How do I insert a subquery with multiple results into multiple rows? - sql

I want to add the results of a query into a table. There are multiple values, being inserted into multiple rows that are currently NULLS.
I have the following tables:
CREATE TABLE CAR (
CarID INT NOT NULL PRIMARY KEY,
Make VARCHAR (30) NOT NULL,
Model VARCHAR (30) NOT NULL,
Type VARCHAR (30) NOT NULL,
YearModel INT NOT NULL,
Price VARCHAR (100) NOT NULL,
);
CREATE TABLE [TRANSACTION] (
tID INT NOT NULL PRIMARY KEY,
cID INT NOT NULL FOREIGN KEY REFERENCES CUSTOMER(CID),
CarID INT NOT NULL FOREIGN KEY REFERENCES CAR(CARID),
eID INT NOT NULL FOREIGN KEY REFERENCES EMPLOYEE(EID),
tDate DATE,
PickupDate DATE NOT NULL,
ReturnDate DATE NOT NULL
);
I then had to add a new column:
ALTER TABLE [TRANSACTION]
ADD Amount_Due int;
The following code gives me the results I need:
SELECT Price*DATEDIFF(DAY,PickupDate, ReturnDate)
FROM [TRANSACTION], CAR
WHERE [TRANSACTION].CarID = CAR.CarID
But I don't know how to insert all of the data into my Amount_Due column.
I have tried to use INSERT INTO, but it's telling me I have a syntax error near Amount_Due.
INSERT INTO [TRANSACTION] Amount_Due
SELECT Price*DATEDIFF(DAY,PickupDate, ReturnDate)
FROM CAR, [TRANSACTION]
WHERE CAR.CarID = [TRANSACTION].CarID
I have played around with INSERT INTO and UPDATE and I cannot wrap my head around what I'm doing wrong, or what I am missing.
I'm using SQL SMS 2018
Thank you for any help.

You are not inserting data you are updating existing rows, so you need to update:
update t set
t.Amount_Due = c.Price * DateDiff(day, c.PickupDate, c.ReturnDate)
from [transaction] t
join car c on c.carId=t.carId
Notes
Always use proper join syntax, avoid adding tables separated by
commas.
Also always alias your tables with meaningful short
aliases for readability.
Avoid using reserved words for objects eg
transaction - if your table contains more than 1 row then call it
transactions and avoid the need to always have to use [] to avoid
ambiguity.
SSMS is not SQL Server, SSMS is just an application used to access SQL Server. Use select ##version if you ever need to know your SQL Server version.

Related

Subqueries are not allowed in this context. Only scalar expressions are allowed in CREATE TABLE with AS syntax

I am trying to run the below script but I keep getting the error messages
"Subqueries are not allowed in this context. Only scalar expressions are allowed." on lines 16 and 34.
I know where it's failing - it is failing on the AS clauses, but I don't know how to correct it with different code to stop the errors from appearing.
I have tried looking around at other existing questions but none helped me that I can find. As the issue I have here is using data from columns in different tables along with columns in the current table.
Could I get some help with getting this working and advise what code will be better please?
Thanks for your help in advance!
Dan
This is the code for my database::
CREATE DATABASE [LEARNING]
GO
CREATE TABLE Trainees
(
Trainee_ID int IDENTITY(1,1) PRIMARY KEY NOT NULL,
Name varchar(50) NOT NULL,
[Assigned Tutor_ID] int NOT NULL,
)
GO
CREATE TABLE Tutors
(
Tutor_ID int IDENTITY(1,1) PRIMARY KEY NOT NULL,
Name varchar(50) NOT NULL,
[Assigned Trainee_ID] AS (Select Trainee_ID from Trainees where Tutors.[Assigned Trainee_ID] = Trainees.Trainee_ID) NOT NULL
)
GO
CREATE TABLE [Rooms]
(
Room_ID int IDENTITY(1,1) PRIMARY KEY NOT NULL,
[Room Name] varchar(50) NOT NULL,
[Cost per hour] money NOT NULL
)
GO
CREATE TABLE [Rooms Rented]
(
Rented_ID int IDENTITY(1,1) PRIMARY KEY NOT NULL,
Room_ID int NOT NULL,
Tutor_ID int NOT NULL,
[Length of time in hours] int NOT NULL,
[Total Cost] AS (select ([Rooms Rented].[Length of time in hours])*([Rooms].[Cost per hour]) from [Rooms]) NOT NULL
)
GO
INSERT INTO Tutors values ('Nikki Smith',1)
GO
INSERT INTO Trainees Values ('Tyler Hatherall')
GO
INSERT INTO Rooms values ('Training Room 1',6.50)
GO
INSERT INTO [Rooms Rented] values (1,1,2)
GO
Computed columns are used to ensure columns persisted property within the table itself.
In your case, you need to have another update after you created table, populate the column by the query similar to below query, also, you need to create Foreign Key in the Total Cost column based on what you try to achieve.
UPDATE A
SET A.[Total Cost] = A.[Length of time in hours] * B.[Cost per hour] --add ISNULL to treat NULL if needed
FROM [Rooms Rented] as A
INNER JOIN [Rooms] as B
ON B.Room_ID = A.Room_ID
Your AS statements are computed columns. When your computed columns refer to other tables, you cannot implement this directly. You will have to create scalar functions first.
For example, after creating Rooms, create this function that takes a room id and returns cost per hour:
create function f_get_Rooms_CostPerHour (#Room_ID int)
returns money
as
return (select [Cost per hour] from [Rooms] where [Rooms].Room_ID=#Room_ID)
Now you can use this in your computed column formula. Note that a computed column formula never has a SELECT in it. It also does not have a null/not null specification.
CREATE TABLE [Rooms Rented]
(
Rented_ID int IDENTITY(1,1) PRIMARY KEY NOT NULL,
Room_ID int NOT NULL,
Tutor_ID int NOT NULL,
[Length of time in hours] int NOT NULL,
[Total Cost] AS ([Length of time in hours]*f_get_Rooms_CostPerHour([Room_ID]))
)

How do I select insert into select a table which already has values in the primary key column without adding new rows?

I'm working on a database for my school project in which I have to produce a functional database by normalizing sample tables given to us.
One table I'm having trouble with is itineraries. I produce 3 tables from the normalization which are "Destinations", "Itineraries" and "Itinerary_Destinations".
The code for Destinations is:
create table Destinations
(
DestinationID varchar(5) primary key,
Name varchar(45)
);
The code for Itineraries is:
create table Itineraries
(
ItineraryID varchar(5),
Name varchar(45)
);
The code for the last table is:
create table Itinerary_Destinations
(
DI varchar(5) primary key,
ItineraryID varchar(5) foreign key references Itineraries(ItineraryID),
Itinerary_Name varchar(45),
DestinationID varchar(5) foreign key references Destinations(DestinationID),
Destination_Name varchar(45)
);
Data has already been inserted into all 3 tables with the exception of 'Destination_Name' and 'Itinerary_Name' columns. The code I'm attempting to use is returning as error. The code is shown below.
insert into Itinerary_Destinations (Itinerary_name)
select Name from Itineraries where
Itineraries.ItineraryID = ItineraryID;
The error it returns is
Msg 515, Level 16, State 2, Line 1 Cannot insert the value NULL into
column 'DI', table 'DDDAssignment.dbo.Itinerary_Destinations'; column
does not allow nulls. INSERT fails. The statement has been terminated.
Is there a method to accomplish the task of inserting the Destination_Name and Itinerary_Name without creating new records that require primary keys?
Or should I do it manually?
If you want to modify records which already exist, then you should be using an UPDATE rather than an INSERT:
UPDATE a
SET Itinerary_name = b.Name
FROM Itinerary_Destinations a
INNER JOIN Itinerary_name b
ON a.ItineraryID = b.ItineraryID;
But, if you do have some data which is not already logically associated with the Itinerary_Destinations table, then using an insert is appropriate.
use coalesce funtion in case null it will insert blank string, as your column does not allow null value thats why you got that error in your query
insert into Itinerary_Destinations (Itinerary_name)
select coalesce(Name,' ') from Itineraries where
Itineraries.ItineraryID = ItineraryID;

How can I get this query to print a record that only exists in one table?

I am trying to create a query that will accept a date from the user and display information from two tables based on this date. This works for all of my tests except my last test. My last test, I enter a date that should return a record that only exists in the expmast table and does not exist in the expbycc table. When I enter the date to try and get this record to be returned, it tells me no records have been found. I know this is because in my where, i have an AND that checks if M.ExpNum = C.ExpNUm which isn;t true for this record because it only exists in one table. I can not figure out how to get this query to work. Any help/advice is greatly appreciated. Below is my script, followed by the table structures used for this query, thank you.
Script:
ACCEPT Date PROMPT 'Enter a date:';
SELECT M.ExpNum, EDate, IsCash, StoreCode, CashAmt, CType, CCNum, Amt
FROM ExpMast M, ExpByCc C
WHERE EDate = to_date('&Date','mm-dd-yy')
AND M.ExpNum = C.ExpNum;
Tables:
CREATE TABLE EXPMAST
(ExpNum NUMBER(2,0) NOT NULL PRIMARY KEY,
EDate DATE,
IsCash VARCHAR2(1),
StoreCode VARCHAR2(4),
CONSTRAINT fk_STORE_EXPMAST FOREIGN KEY (StoreCode)
REFERENCES STORE (Code)
);
CREATE TABLE ExpByCC
(ExpNum NUMBER(2,0) NOT NULL,
CType VARCHAR2(1) NOT NULL,
CCNum VARCHAR2(16) NOT NULL,
Amt DECIMAL(5,2),
CONSTRAINT fk_CRCARD_ExpByCC FOREIGN KEY (CType, CCNum)
REFERENCES CRCARD (CType, CCNum),
CONSTRAINT fk_EXPMAST_ExpByCC FOREIGN KEY (ExpNum)
REFERENCES EXPMAST (ExpNum),
CONSTRAINT pk_ExpByCC PRIMARY KEY (ExpNum, CType, CCNum)
);
You need a left outer join. And you can't express an outer join using your implicit join syntax. You want to use explicit joins in the from clause.
A simple rule: NEVER use commas in the from clause.
Now, it is easy:
SELECT M.ExpNum, EDate, IsCash, StoreCode, CashAmt, CType, CCNum, Amt
FROM ExpMast M LEFT OUTER JOIN
ExpByCc C
ON M.ExpNum = C.ExpNum AND
WHERE M.EDate = to_date('&Date','mm-dd-yy') AND
C.ExpNum IS NULL;

Beginner with triggers

Im a beginner in database and i got this difficult auction database project.
Im using SQL Server Management Studio also.
create table user(
name char(10) not null,
lastname char(10) not null
)
create table item(
buyer varchar(10) null,
seller varchar(10) not null,
startprice numeric(5) not null,
description char(22) not null,
start_date datetime not null,
end_date datetime not null,
seller char(10) not null,
item_nummer numeric(9) not null,
constraint fk_user foreign key (buyer) references user (name)
)
Basically what the rule im trying to make here is:
Column buyer has NULL unless the time (start_date and end_date) is over and startprice didnt go up or increased. Then column buyer will get the name from table user who bidded on the item.
The rule is a bid too difficult for me to make, i was thinking to make a trigger, but im not sure..
Your model is incorrect. First you need a table to store the bids. Then when the auction is over, you update the highest one as the winning bid. Proably the best way is to have a job that runs once a minute and finds the winners of any newly closed auctions.
A trigger will not work on the two tables you have because triggers only fire on insert/update or delete. It would not fire because the time is past. Further triggers are an advanced technique and a db beginner should avoid them as you can do horrendous damage with a badly written trigger.
You could have a trigger that works on insert to the bids table, that updates the bid to be the winner and takes that status away from the previous winner. Then you simply stop accepting new bids at the time the auction is over. Your application could show the bidder who is marked as the winner as the elader if the auction is till open and teh winner if it is closed.
There are some initial problems with your schema that need addressed before tackling your question. Here are changes I would make to significantly ease the implementation of the answer:
-- Added brackets around User b/c "user" is a reserved keyword
-- Added INT Identity PK to [User]
CREATE TABLE [user]
(
UserId INT NOT NULL
IDENTITY
PRIMARY KEY
, name CHAR(10) NOT NULL
, lastname CHAR(10) NOT NULL
)
/* changed item_nummer (I'm not sure what a nummer is...) to ItemId int not null identity primary key
Removed duplicate Seller columns and buyer column
Replaced buyer/seller columns with FK references to [User].UserId
Add currentBid to capture current bid
Added CurrentHighBidderId
Added WinningBidderId as computed column
*/
CREATE TABLE item
(
ItemId INT NOT NULL
IDENTITY
PRIMARY KEY
, SellerId INT NOT NULL
FOREIGN KEY REFERENCES [User] ( UserId )
, CurrentHighBidderId INT NULL
FOREIGN KEY REFERENCES [User] ( UserId )
, CurrentBid MONEY NOT NULL
, StartPrice NUMERIC(5) NOT NULL
, Description CHAR(22) NOT NULL
, StartDate DATETIME NOT NULL
, EndDate DATETIME NOT NULL
)
go
ALTER TABLE dbo.item ADD
WinningBidderId AS CASE WHEN EndDate < CURRENT_TIMESTAMP
AND currentBid > StartPrice THEN CurrentHighBidderId ELSE NULL END
GO
With the additional columns a computed column can return the correct information. If you must return the winner's name instead of id, then you could keep the schema above the same, add an additional column to store the user's name, populate it with a trigger and keep the computed column to conditionally show/not show the winner..

How can I insert into tables with relations?

I have only done databases without relations, but now I need to do something more serious and correct.
Here is my database design:
Kunde = Customer
Vare = Product
Ordre = Order (Read: I want to make an order)
VareGruppe = ehm..type? (Read: Car, chair, closet etc.)
VareOrdre = Product_Orders
Here is my SQL (SQLite) schema:
CREATE TABLE Post (
Postnr INTEGER NOT NULL PRIMARY KEY,
Bynavn VARCHAR(50) NOT NULL
);
CREATE TABLE Kunde (
CPR INTEGER NOT NULL PRIMARY KEY,
Navn VARCHAR(50) NOT NULL,
Tlf INTEGER NOT NULL,
Adresse VARCHAR(50) NOT NULL,
Postnr INTEGER NOT NULL
CONSTRAINT fk_postnr_post REFERENCES Post(Postnr)
);
CREATE TABLE Varegruppe (
VGnr INTEGER PRIMARY KEY,
Typenavn VARCHAR(50) NOT NULL
);
CREATE TABLE Vare (
Vnr INTEGER PRIMARY KEY,
Navn VARCHAR(50) NOT NULL,
Pris DEC NOT NULL,
Beholdning INTEGER NOT NULL,
VGnr INTEGER NOT NULL
CONSTRAINT fk_varegruppevgnr_vgnr REFERENCES Varegruppe(VGnr)
);
CREATE TABLE Ordre (
Onr INTEGER PRIMARY KEY,
CPR INTEGER NOT NULL
CONSTRAINT fk_kundecpr_cpr REFERENCES Kunde(CPR),
Dato DATETIME NOT NULL,
SamletPris DEC NOT NULL
);
CREATE TABLE VareOrdre (
VareOrdreID INTEGER PRIMARY KEY,
Onr INTEGER NOT NULL
CONSTRAINT fk_ordrenr_onr REFERENCES Ordre(Onr),
Vnr INTEGER NOT NULL
CONSTRAINT fk_varevnr_vnr REFERENCES Vare(Vnr),
Antal INTEGER NOT NULL
);
It should work correctly.
But I am confused about Product_Orders.
How do I create an order? For example, 2 products using SQL INSERT INTO?
I can get nothing to work.
So far:
Only when I manually insert products and data into Product_Orders and then add that data to Orders = which makes it complete. Or the other way around (create an order in with 1 SQL, then manually inserting products into Product_orders - 1 SQL for each entry)
You should first create an order and then insert products in the table Product_Orders. This is necessary because you need an actual order with an id to associate it with the table Product_Orders.
You always should create a record in the foreign-key table before being able to create one in your current table. That way you should create a "Post", customer, type, product, order and product_order.
Try this ...
first you have to insert a customer
insert into kunde values(1, 'navn', 1, 'adresse', 1)
then you insert a type
insert into VareGruppe values(1, 'Type1')
then you insert a product
insert into vare values(1, 'product1', '10.0', 1, 1)
then you add an order
insert into ordre values(1, 1, '20090101', '10.0')
then you insert a register to the product_orders table
insert into VareOrdre values (1, 1, 1, 1)
I think this is it. :-)
As the primary keys are autoincrement, don't add them to the insert and specify the columns like this
insert into vare(Nav, Pris, Beholdning, VGnr) values('product1', '10.0', 1, 1)
Use Select ##identity to see the onr value
I think you already have the hang of what needs to happen. But what I think you are getting at is how to ensure data integrity.
This is where Transactions become important.
http://www.sqlteam.com/article/introduction-to-transactions
Is it the SalesPrice (I'm guessing that's what SamletPris means) that's causing the issue? I can see that being a problem here. One common design solution is to have 2 tables: Order and OrderLine. The Order is a header table - it will have the foreign key relationship to the Customer table, and any other 'top level' data. The OrderLine table has FK relationships to the Order table and to the Product table, along with quantity, unit price, etc. that are unique to an order's line item. Now, to get the sales price for an order, you sum the (unit price * quantity) of the OrderLine table for that order. Storing the SalesPrice for a whole order is likely to cause big issues down the line.
A note just in case this is MySQL: If you're using MyISAM, the MySQL server ignores the foreign keys completely. You have to set the engine to InnoDB if you want any kind of integrity actually enforced on the database end instead of just in your logic. This isn't your question but it is something to be aware of.
fbinder got the question right :)