Wie bekomme ich den Status eines aktuellen Mitarbeiters, den Status eines zurückgetretenen Mitarbeiters, den Status eines neuen Mitarbeiters in einem bestimmten Zeitraum?

Question

Ich habe Mitarbeiterstamm Tabelle in dieser Tabelle haben empcode, empname, joindate, resigndate, aber kein Datum für den Eintrag in Master. Wie aktuelle Mitarbeiter zu erhalten, trat keine Mitarbeiter, keine Mitarbeiter in bestimmten Datum Perioden verbunden

für ex:

current employees -200 
resigned employees -25 
joined employees -10 
current status  -200+10=210-25=185 

jeder dieser i in Tabellenformat wollte

Answer 1

Wenn wir einen Kalender haben Tabelle oder Datum Dimension, Abfrage, Ansicht ... etc, wird dies viel einfacher.

/* example Calendar, just Months */ 
create table dbo.Calendar(
    MonthStart date primary key 
    , MonthEnd date 
); 

declare @FromDate date = '20000101'; 
declare @ThruDate date = '20301201'; 

with n as (select n from (values(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) t(n)) 
, d as (
    select DateValue=convert(date,dateadd(month 
     , row_number() over (order by (select 1)) -1, @fromdate)) 
    from   n as deka 
     cross join n as hecto 
     cross join n as kilo 
) 
insert into dbo.Calendar 
    select top (datediff(month, @FromDate, @ThruDate)+1) 
     MonthStart = dateadd(month, datediff(month, 0, DateValue), 0) 
    , MonthEnd  = dateadd(day,-1, dateadd(month, datediff(month, 0, DateValue)+1, 0)) 
    from d 
    order by DateValue; 

---

Abfrage eine

;with cte as (
select 
    c.MonthStart 
    , c.MonthEnd 
    , e.EmpCode 
    , e.JoinDate 
    , e.ResignDate 
from dbo.Calendar as c 
    inner join dbo.EmpMaster as e 
    on c.MonthEnd >= e.JoinDate 
    and c.MonthStart <= e.ResignDate 
) 
select 
    MonthStart 
    , MonthEnd 
    , CurrentEmployees = sum(
      case when JoinDate < MonthStart 
       then 1 else 0 end) 
    , Joined   = sum(
      case when JoinDate >= MonthStart and JoinDate <= MonthEnd 
       then 1 else 0 end) 
    , Resigned   = sum(
      case when ResignDate >= MonthStart and ResignDate <= MonthEnd 
       then 1 else 0 end) 
    , CurrentStatus = sum(
      case when ResignDate > MonthEnd 
       then 1 else 0 end) 
from cte 
group by 
    cte.MonthStart 
    , cte.MonthEnd 
order by cte.MonthStart; 

ohne CTE common table expression und dann sum(case when.. 1 else 0 end)

und unter Verwendung count(case when ... then column else null end) statt:

select 
    MonthStart 
    , MonthEnd 
    , CurrentEmployees = count (
     case when JoinDate < MonthStart 
      then EmpCode else null end) 
    , Joined   = count (
     case when JoinDate >= MonthStart and JoinDate <= MonthEnd 
      then EmpCode else null end) 
    , Resigned   = count (
     case when ResignDate >= MonthStart and ResignDate <= MonthEnd 
      then EmpCode else null end) 
    , CurrentStatus = count (
     case when ResignDate > MonthEnd 
      then EmpCode else null end) 
from (
    select 
    c.MonthStart 
    , c.MonthEnd 
    , e.EmpCode 
    , e.JoinDate 
    , e.ResignDate 
from dbo.Calendar as c 
    inner join dbo.EmpMaster as e 
    on c.MonthEnd >= e.JoinDate 
    and c.MonthStart <= e.ResignDate 
    ) as cte 
group by cte.MonthStart, cte.MonthEnd 
order by cte.MonthStart 

Jeder gibt die gleichen Ergebnisse: http://rextester.com/AEZTL76069

+------------+------------+------------------+--------+----------+---------------+ 
| MonthStart | MonthEnd | CurrentEmployees | Joined | Resigned | CurrentStatus | 
+------------+------------+------------------+--------+----------+---------------+ 
| 2010-01-01 | 2010-01-31 |    0 |  3 |  0 |    3 | 
| 2010-02-01 | 2010-02-28 |    3 |  1 |  0 |    4 | 
| 2010-03-01 | 2010-03-31 |    4 |  2 |  0 |    6 | 
| 2010-04-01 | 2010-04-30 |    6 |  1 |  0 |    7 | 
| 2010-05-01 | 2010-05-31 |    7 |  2 |  0 |    9 | 
| 2010-06-01 | 2010-06-30 |    9 |  1 |  0 |   10 | 
| 2010-07-01 | 2010-07-31 |    10 |  1 |  0 |   11 | 
| 2010-08-01 | 2010-08-31 |    11 |  2 |  0 |   13 | 
| 2010-09-01 | 2010-09-30 |    13 |  6 |  0 |   19 | 
| 2010-10-01 | 2010-10-31 |    19 |  2 |  0 |   21 | 
| 2010-11-01 | 2010-11-30 |    21 |  1 |  0 |   22 | 
| 2010-12-01 | 2010-12-31 |    22 |  0 |  0 |   22 | 
+------------+------------+------------------+--------+----------+---------------+