Question

我有3个表，这些表的内部连接从dbo.Associates到（by associateId）dbo.Relocations到（by relocationId）dbo.Expenses。下表是

-- Microsoft SQL Server 2017

CREATE TABLE Associates(
    AssociateId varchar(150) not null PRIMARY KEY,
    FirstName varchar(150) not null,
    LastName varchar(150) not null
)

INSERT INTO Associates(AssociateId, FirstName, LastName)
VALUES
('1', 'Tom', 'Tom'),
('2', 'Sue', 'Sue')

CREATE TABLE Relocations(
    RelocationId int not null PRIMARY KEY,
    AssociateId varchar(150) FOREIGN KEY REFERENCES Associates(AssociateId),
    StartingLocation varchar(150),
    EndingLocation varchar(150),
    PlanningCenter varchar(150),
    CostCenter varchar(150),
    OpenDate datetime,
    CloseDate datetime,
    LimitedAmount decimal(18,2),
    RelocationTypeId varchar(150)
)

INSERT INTO Relocations(RelocationId, AssociateId, StartingLocation, 
EndingLocation, PlanningCenter, CostCenter,
OpenDate, CloseDate, RelocationTypeId)
VALUES
(1, '2', 'Jacksonville', 'Macon', 'Buffalo', 'A', '2020-10-20', '2020-10-22', 
'Full Relocation'),
(2, '2', 'Los Angelos', 'New York', 'Detroit', 'B', '2020-09-20', null, 'Full 
Relocation'),
(3, '1', 'Washington DC', 'Houston', 'Dalls', 'C', '2020-08-08', '2020-08- 
15', 'Full Relocation'),
(4, '1', 'Lakeland', 'Atlanta', 'Seattle', 'D', '2020-09-12', '2020-09-28', 
'Full Relocation'),
(5, '1', 'San Diego', 'Woodbury', 'Baltimore', 'E', '2020-10-02', '2020-10- 
17', 'Full Relocation')

CREATE TABLE Expenses(
    ExpenseId int not null PRIMARY KEY,
    RelocationId int FOREIGN KEY REFERENCES Relocations(RelocationId),
    ExepnseTypeId varchar(150),
    DateIncurred datetime,
    GLAccountId varchar(150),
    TaxableAmount decimal(18,2),
    VoucherNumber int,
    Amount decimal(18,2),
    ToBeRepaid decimal(18,2),
    ReportableAmount decimal(18,2),
    LastUpdated datetime
)

INSERT INTO Expenses(ExpenseId, RelocationId, ExepnseTypeId, DateIncurred, 
GLAccountId, TaxableAmount, VoucherNumber,
Amount, ToBeRepaid, ReportableAmount, LastUpdated)
VALUES
(1, 1, 'Item 1', '2020-01-15', 1, 30.30, 23, 500.00, 400.00, 600.00, '2020- 
01-15'),
(2, 1, 'Item 1', '2020-01-20', 2, null, 23, 300.00, 0.00, 300.00, '2020-01- 
20'),
(3, 2, 'Item 2', '2020-02-23', 1, null, 23, 0.00, 0.00, 45.45, '2020-02-23'),
(4, 2, 'Item 3', '2020-03-11', 1, 400.00, 33, 75.00, 80.00, 0.00, '2020-03- 
11'),
(5, 3, 'Item 4', '2020-04-12', 2, 123.23, 33, 2000.50, 76.76, 540.54, '2020- 
04-12'),
(6, 3, 'Item 4', '2020-04-23', 2, null, 33, 1500.00, 0.00, 300.21, '2020-04- 
23'),
(7, 4, 'Item 5', '2020-05-03', 1, 40.00, 43, 43.00, 0.00, 43.56, '2020-05- 
03'),
(8, 4, 'Item 6', '2020-10-15', 2, null, 43, 0.00, 50.55, 76.87, '2020-10- 
15'),
(9, 5, 'Item 7', '2020-10-13', 1, 55.00, 43, 0.00, 0.00, 0.00, '2020-10-13'),
(10, 5, 'Item 8', '2020-10-05', 2, null, 53, 400.00, 0.00, 0.00, '2020-10- 
05')
INSERT INTO Expenses(ExpenseId, RelocationId, ExepnseTypeId, DateIncurred, 
GLAccountId, TaxableAmount, VoucherNumber,
Amount, ToBeRepaid, ReportableAmount, LastUpdated)
VALUES
(11, 5, 'Item 1', '2020-05-17', 2, 25, 53, 150.00, 300.00, 700.00, '2020-05- 
17')

最终，我正在尝试生成与此匹配的输出：

 OpenDate    CloseDate    Account   LastName   FirstName   Amount   Item1   Item2   Item3   Item4    Item5   Item6   Item7   Item8  
------------ ------------ --------- ---------- ----------- -------- ------- ------- ------- -------- ------- ------- ------- ------- 
10/20/2020   10/22/2020         1   Sue        Sue            500   500     null    null    null     null    null    null    null   
10/20/2020   10/22/2020         2   Sue        Sue            300   300     null    null    null     null    null    null    null  
9/20/2020    NULL               1   Sue        Sue             75   null    null    75      null     null    null    null    null   
8/8/2020     8/15/2020          2   Tom        Tom         3500.5   null    null    null    3500.5   null    null    null    null   
9/12/2020    9/28/2020          1   Tom        Tom             43   null    null    null    null     43      null    null    null   
9/12/2020    9/28/2020          2   Tom        Tom              0   null    null    null    null     null    null    null    null   
10/2/2020    10/17/2020         1   Tom        Tom              0   null    null    null    null     null    null    null    null   
10/2/2020    10/17/2020         2   Tom        Tom            550   150     null    null    null     null    null    null    400

在下面的查询中，我能够获得每个联营公司搬迁的费用总额，也可以通过GLAccount（费用表中的字段）获得，如下所示：

select 
    OpenDate,
    CloseDate,
    GLAccountId as Account,
    LastName,
    FirstName,
    SUM(t3.Amount) as Amount
from dbo.Associates t1
inner join dbo.Relocations t2
on t1.AssociateId = t2.AssociateId
inner join dbo.Expenses t3
on t2.RelocationId = t3.RelocationId
group by 
OpenDate,
CloseDate,
GLAccountId,
LastName,
FirstName

上面的查询使我获得所需输出的前6个字段。但是我不知道如何获取剩余的Item字段

Answer 1

对于固定的项目列表，可以使用条件聚合：

select 
    r.OpenDate,
    r.CloseDate,
    e.GLAccountId as Account,
    a.LastName,
    a.FirstName,
    sum(e.Amount) as Amount,
    sum(case when e.ExpenseTypeId = 'Item 1' then e.amount end) item1,
    sum(case when e.ExpenseTypeId = 'Item 2' then e.amount end) item2,
    sum(case when e.ExpenseTypeId = 'Item 3' then e.amount end) item3,
    ...
    sum(case when e.ExpenseTypeId = 'Item 8' then e.amount end) item8
from dbo.Associates a
inner join dbo.Relocations r on r.AssociateId = a.AssociateId
inner join dbo.Expenses    e on e.RelocationId = r.RelocationId
group by r.OpenDate, r.CloseDate, e.GLAccountId, a.LastName, a.FirstName

请注意，我使用了有意义的表别名，并使用它们所属的表对所有列名进行了限定。这样可以大大提高查询的可读性，从而提高查询的可维护性。

需要帮助从sql内部联接获取SUM数据

1 个答案: