我是SQL新手，正在练习Oracle 10g XE上提供的HR模式。 这是个问题： 编写一个查询，从部门编号80中选择除销售代表之外的所有员工的姓名，职位，工资和部门编号。
我的疑问是：
select first_name||' '||last_name "Employee Name"
, job_id, salary, department_id
from employees
where not( job_id='SA_REP' and department_id=80 )
order by department_id;
输出：
Employee Name JOB_ID SALARY DEPARTMENT_ID
---------------------------------------------- ---------- ---------- -------------
Jennifer Whalen AD_ASST 4400 10
Michael Hartstein MK_MAN 13000 20
Pat Fay MK_REP 6000 20
Den Raphaely PU_MAN 11000 30
Alexander Khoo PU_CLERK 3100 30
Shelli Baida PU_CLERK 2900 30
Sigal Tobias PU_CLERK 2800 30
Guy Himuro PU_CLERK 2600 30
Karen Colmenares PU_CLERK 2500 30
Susan Mavris HR_REP 6500 40
Matthew Weiss ST_MAN 8000 50
Adam Fripp ST_MAN 8200 50
Payam Kaufling ST_MAN 7900 50
Shanta Vollman ST_MAN 6500 50
Kevin Mourgos ST_MAN 5800 50
Julia Nayer ST_CLERK 3200 50
Irene Mikkilineni ST_CLERK 2700 50
James Landry ST_CLERK 2400 50
Steven Markle ST_CLERK 2200 50
Laura Bissot ST_CLERK 3300 50
Mozhe Atkinson ST_CLERK 2800 50
James Marlow ST_CLERK 2500 50
TJ Olson ST_CLERK 2100 50
Jason Mallin ST_CLERK 3300 50
Michael Rogers ST_CLERK 2900 50
Ki Gee ST_CLERK 2400 50
Hazel Philtanker ST_CLERK 2200 50
Renske Ladwig ST_CLERK 3600 50
Stephen Stiles ST_CLERK 3200 50
John Seo ST_CLERK 2700 50
Joshua Patel ST_CLERK 2500 50
Trenna Rajs ST_CLERK 3500 50
Curtis Davies ST_CLERK 3100 50
Randall Matos ST_CLERK 2600 50
Peter Vargas ST_CLERK 2500 50
Winston Taylor SH_CLERK 3200 50
Jean Fleaur SH_CLERK 3100 50
Martha Sullivan SH_CLERK 2500 50
Girard Geoni SH_CLERK 2800 50
Nandita Sarchand SH_CLERK 4200 50
Alexis Bull SH_CLERK 4100 50
Julia Dellinger SH_CLERK 3400 50
Anthony Cabrio SH_CLERK 3000 50
Kelly Chung SH_CLERK 3800 50
Jennifer Dilly SH_CLERK 3600 50
Timothy Gates SH_CLERK 2900 50
Randall Perkins SH_CLERK 2500 50
Sarah Bell SH_CLERK 4000 50
Britney Everett SH_CLERK 3900 50
Samuel McCain SH_CLERK 3200 50
Vance Jones SH_CLERK 2800 50
Alana Walsh SH_CLERK 3100 50
Kevin Feeney SH_CLERK 3000 50
Donald OConnell SH_CLERK 2600 50
Douglas Grant SH_CLERK 2600 50
Alexander Hunold IT_PROG 9000 60
Bruce Ernst IT_PROG 6000 60
David Austin IT_PROG 4800 60
Valli Pataballa IT_PROG 4800 60
Diana Lorentz IT_PROG 4200 60
Hermann Baer PR_REP 10000 70
John Russell SA_MAN 14000 80
Karen Partners SA_MAN 13500 80
Alberto Errazuriz SA_MAN 12000 80
Gerald Cambrault SA_MAN 11000 80
Eleni Zlotkey SA_MAN 10500 80
Steven King AD_PRES 24000 90
Neena Kochhar AD_VP 17000 90
Lex De Haan AD_VP 17000 90
Nancy Greenberg FI_MGR 12000 100
Daniel Faviet FI_ACCOUNT 9000 100
John Chen FI_ACCOUNT 8200 100
Ismael Sciarra FI_ACCOUNT 7700 100
Luis Popp FI_ACCOUNT 6900 100
Jose Manuel Urman FI_ACCOUNT 7800 100
Shelley Higgins AC_MGR 12000 110
William Gietz AC_ACCOUNT 8300 110
77 rows selected.
I am not however getting the desired output,as the output is not displaying this row:
Employee Name JOB_ID SALARY DEPARTMENT_ID
---------------------------------------------- ---------- ---------- -------------
Kimberely Grant SA_REP 7000
此记录没有部门编号，但也应与其他77行一起显示在输出中。任何人都可以指出我的查询出错了吗？
答案 0 :(得分：0)
所以我们的目标是获得除销售代表和80部门以外的所有员工的清单？也就是说，你仍然希望部门80（以及所有其他部门）的员工除非他们是销售代表和销售代表，除非他们在部门80？
在Oracle中，NULL值与其他任何值的比较都会返回NULL而不是TRUE或FALSE。因此，您需要：（a）添加明确的IS NULL条件（或IS NOT NULL，具体取决于您的查询参数）或（b）使用COALESCE()（或{{1功能。像这样：
NVL()或：
SELECT first_name || ' ' || last_name "Employee Name"
, job_id, salary, department_id
FROM employees
WHERE job_id != 'SA_REP'
OR department_id IS NULL
OR department_id != 80
ORDER BY department_id;
答案 1 :(得分：0)
感谢@DavidFaber确认我最初的想法。你在where子句中的不是没有与department_id = 80部分一起玩，因为在department_id中Kimbereley Grant的空值。基本上，＆＃34;不是（job_id =＆＃39; SA_REP＆＃39;和department_id = 80）＆＃34;变成＆＃34;而不是job_id =＆＃39; SA_REP＆＃39;或者不是department_id = 80＆＃34;，因此＆＃34; job_id！=＆＃39; SA_REP＆＃39;或department_id！= 80＆＃34;。
Kimberely Grant未通过第一次检查（她的job_id实际上是SA_REP），第二次检查应该基本上导致＆＃34;未知＆＃34; （她的department_id不是80，但它也不是80，它是NULL）。结果，你有假或＆＃34;未知＆＃34;这变得虚假。
修复是@Ponder建议的。在department_id上添加空检查：
not（job_id =＆＃39; SA_REP＆＃39; and department_id = 80且department_id不为空）
相当于：
not（job_id =＆＃39; SA_REP＆＃39; and department_id = 80）或department_id为空
答案 2 :(得分：0)
谢谢大家。我现在可以使用此查询获得所需的输出：
SELECT first_name || ''|| last_name“员工姓名” ，job_id，salary，department_id 来自员工 WHERE job_id！='SA_REP' OR department_id是NULL OR department_id！= 80 ORDER BY department_id;
非常感谢。谢谢。