Question

我正在尝试显示每个办公室有多少员工以及办公室名称，但我无法让它工作。我试过这个

select count(*) as count,office_staff.staff_id
from staff
inner join office_staff on staff.staff_id = office_staff.staff_id
group by staff.staff_id

但我得到的输出是：

# count, staff_id
'1', '1001'
'1', '1002'
'1', '1003'
'1', '1004'
'1', '1005'
'1', '1006'

表

-- -----------------------------------------------------
-- Table `mydb`.`staff`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`staff` (
  `staff_id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
  `office_id` INT(10) UNSIGNED NOT NULL,



-- -----------------------------------------------------
-- Table `mydb`.`office_staff`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`office_staff` (
  `office_staff_id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
  `staff_id` INT(10) UNSIGNED NOT NULL,
  `office_id` INT(10) UNSIGNED NOT NULL,
  `


-- -----------------------------------------------------
-- Table `mydb`.`offices`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`offices` (
  `office_id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
  `address_id` INT(10) UNSIGNED NOT NULL,

任何人都可以帮助我吗？谢谢！

Answer 1

使用office id而不是staff_id

  select count(*) as count, office_staff.office_id
  from staff
  inner join office_staff on staff.staff_id = office_staff.staff_id
  group by office_staff.office_id

Answer 2

我假设您的offices表格中有一列名为Name（您的结构已被切断）。我拉Name的原因是因为这一行：

我正在尝试显示每个办公室有多少员工以及办公室名称

这应该是您需要做的所有事情（根据需要更改列名称）：

Select  O.Name   As OfficeName,
        Count(*) As count
From    staff        S
Join    office_staff OS On S.staff_id = OS.staff_id
Join    office       O  On O.Office_Id = OS.Office_Id
Group By O.Name

Answer 3

尝试：

select count(*) as count,office_id
from staff, office_staff
inner join office_staff on staff.staff_id = office_staff.staff_id
group by office.id

找出每个办公室的员工人数 - Mysql

3 个答案: