I store data about basketball teams in my Teams table that looks like this:
CREATE TABLE Teams (
Id varchar(5) NOT NULL PRIMARY KEY,
TeamName varchar(50) NOT NULL
);
And I keep team members in TeamMembers table that looks like this:
CREATE TABLE TeamMembers (
Id int NOT NULL PRIMARY KEY,
TeamId VARCHAR(5) FOREIGN KEY REFERENCES Teams(Id),
LastName varchar(50) NOT NULL,
FirstName varchar(50) NOT NULL,
PositionId int NOT NULL
);
Positions are in another table with INT ID's. For example, Guard: 1, Center: 2 and Power Forward: 3 in this exercise.
I want to get a list of basketball teams with NO power forward.
Something like:
select *
from Teams
where Id not in
(
select TeamId
from TeamMembers
where PositionID = 4
)
When checking if a row doesn't exist, use a NOT EXISTS!.
SELECT
T.*
FROM
Teams AS T
WHERE
NOT EXISTS (
SELECT
'team has no power forward member'
FROM
TeamMembers AS M
WHERE
M.TeamID = T.ID AND
M.PositionID = 3) -- 3: Power Forward
Related
I have a table such as:
Create Table SalesTable
( StuffID int identity not null,
County geography not null,
SaleAmount decimal(12,8) not null,
SaleTime datetime not null )
It has a recording of every sale with amount, time, and a geography of the county that the sale happened in.
I want to run a query like this:
Select sum(SaleAmount), County from SalesTable group by County
But if I try to do that, I get:
The type "geography" is not comparable. It cannot be used in the GROUP BY clause.
But I'd like to know how many sales happened per county. Annoyingly, if I had the counties abbreviated (SDC,LAC,SIC, etc) then I could group them because it would simply be a varchar. But then I use the geography datatype for other reasons.
There's a function to work with geography type as char
try this
Select sum(SaleAmount), County.STAsText() from SalesTable
group by County.STAsText()
I would propose a slightly different structure:
create table dbo.County (
CountyID int identity not null
constraint [PK_County] primary key clustered (CountyID),
Name varchar(200) not null,
Abbreviation varchar(10) not null,
geo geography not null
);
Create Table SalesTable
(
StuffID int identity not null,
CountyID int not null
constraint FK_Sales_County foreign key (CountyID)
references dbo.County (CountyID),
SaleAmount decimal(12,8) not null,
SaleTime datetime not null
);
From there, your aggregate looks something like:
Select c.Abbreviation, sum(SaleAmount)
from SalesTable as s
join dbo.County as c
on s.CountyID = c.CountyID
group by c.Abbreviation;
If you really need the geography column in the aggregate, you're a sub-query or a common table expression away:
with s as (
Select c.CountyID, c.Abbreviation,
sum(s.SaleAmount) as [TotalSalesAmount]
from SalesTable as s
join dbo.County as c
on s.CountyID = c.CountyID
group by c.Abbreviation
)
select s.Abbreviation, s.geo, s.TotalSalesAmount
from s
join dbo.County as c
on s.CountyID = s.CountyID;
Note: Using Sql Azure & Entity Framework 6
Say I have the following table of a store's invoices (there are multiple stores in the DB)...
CREATE TABLE [dbo].[Invoice] (
[InvoiceId] INTEGER NOT NULL,
[StoreId] UNIQUEIDENTIFIER NOT NULL,
CONSTRAINT [PK_Invoice] PRIMARY KEY CLUSTERED ([InvoiceId] ASC, [StoreId] ASC)
);
Ideally, I would like the InvoiceId to increment consecutively for each StoreId rather than independent of each store...
InvoiceId | StoreId
-------------------
1 | 'A'
2 | 'A'
3 | 'A'
1 | 'B'
2 | 'B'
Question: What is the best way to get the [InvoiceId] to increment based on the [StoreId]?
Possible options:
a) Ideally a [InvoiceId] INTEGER NOT NULL IDENTITY_BASED_ON([StoreId]) parameter of some kind would be really helpful, but I doubt this exists...
b) A way to set the default from the return of a function based on another column? (AFAIK, you can't reference another column in a default)
CREATE FUNCTION [dbo].[NextInvoiceId]
(
#storeId UNIQUEIDENTIFIER
)
RETURNS INT
AS
BEGIN
DECLARE #nextId INT;
SELECT #nextId = MAX([InvoiceId])+1 FROM [Invoice] WHERE [StoreId] = #storeId;
IF (#nextId IS NULL)
RETURN 1;
RETURN #nextId;
END
CREATE TABLE [dbo].[Invoice] (
[InvoiceId] INTEGER NOT NULL DEFAULT NextInvoiceId([StoreId]),
[StoreId] UNIQUEIDENTIFIER NOT NULL,
CONSTRAINT [PK_Invoice] PRIMARY KEY CLUSTERED ([InvoiceId] ASC, [StoreId] ASC)
);
c) A way to handle this in Entity Framework (code first w/o migration) using DbContext.SaveChangesAsync override or by setting a custom insert query?
Note: I realize I could do it with a stored procedure to insert the invoice, but I'd prefer avoid that unless its the only option.
You should stick to an auto-incrementing integer primary key, this is much simpler than dealing with a composite primary key especially when relating things back to an Invoice.
In order to generate an InvoiceNumber for the sake of a user, which increments per-store, you can use a ROW_NUMBER function partitioned by StoreId and ordered by your auto-incrementing primary key.
This is demonstrated with the example below:
WITH TestData(InvoiceId, StoreId) AS
(
SELECT 1,'A'
UNION SELECT 2,'A'
UNION SELECT 3,'A'
UNION SELECT 4,'B'
UNION SELECT 5,'B'
)
Select InvoiceId,
StoreId,
ROW_NUMBER() OVER(PARTITION BY StoreId ORDER BY InvoiceId) AS InvoiceNumber
FROM TestData
Result:
InvoiceId | StoreId | InvoiceNumber
1 | A | 1
2 | A | 2
3 | A | 3
4 | B | 1
5 | B | 2
After playing around with the answer provided by #Jamiec in my solution I instead decided to go the TRIGGER route in order to persist the invoice number and better work with Entity Framework. Additionally, since ROW_NUMBER doesn't work in an INSERT (AFAIK) I am instead using MAX([InvoiceNumber])+1.
CREATE TABLE [dbo].[Invoice] (
[InvoiceId] INTEGER NOT NULL,
[StoreId] UNIQUEIDENTIFIER NOT NULL,
[InvoiceNumber] INTEGER NOT NULL,
CONSTRAINT [PK_Invoice] PRIMARY KEY CLUSTERED ([InvoiceId] ASC)
);
CREATE TRIGGER TGR_InvoiceNumber
ON [Invoice]
INSTEAD OF INSERT
AS
BEGIN
INSERT INTO [Invoice] ([InvoiceId], [StoreId], [InvoiceNumber])
SELECT [InvoiceId],
[StoreId],
ISNULL((SELECT MAX([InvoiceNumber]) + 1 FROM [Invoice] AS inv2 WHERE inv2.[StoreId] = inv1.[StoreId]), 1)
FROM inserted as inv1;
END;
This allows me to set up my EF class like:
public class Invoice
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int InvoiceId { get; set; }
public Guid StoreId { get; set; }
[DatabaseGenerated(DatabaseGeneratedOption.Computed)]
public int InvoiceNumber { get; set; }
}
I have an existing Stored procedure which has lots of hard-coding with IF conditions. The procedure checks the values of following input fields and displays relevant message: The fields are:
• BrandId
• ProductId
• SchemeId
• RegionId
The existing Message table:
MsgId MsgText
1 AAAA
2 BBBB
3 CCCC
4 MMMM
Existing stored proc. pseudo code:
IF(BrandId in (5,10))
IF(#ProductId in (5))
SELECT ‘BBBB’ as MsgText
END IF
END IF
IF(SchemeId in (1,5,10))
SELECT ‘AAAA’ as MsgText
IF(SchemeId =2 AND #RegionId=4)
SELECT ‘BBBB’ as MsgText
IF (#RegionId=6)
SELECT ‘MMMM’ as MsgText
In order to remove hard-coding and re-writing the procedure cleanly from scratch, I want to design new tables which will store "MsgId"s against a BrandId/ProdId/PlanId/SchemeId value or against a combination of these fields (e.g SchemeId =2 AND RegionId=4).With this kind of design I can directly fetch the relevant MsgId against a specific field or combination of fields.
Could anybody suggest table designs to meet the requirement?
Based on your responses to the comments, this might work out.
create table dbo.[Messages] (
MessageId int not null
, MessageText nvarchar(1024) not null
, constraint pk_Messages primary key clustered (MessageId)
);
insert into dbo.[Messages] (MessageId,MessageText) values
(1,'AAAA')
, (2,'BBBB')
, (13,'MMMM');
create table dbo.Messages_BrandProduct (
BrandId int not null
, ProductId int not null
, MessageId int not null
, constraint pk_Messages_BrandProduct primary key clustered
(BrandId, ProductId, MessageId)
);
insert into dbo.Messages_BrandProduct (BrandId, ProductId, MessageId) values
(5,5,2)
,(10,5,2);
create table dbo.Messages_SchemeRegion (
SchemeId int not null
, RegionId int not null
, MessageId int not null
, constraint pk_Messages_SchemeRegion primary key clustered
(SchemeId, RegionId, MessageId)
);
insert into dbo.Messages_SchemeRegion (SchemeId, RegionId, MessageId)
select SchemeId = 1, RegionId , MessageId = 1 from dbo.Regions
union all
select SchemeId = 5, RegionId , MessageId = 1 from dbo.Regions
union all
select SchemeId = 10, RegionId , MessageId = 1 from dbo.Regions
union all
select SchemeId = 2, RegionId = 4, MessageId = 2
union all
select SchemeId , RegionId = 6, MessageId = 13 from dbo.Schemes;
In your procedure you could pull the messages like this:
select MessageId
from dbo.Messages_BrandProduct mbp
inner join dbo.[Messages] m on mbp.MessageId=m.MessageId
where mbp.BrandId = #BrandId and mbp.ProductId = #ProductId
union -- union all if you don't need to deduplicate messages
select MessageId
from dbo.Messages_SchemeRegion msr
inner join dbo.[Messages] m on msr.MessageId=m.MessageId
where msr.SchemeId = #SchemeId and msr.RegionId = #RegionId;
This should do it.
CREATE TABLE [dbo].[IDs](
[BrandID] [int] NOT NULL,
[ProductID] [int] NOT NULL,
[SchemeID] [int] NOT NULL,
[RegionID] [int] NOT NULL,
[MsgID] [int] NOT NULL
)
You can adjust the table and column names as needed. Cheers.
I have 2 tables:
Order (with a identity order id field)
OrderItems (with a foreign key to order id)
In a stored proc, I have a list of orders that I need to duplicate. Is there a good way to do this in a stored proc without a cursor?
Edit:
This is on SQL Server 2008.
A sample spec for the table might be:
CREATE TABLE Order (
OrderID INT IDENTITY(1,1),
CustomerName VARCHAR(100),
CONSTRAINT PK_Order PRIMARY KEY (OrderID)
)
CREATE TABLE OrderItem (
OrderID INT,
LineNumber INT,
Price money,
Notes VARCHAR(100),
CONSTRAINT PK_OrderItem PRIMARY KEY (OrderID, LineNumber),
CONSTRAINT FK_OrderItem_Order FOREIGN KEY (OrderID) REFERENCES Order(OrderID)
)
The stored proc is passed a customerName of 'fred', so its trying to clone all orders where CustomerName = 'fred'.
To give a more concrete example:
Fred happens to have 2 orders:
Order 1 has line numbers 1,2,3
Order 2 has line numbers 1,2,4,6.
If the next identity in the table was 123, then I would want to create:
Order 123 with lines 1,2,3
Order 124 with lines 1,2,4,6
On SQL Server 2008 you can use MERGE and the OUTPUT clause to get the mappings between the original and cloned id values from the insert into Orders then join onto that to clone the OrderItems.
DECLARE #IdMappings TABLE(
New_OrderId INT,
Old_OrderId INT)
;WITH SourceOrders AS
(
SELECT *
FROM Orders
WHERE CustomerName = 'fred'
)
MERGE Orders AS T
USING SourceOrders AS S
ON 0 = 1
WHEN NOT MATCHED THEN
INSERT (CustomerName )
VALUES (CustomerName )
OUTPUT inserted.OrderId,
S.OrderId INTO #IdMappings;
INSERT INTO OrderItems
SELECT New_OrderId,
LineNumber,
Price,
Notes
FROM OrderItems OI
JOIN #IdMappings IDM
ON IDM.Old_OrderId = OI.OrderID
Suppose I have a table with following data:
gameId difficultyLevel numberOfQuestions
--------------------------------------------
1 1 2
1 2 2
1 3 1
In this example the game is configured for 5 questions, but I'm looking for a SQL statement that will work for n number of questions.
What I need is a SQL statement that given a question, displayOrder will return the current difficulty level of question. For example - given a displayOrder of 3, with the table data above, will return 2.
Can anyone advise how the query should look like?
I'd recommend a game table with a 1:m relationship with a question table.
You shouldn't repeat columns in a table - it violates first normal form.
Something like this:
create table if not exists game
(
game_id bigint not null auto_increment,
name varchar(64),
description varchar(64),
primary key (game_id)
);
create table if not exists question
(
question_id bigint not null auto_increment,
text varchar(64),
difficulty int default 1,
game_id bigint,
primary key (question_id) ,
foreign key game_id references game(game_id)
);
select
game.game_id, name, description, question_id, text, difficulty
game left join question
on game.game_id = question.game_id
order by question_id;
things might be easier for you if you change your design as duffymo suggests, but if you must do it that way, here's a query that should do the trick.
SELECT MIN(difficultyLevel) as difficltyLevel
FROM
(
SELECT difficltyLevel, (SELECT sum(numberOfQuestions) FROM yourtable sub WHERE sub.difficultyLevel <= yt.difficultyLevel ) AS questionTotal
FROM yourTable yt
) AS innerSQL
WHERE innerSQL.questionTotal >= #displayOrder