';
escape後的’#'可以指定任意字符
select * from t_char where a like '%z%%' escape 'z';
order by 默認升序asc 降序desc
部門ID不在90的員工並按照日期升序
SELECT * FROM EMPLOYees e where e.department_id not in (90) order by e.hire_date;
部門ID不在90的員工並按照日期降序
SELECT * FROM EMPLOYees e where e.department_id not in (90) order by e.hire_date desc;
