When creating the foreign key I came across this error. Below is my code.
create table tblPerson(
ID int not null primary key,
Fullname varchar(50) not null,
Email varchar(50) not null,
GenderId int
)
create table tblGender (
ID int not null primary key,
Gender varchar(50) not null
)
alter table tblPerson add constraint tblPerson_GenderId_FK
foreign key (GenderId) references tblGender(ID)
You want to identify any "do not align" rows....
I have made the below.
You won't be able to add the FK constraint, if any rows come back from the SELECT query.
I have also removed the hungarian notation for "tbl". I would advise against it.
create table dbo.Person(
ID int not null primary key,
Fullname varchar(50) not null,
Email varchar(50) not null,
GenderId int )
create table dbo.Gender (
ID int not null primary key,
Gender varchar(50) not null
)
/* any rows below? your FK creation will fail */
Select *, p.GenderId as 'HoustonWeHaveAProblemValue' from dbo.Person p Where Not Exists (Select 1 from dbo.Gender g where g.ID = p.GenderId)
alter table dbo.Person add constraint Person_GenderId_FK
foreign key (GenderId) references dbo.Gender(ID)
Hi please use the following code to achieve your goal :
1-First create tblGender:
create table tblGender (
ID int not null primary key,
Gender varchar(50) not null
)
2-Then create table tblPerson with the relationship between 2 tables since the beginning:
create table tblPerson(
ID int not null primary key,
Fullname varchar(50) not null,
Email varchar(50) not null,
GenderId int references tblGender(ID)
)
works fine.
Related
The three tables are as follows:
CREATE TABLE Artist
(
ArtistKey char(20) NOT NULL PRIMARY KEY,
ArtistName varchar(50) NOT NULL
)
CREATE TABLE AlbumInfo
(
AlbumInfoKey char(20) NOT NULL PRIMARY KEY,
AlbumTitle varchar(50) NOT NULL,
AlbumDate date NULL,
AlbumStudio varchar(50) NULL
)
CREATE TABLE AlbumArtist
(
AlbumInfoKey char(20) NOT NULL,
ArtistKey char(20) NOT NULL,
PRIMARY KEY CLUSTERED
(
AlbumInfoKey ASC,
ArtistKey ASC
))
My objective is to list all of the artists and their albums. I can't seem to get anything to work.
I have tried:
SELECT
Artist.ArtistName,
AlbumInfo.AlbumTitle
FROM Artist
JOIN AlbumArtist
ON Artist.ArtistKey = AlbumArtist.ArtistKey
JOIN AlbumInfo
On AlbumInfo.AlbumInfoKey = AlbumArtist.AlbumInfoKey
However this gives me back nothing not even an error.
Alright, I had to re-do your whole task, and I have come up with more professional, and better way of managing database. You need to drop those tables, and re-do whole thing like show in code below :
--First create Artist table
CREATE TABLE Artist
(
Artist_key int PRIMARY KEY IDENTITY(1,1),
ArtistName varchar(50) NOT NULL,
);
--Then create Album table
CREATE TABLE AlbumInfo
(
Album_key int NOT NULL PRIMARY KEY IDENTITY(1,1),
AlbumTitle varchar(50) NOT NULL,
AlbumDate date NULL,
AlbumStudio varchar(50) NULL,
Artist_key int FOREIGN KEY (Artist_key) REFERENCES Artist(Artist_key)
);
-- Must have Artist data before referencing in the album table
INSERT into Artist (ArtistName) values ('John')
INSERT into AlbumInfo (AlbumTitle,AlbumDate,AlbumStudio,Artist_key) values ('ABC3','2020-6-12','Def3',(select Artist_key from Artist where Artist_key = 1 ))
--test if data has been inserted
SELECT * FROM Artist
SELECT * FROM AlbumInfo
-- And finally this query will show the Artist with their relevant Albums
SELECT ArtistName,af.AlbumTitle,AlbumStudio from Artist a join AlbumInfo af on af.Artist_key = a.Artist_key
And the result is :
On a database I have the following tables:
create table dbo.Stores (
Id int not null
Name nvarchar (120) not null
)
create table dbo.Users (
Id int not null
Name nvarchar (120) not null
)
Each User or Shop can have:
1 - One physical address;
2 - One website or social media addresses.
Should I have tables for Addresses and Social Media. For example:
create table dbo.Addresses (
Id int not null
Street nvarchar (120) not null,
PostalCode nvarchar (12) not null
City nvarchar (40) not null,
Latitude float null,
Longitude float null
)
create table dbo.UserAddresses (
UserId int not null,
AddressId int not null
)
And the same for Social Media, phone numbers and so on ...
Should I just add Columns to the Users table?
Update 1
For website addresses and social media addresses I am considering having the following:
create table dbo.UserWebAddresses (
UserId int not null,
WebAddressTypeId int not null,
Value nvarchar(200) not null
)
create table dbo.WebAddressTypes (
Id int not null,
Name nvarchar(20) not null
)
Does this make sense?
Add those columns directly to dbo.Stores and dbo.Users if there are no duplicated rows. If they might be duplicated, then create a new table and use FKs.
CREATE TABLE dbo.Stores
(
Id INT NOT NULL IDENTITY(1, 1) PRIMARY KEY,
Name NVARCHAR(120) NOT NULL,
Address_Id INT NULL
);
CREATE TABLE dbo.Users
(
Id INT NOT NULL IDENTITY(1, 1) PRIMARY KEY,
Name NVARCHAR(120) NOT NULL,
Address_Id INT NULL
);
CREATE TABLE dbo.Addresses
(
Id INT NOT NULL IDENTITY(1, 1) PRIMARY KEY,
Street NVARCHAR(120) NOT NULL,
PostalCode NVARCHAR(12) NOT NULL,
City NVARCHAR(40) NOT NULL,
Latitude FLOAT NULL,
Longitude FLOAT NULL
);
ALTER TABLE dbo.Stores
ADD CONSTRAINT Stores_Address_Id_FK FOREIGN KEY (Address_Id) REFERENCES dbo.Addresses(Id);
ALTER TABLE dbo.Users
ADD CONSTRAINT Users_Address_Id_FK FOREIGN KEY (Address_Id) REFERENCES dbo.Addresses(Id);
We can also go with the following solution as well if I understood everything correct:
CREATE TABLE dbo.Stores
(
Id INT NOT NULL IDENTITY(1, 1) PRIMARY KEY,
Name NVARCHAR(120) NOT NULL,
Address_Id INT NULL,
Latitude FLOAT NULL,
Longitude FLOAT NULL
);
CREATE TABLE dbo.Users
(
Id INT NOT NULL IDENTITY(1, 1) PRIMARY KEY,
Name NVARCHAR(120) NOT NULL,
Address_Id INT NULL,
Latitude FLOAT NULL,
Longitude FLOAT NULL
);
CREATE TABLE dbo.Addresses
(
Id INT NOT NULL IDENTITY(1, 1) PRIMARY KEY,
Street NVARCHAR(120) NOT NULL,
PostalCode NVARCHAR(12) NOT NULL,
City NVARCHAR(40) NOT NULL
);
ALTER TABLE dbo.Stores
ADD CONSTRAINT Stores_Address_Id_FK FOREIGN KEY (Address_Id) REFERENCES dbo.Addresses(Id);
ALTER TABLE dbo.Users
ADD CONSTRAINT Users_Address_Id_FK FOREIGN KEY (Address_Id) REFERENCES dbo.Addresses(Id);
Here is my code it generates Foreign key conflict error
CREATE TABLE tblProducts
(
ProductID int NOT NULL IDENTITY PRIMARY KEY,
ProductName nvarchar(30) NOT NULL,
BatchID int NOT NULL FOREIGN KEY REFERENCES tblBatches (BatchID)
)
CREATE TABLE tblBatches
(
BatchID INT NOT NULL IDENTITY PRIMARY KEY,
BatchCode nvarchar(20) NOT NULL,
Quantity int NOT NULL,
BatchMnf Date NOT NULL,
BatchExp Date NOT NULL,
PurchaseRate int NOT NULL,
SalesRate int NOT NULL,
ProductID int NOT NULL FOREIGN KEY REFERENCES tblProducts (ProductID)
)
You cannot do that. This is a circular reference.
This is a bad design but if you want to do that, you need to make foreign key columns Nullable.
CREATE TABLE tblProducts
(
ProductID int NOT NULL IDENTITY PRIMARY KEY,
ProductName nvarchar(30) NOT NULL,
BatchID int NULL FOREIGN KEY REFERENCES tblBatches (BatchID)
)
CREATE TABLE tblBatches
(
BatchID INT NOT NULL IDENTITY PRIMARY KEY,
BatchCode nvarchar(20) NOT NULL,
Quantity int NOT NULL,
BatchMnf Date NOT NULL,
BatchExp Date NOT NULL,
PurchaseRate int NOT NULL,
SalesRate int NOT NULL,
ProductID int NULL FOREIGN KEY REFERENCES tblProducts (ProductID)
)
Then you need to update reference fields after inserting records in tblBatches and tblProducts.
The good design says you need to create a bridge table like this:
CREATE TABLE tblProductsBatch
(
ID int NOT NULL IDENTITY PRIMARY KEY,
ProductID int NOT NULL,
BatchID int NOT NULL
)
And after inserting product and batch, you need to insert a record in this table to link rows to each other.
CREATE TABLE Schedule
(
Section DATETIME NOT NULL PRIMARY KEY(CourseID, Section, EmployeeID),
CourseID VARCHAR(10) REFERENCES Course(CourseID) NOT NULL,
EmployeeID VARCHAR(20) NOT NULL REFERENCES Employee(EmployeeID),
StartTime TIME NULL,
Days DATE NULL,
Length TIME NULL
)
CREATE TABLE Enrollment
(
StudentID INT Primary key (StudentID, CourseID, Section) NOT NULL,
CourseID VARCHAR(10) REFERENCES Course(CourseID) NOT NULL,
Section DATETIME NOT NULL REFERENCES Schedule(Section)
)
2nd table did not get created, where did I go wrong?
Its because you made the primary key in the Schedule table a natural/combined key.
Try creating a stand alone column for this purpose instead. I've included an example below that shows the differences.
CREATE TABLE DBO.PK_TEST (
Col_A INT NOT NULL
,Col_B INT NOT NULL
,Primary Key(Col_A,Col_B)
)
Create table DBO.PK_TEST_2 (
Col_A int NOT NULL
,Col_B int NOT NULL
,Col_C as (cast(Col_A as nvarchar)
+ cast(Col_B as nvarchar)) PERSISTED NOT NULL
,primary key(Col_C)
)
I Going To Create A DataBase in SQL Server 2014 But I Have Problem .
A Need Use This Option : When The User Want To Register , Select Country , City Of The Country Display And Select it .
For Example : When User Select The U.S.A , Display (NewYourk , Washington , . . . )
Pic Of Prog
CREATE TABLE orders
(
OrderID INT IDENTITY (1,1) NOT NULL PRIMARY KEY,
Fname VARCHAR(50) NOT NULL,
Lname VARCHAR(50) NOT NULL,
Tel VARCHAR(15),
Counts INT NOT NULL,
DaysID INT NOT NULL,
CountryID INT NOT NULL,
CityID INT NOT NULL,
Address VARCHAR(1024) NOT NULL,
FOREIGN KEY (DaysID) REFERENCES WeekDays(DaysID),
FOREIGN KEY (CountryID) REFERENCES Country(ContryID),
FOREIGN KEY (CityID) REFERENCES City(CityID)
)
GO
CREATE TABLE WeekDays
(
DaysID INT IDENTITY (10000001,1) NOT NULL PRIMARY KEY,
DaysName VARCHAR(50) NOT NULL
)
GO
CREATE TABLE Country
(
CountryID INT IDENTITY (2000000,1) NOT NULL PRIMARY KEY,
CountryName VARCHAR(100)
)
CREATE TABLE City
(
CityID INT IDENTITY (2000000,1) NOT NULL PRIMARY KEY,
CityName VARCHAR(100)
)
For that you must have a FOREIGN KEY of CountryID in City table so that you can Fetch the cities of USA
CREATE TABLE City
(
CityID INT IDENTITY (2000000,1) NOT NULL PRIMARY KEY,
CityName VARCHAR(100)
CountryID INT
FOREIGN KEY (CountryID ) REFERENCES Country(CountryID )
)
--FETCH RECORDS
SELECT * FORM City
WHERE CountryID=1 -- OR whatever the id of the Country