sql - 以特定格式获取每个年级的员工人数

Question

我是 sql 新手，我有一张这样的表

Emp_id | Emp_NAME | EMP_GRADE 1 测试1 A1 2 测试2 A2 3 测试3 A3 4 测试4 A4 6 测试5 A1 7 测试6 A2 8 测试7 A3

我需要计算每个年级的员工人数，最终的输出是 “2 - 2 - 2 - 1”在单列中，输出指的是（每个年级的员工人数，即 A1(2) - A2(2)- A3(2) -A4(1)）。任何人都可以为此提供sql查询。我希望我们不需要光标。

Answer 1

SELECT COUNT(Emp_id) FROM myTableName GROUP BY EMP_GRADE

Answer 2

用途：

   DECLARE @Grades varchar(1000)

  SELECT @Grades=coalesce(@Grades + ' ','') +Cast(COUNT(EMP_GRADE) as Varchar(2))+' -'  From TableName 
  Group By EMP_GRADE

  Select @Grades=SUBSTRING(@Grades,0,LEN(@Grades))
  Select @Grades

更新：

SELECT @Grades=coalesce(@Grades + ' ','') +Cast(COUNT(t1.EMP_GRADE) as Varchar(2))+' -'  From @tab1 t
Left Join @tab1 t1 On t1.EMP_GRADE= t.EMP_GRADE And  t1.Emp_id= t.Emp_id 
And t1.EMP_GRADE<>'A3' -- Replace conditions here
Group By t1.EMP_GRADE,t.EMP_GRADE

Answer 3

这应该可行：

SELECT EMP_GRADE, COUNT(EMP_Id) AS EMPS_COUNT
FROM TableName
GROUP BY EMP_GRADE

希望对您有所帮助。继续学习 SQL。

Answer 4

SELECT STUFF((
  SELECT ' - ' + CAST(COUNT(1) AS VARCHAR(max)) 
  FROM myTable 
  GROUP BY EMP_GRADE 
  ORDER BY EMP_GRADE 
  FOR XML PATH('')
), 1, 3, '')

SQL Fiddle example

---

如果您正在过滤，但仍想返回每个成绩的结果，则需要自加入才能获得完整的成绩列表。这是一种方法：

;WITH g AS (SELECT DISTINCT EMP_GRADE FROM myTable)
SELECT STUFF((
  SELECT ' - ' + CAST(COUNT(t.Emp_id) AS VARCHAR(max)) 
  FROM g
  LEFT OUTER JOIN myTable t ON g.EMP_GRADE = t.EMP_GRADE
      AND t.Emp_id % 2 = 1 --put your filter conditions here as part of the join
  GROUP BY g.EMP_GRADE
  ORDER BY g.EMP_GRADE
  FOR XML PATH('')
), 1, 3, '')

SQL Fiddle example