Question

下面的查询工作正常并给出结果A，B，C

SELECT winner
FROM nobel_win
WHERE (SUBJECT='Economics' AND Year=1971 );

此外，下面的查询工作正常并给出D，E，F

SELECT winner
FROM nobel_win
WHERE (SUBJECT='Physics' AND Year=1970 );

我想在一个WHERE条件下使它们得到结果A，B，D，E，F但它失败

SELECT winner
FROM nobel_win
WHERE (SUBJECT='Physics' AND Year=1970 )
OR (SUBJECT='Economics' AND Year=1971);

在集合论中，联合会为您提供综合结果。这就是我使用OR的原因。

来源

https://www.w3resource.com/sql-exercises/sql-retrieve-from-table.php#SQLEDITOR

由于

Answer 1

我认为他们的在线查询工具SQLEDITOR包含错误：
https://www.w3resource.com/sql-exercises/sql-retrieve-from-table.php#SQLEDITOR
当我尝试进行OR查询时，出现了一些奇怪的错误：请求存在问题。

如果你在他们的页面上运行REPORT zitab_siddhi. TYPES: BEGIN OF EMPLOYEE, EMPID TYPE C, EMPNAME TYPE string, EMPADDRESS TYPE c, EMPEMAIL TYPE c, EMPDEPT TYPE c, EMPROLE TYPE string, EMPCONT TYPE C, END OF employee. TYPES ITAB_EMPLOYEE TYPE STANDARD TABLE OF EMPLOYEE. DATA: ITAB_EMPLOYEE_I TYPE EMPLOYEE. ITAB_EMPLOYEE_I-EMPID = '123'. ITAB_EMPLOYEE_I-EMPNAME = 'JOHN DOE'. ITAB_EMPLOYEE_I-EMPADDRESS = 'BANGALORE'. ITAB_EMPLOYEE_I-EMPEMAIL = 'JOHN@BANGALORE.COM'. ITAB_EMPLOYEE_I-EMPDEPT = 'SALES'. ITAB_EMPLOYEE_I-EMPROLE = 'MANAGER'. ITAB_EMPLOYEE_I-EMPCONT = '1234567890'. APPEND ITAB_EMPLOYEE_I TO ITAB_EMPLOYEE.，然后将整个结果（整个SELECT * FROM nobel_win表）复制到另一个工具，如SQLFiddle，那么一切都很好，请看下面的演示： http://sqlfiddle.com/#!9/f33d08/3

只是不要使用他们的错误在线工具来学习这些东西，而是使用一些真正的数据库。
如果您更喜欢在线工具，并且不愿意在计算机上安装真实数据库，请使用SQLFiddle或DBFiddle。

nobel_win

SELECT winner
FROM nobel_win
WHERE (SUBJECT='Economics' AND Year=1971 );

|        winner |
|---------------|
| Simon Kuznets |

SELECT winner
FROM nobel_win
WHERE (SUBJECT='Physics' AND Year=1970 );

|        winner |
|---------------|
| Hannes Alfven |
|    Louis Neel |

SQL多个条件

1 个答案: