Question

我卡住了。我有2个表 - 看看图像1 Table columns我想构建查询，它会给我结果 - 它显示在图像2号上。the result of query。

我有2个查询，我想将它们混合起来，从图像2中获取列表。请帮帮我，如何构建查询。

查询号1：SELECT department_name，department_id FROM DEPARTMENTS WHERE department_id介于90和110之间;
查询号2：SELECT last_name，department_id来自员工WHERE department_id介于90和110之间;

Answer 1

<强>查询：

with departments (department_id, department_name) as (
        select  90, 'Executive'  from dual union all
        select 100, 'Finance'    from dual union all
        select 110, 'Accounting' from dual
     ),
     employees (employee_id, last_name, department_id) as (
        select 1003, 'King'     ,  90 from dual union all
        select 1005, 'De Hann'  ,  90 from dual union all
        select 1009, 'Gietz'    , 110 from dual union all
        select 1013, 'Popp'     , 100 from dual union all
        select 1014, 'Chen'     , 100 from dual union all
        select 1015, 'Higgins'  , 110 from dual union all
        select 1029, 'Greenberg', 100 from dual union all
        select 1040, 'Kochar'   ,  90 from dual union all
        select 1043, 'Faviet'   , 100 from dual union all
        select 1045, 'Urman'    , 100 from dual union all
        select 1049, 'Sciarra'  , 100 from dual
     )
     --   end input data;   begin actual query   --
select c_name, department_id from 
  ( select department_name as c_name, department_id, 0 as categ from departments
    union all
    select '    ' || last_name as c_name, department_id, 1 from employees
    order by department_id, categ, c_name
  );

结果：

C_NAME        DEPARTMENT_ID
------------- -------------
Executive                90
    De Hann              90
    King                 90
    Kochar               90
Finance                 100
    Chen                100
    Faviet              100
    Greenberg           100
    Popp                100
    Sciarra             100
    Urman               100
Accounting              110
    Gietz               110
    Higgins             110

你不需要“带...”部分;只需在两个因子子查询之后（在“输入数据”之后）使用从SELECT语句开始的查询。我甚至为你排了各个部门的姓氏;如果不需要，只需从ORDER BY子句中删除“c_name”。

我调用了第一列c_name;你可以把它称为任何你想要的东西，但是当它也包含员工的姓氏时称它为department_name对我来说没有多大意义。要随意调用它，请将SELECT语句从SELECT c_name, department_id更改为SELECT c_name AS whatever, department_id...

Answer 2

SELECT c.last_name,
       d.department_id,
       d.department_name
FROM employee c
JOIN deptartment d ON d.department_id=c.department_id
WHERE d.department_id BETWEEN 90 AN 110

从我的示例表中输出

+-------+----+------------+
| KING  | 10 | ACCOUNTING |
| BLAKE | 30 | SALES      |
| CLARK | 10 | ACCOUNTING |
| JONES | 20 | RESEARCH   |
| SCOTT | 20 | RESEARCH   |
+-------+----+------------+

组合来自不同表的列值

2 个答案: