Question

嗨，这是数据库结构。

employee (employee-name, street, city)
works (employee-name, company-name, salary)
company (company-name, city)
manages (employee-name, manager-name)

我需要获得以下详细信息，但据我的培训师说，错误可以告诉我以下查询中有什么问题吗？

查找所有员工的姓名，街道地址和居住城市谁为First Bank Corporation工作并赚取超过10,000美元。

SELECT e.employee-name, e.city
FROM employee e
INNER JOIN works w
ON e.employee-name = w.employee-name
AND w.company-name = “First Bank Corporation”
GROUP BY e.employee-name
HAVING w.salary > 10000

查找数据库中与公司位于同一城市的所有员工为他们工作。

SELECT e.employee-name
FROM employee e
INNER JOIN works w
ON e.employee-name = w.emploee-name
INNER JOIN company c
ON w.company-name = c.company-name
GROUP BY e.employee-name
HAVING e.city = c.city

查找数据库中所有居住在同一城市和城市的员工与他们的经理一样的街道。

SELECT employee-name, street, city
FROM employee
INTERSECT
SELECT e.employee-name, e.street, e.city
FROM employee e, manages m
WHERE e.employee-name = m.manager-name

Answer 1

要避免语句上出现语法错误，请使用反引号包含包含非文字字符（，如减号，空格，... ）的列名。

First Query，

SELECT  e.`employee-name`, e.city
FROM    employee e
        INNER JOIN works w
            ON e.employee-name = w.employee-name
WHERE   w.`company-name` = 'First Bank Corporation' AND
        w.salary > 10000

其次，

SELECT  e.`employee-name`
FROM    employee e
        INNER JOIN works w
            ON e.`employee-name` = w.`employee-name`
        INNER JOIN company c
            ON w.`company-name` = c.`company-name`
WHERE   e.city = c.city

第三，

SELECT  emp.*
FROM    Manages a
        INNER JOIN employee man
            ON a.`manager-name` = man.`employee-name`
        INNER JOIN employee emp
            ON a.`employee-name` = emp.`employee-name`
WHERE   man.city = emp.city AND
        emp.street = man.street

Answer 2

您应该使用WHERE条款。

查找为First Bank Corporation工作且收入超过10,000美元的所有员工的姓名，街道地址和居住城市。

SELECT e.`employee-name`, e.street, e.city
FROM employee e
INNER JOIN works w ON e.`employee-name` = w.`employee-name`
WHERE w.company-name = "First Bank Corporation"
AND w.salary > 10000

使用WHERE子句而不是GROUP BY和HAVING。

查找数据库中与所在公司位于同一城市的所有员工。

SELECT e.`employee-name`
FROM employee e
INNER JOIN works w ON e.`employee-name` = w.`employee-name`
INNER JOIN company c ON w.`company-name` = c.`company-name`
WHERE e.city = c.city

查找数据库中与其经理一样生活在同一城市和街道上的所有员工。

SELECT m.`employee-name`
FROM manages m
INNER JOIN employee e ON e.`employee-name` = m.`employee-name`
INNER JOIN employee manager ON manager.`employee-name` = m.`manager-name`
WHERE e.street = manager.street
AND e.city = manager.city

Answer 3

您可以使用WHERE而不是GROUP BY和HAVING来解决前两个问题。第一个：

SELECT e.employee-name, e.city
FROM employee e
INNER JOIN works w
ON e.employee-name = w.employee-name
WHERE w.company-name = “First Bank Corporation”
AND w.salary > 10000

第二个：

SELECT e.employee-name
FROM employee e
INNER JOIN works w
ON e.employee-name = w.employee-name
INNER JOIN company c
ON w.company-name = c.company-name
WHERE e.city = c.city

Answer 4

以下是我如何解决第一个问题：

SELECT employee-name, street, city 
FROM employee 
WHERE employee-name = (
SELECT employee-name 
FROM works where company-name = "First Bank Corporation" 
AND salary > 10000)

如果您需要其他人的帮助，请告诉我

员工详细信息无法正常显示

4 个答案: