我正在研究板球项目。我有一个表OverDetails。我想在此表中插入数据。
ID OverNumber BowlerID InningsID
1 1 150 1
2 4 160 1
3 3 165 1
4 2 150 1
Row_1，Row_2和Row_3是合法的。 Row_4不合法，因为一个投球手不能在一局中连续两次投球。没有必要在数据库中连续添加过量。
我在SQL Server中添加了一个约束。
＃Constraint_1
ALTER TABLE OverDetails ADD CONSTRAINT UniqueOverInInning
UNIQUE(OverNumber, BowlerID, IninngsID);
这种约束非常有效。
我需要这样的支票：
＃Constraint_2
ALTER TABLE OverDetails ADD CONSTRAINT UniqueConsecutiveBowlerInOneInning
CHECK (OverNumber + 1 != OverNumber and BowlerID + 1 != BowlerID
and IninngID + 1 != IninngID)
答案 0 :(得分：1)
你需要一个从给定的InningID中返回最后一个BowlerID的函数：
CREATE FUNCTION dbo.GetBowlerID
( @InningId INT, @OverNumber INT, @BowlerID INT)
RETURNS INT
AS
BEGIN
RETURN (SELECT top 1 CASE WHEN
(SELECT BowlerID
FROM OverDetails
WHERE InningsId = @InningId AND OverNumber = @OverNumber - 1 ) = @BowlerID
OR
(SELECT BowlerID
FROM OverDetails
WHERE InningsId = @InningId AND OverNumber = @OverNumber + 1 ) = @BowlerID
THEN 1 else 0 end)
END
然后你可以把它放入检查约束中：
ALTER TABLE OverDetails ADD CONSTRAINT UniqueConsecutiveBowlerInOneInning
CHECK (dbo.GetBowlerID(InningsId, OverNumber, BowlerID)=0)
答案 1 :(得分：1)
检查约束不能直接引用其他行数据。有一些技术试图使用UDF来解决这个限制，但它们往往效果不好。特别是在这种情况下我假设第4行的插入应该也如果它的bowlerID为165则会被阻止，因为这意味着超过2＆3会共用一个投球手。
相反，我们可以使用一对视图来实现它。我通常把DRI放在像这样的视图名称的某个地方，以表明它们是出于声明性参照完整性的原因，而不是因为我打算让人们查询它们。
create table dbo.Bowling (
ID int not null,
OverNumber int not null,
BowlerID int not null,
InningsID int not null,
constraint PK_Bowling PRIMARY KEY (ID),
constraint UQ_Bowling_Overs UNIQUE (OverNumber,InningsID)
)
go
create view dbo.Bowling_DRI_SuccessiveOvers_Odd
with schemabinding
as
select
(OverNumber/2) as OddON,
BowlerID
from
dbo.Bowling
go
create unique clustered index UQ_Bowling_DRI_SuccessiveOvers_Odd on dbo.Bowling_DRI_SuccessiveOvers_Odd (OddON,BowlerID)
go
create view dbo.Bowling_DRI_SuccessiveOvers_Even
with schemabinding
as
select
((OverNumber+1)/2) as EvenON,
BowlerID
from
dbo.Bowling
go
create unique clustered index UQ_Bowling_DRI_SuccessiveOvers_Even on dbo.Bowling_DRI_SuccessiveOvers_Even (EvenON,BowlerID)
go
insert into dbo.Bowling(ID,OverNumber,BowlerID,InningsID) values
(1,1,150,1),
(2,4,160,1),
(3,3,165,1)
go
insert into dbo.Bowling(ID,OverNumber,BowlerID,InningsID) values
(4,2,150,1)
此最终插入会生成错误：
消息2601，级别14，状态1，行37无法插入重复的键行 在对象＆＃d ;.Bowling_DRI_SuccessiveOvers_Even＆＃39;具有独特的索引 ＆＃39; UQ_Bowling_DRI_SuccessiveOvers_Even＆＃39 ;.重复键值为（1， 150）。声明已经终止。
希望你可以看到我用来制作这些视图的技巧来检查你想要的约束 - 它的设置是为了让行与它们配对（逻辑，基于OrderNumber ）继承者或前任者基于使用整数数学将OrderNumber除以2。
然后，我们对这些对应用唯一约束，包括BowlerID。只有当相同的投球手连续两次投球时，我们才会生成多个具有相同（OddON / EvenON）和BowlerID值的行。
答案 2 :(得分：0)
也许这个？
workbook=new HSSFWorkbook();
HSSFSheet Sheet=workbook.createSheet("List Order Details");
Row rowHeading=Sheet.createRow(0);
rowHeading.createCell(0).setCellValue("Invoice ID");
rowHeading.createCell(1).setCellValue("Food Court Name");
rowHeading.createCell(2).setCellValue("Food Stall Name");
rowHeading.createCell(3).setCellValue("Customer Name");
rowHeading.createCell(4).setCellValue("Total Price");
rowHeading.createCell(5).setCellValue("order status");
rowHeading.createCell(6).setCellValue("Delivery Location");
rowHeading.createCell(7).setCellValue("Delivery Date");
rowHeading.createCell(8).setCellValue("Delivery Time");
for(int i=0;i<9;i++){
CellStyle stylerrowHeading=workbook.createCellStyle();
HSSFFont font=workbook.createFont();
font.setBold(true);
font.setFontName(HSSFFont.FONT_ARIAL);
font.setFontHeightInPoints((short)11);
stylerrowHeading.setFont(font);
stylerrowHeading.setVerticalAlignment(CellStyle.ALIGN_CENTER);
rowHeading.getCell(i).setCellStyle( stylerrowHeading);
}
if (null == excelList)
return null;
int r=1;
Row row=Sheet.createRow(r++);
//id coloumn
Cell cellId=(Cell) row.createCell(0);
orderDO.setId(String.valueOf(orderEntity.getId()));
cellId.setCellValue(""+orderEntity.getId());
r++;
//foodstall name
Cell cellStallName=(Cell) row.createCell(2);
cellStallName.setCellValue(foodStallEntity.getName());
r++;
//foodCourtname
Cell cellCourtName=(Cell) row.createCell(1);
cellCourtName.setCellValue(foodCourtEntity.getName());
//customername
Cell cellCustomerName=(Cell) row.createCell(3);
cellCustomerName.setCellValue(customerEntity.getName());
r++;
//total price
Cell cellTotalPrice=(Cell) row.createCell(4);
CellStyle styleprice=workbook.createCellStyle();
HSSFDataFormat cf=workbook.createDataFormat();
styleprice.setDataFormat(cf.getFormat(" $#,##0.00"));
cellTotalPrice.setCellStyle(styleprice);
//orderstatus
Cell cellOrderStatus=(Cell) row.createCell(5);
orderDO.setStatus(OrderStatusDTO.valueOf(orderEntity.getOrderstatus()));
cellOrderStatus.setCellValue(orderEntity.getOrderstatus());
//deliveryLocation
Cell cellBuilding=(Cell) row.createCell(6);
DeliveryLocationEntity deliveryLocationEntity = deliveryLocationRepository
.findById(orderEntity.getDeliverylocationid());
orderDO.setDeliveryBuilding(deliveryLocationEntity.getBuilding());
cellBuilding.setCellValue(deliveryLocationEntity.getBuilding());
//deliverydate
Cell cellDeliveryDate=(Cell) row.createCell(7);
String s1 = String.valueOf(orderEntity.getOrderDate());
orderDO.setOrderDate(s1.substring(0, 10));
cellDeliveryDate.setCellValue(orderEntity.getOrderDate());
CellStyle styleCreationDate=workbook.createCellStyle();
HSSFDataFormat dfCreationDate=workbook.createDataFormat();
styleCreationDate.setDataFormat(dfCreationDate.getFormat(" m/d/yy"));
cellDeliveryDate.setCellStyle(styleCreationDate);
//deliverytime
Cell cellDeliveryTime=(Cell) row.createCell(8);
orderDO.setDeliveryTime(orderEntity.getDeliverytime());
cellDeliveryTime.setCellValue(orderEntity.getDeliverytime());
for(int i=0;i<9;i++)
Sheet.autoSizeColumn(i);
FileOutputStream out=new FileOutputStream(new File("attachment; filename=listproducts.xls"));
//response.setHeader("Content-disposition", "attachment; filename=listproducts.xls");
workbook.write(out);
out.close();
workbook.close();
System.out.println("data enter Sucessfully...");
} catch (Exception e) {
// TODO: handle exception
System.out.println(e.getMessage());
}
return workbook;
}