Foreign keys

CREATE TABLE Employee(
    EmployeeID int NOT NULL,
    LastName varchar(50) NOT NULL,
    FirstName varchar(20) NOT NULL,
    Age int,
    DeptNo int,
    PRIMARY KEY (EmployeeID),
    FOREIGN KEY (DeptNo) REFERENCES Department(DeptNo)
);

Foreign key

USE Organization
CREATE TABLE Employee_Office
(
Id INT PRIMARY KEY IDENTITY(1,1),
Emp_Id int FOREIGN KEY REFERENCES Employee(Id),
Office_Id int FOREIGN KEY REFERENCES Office(Id)
)

Source: codingsight.com

What is foreign key

Foreign Key: 
It is a column that comes from a different table and
using Foreign key tables are related each other
It is the primary key of another table
It can be duplicate or null for another table

Foreign key

CREATE TABLE Employee(
    EmployeeID int NOT NULL,
    LastName varchar(50) NOT NULL,
    FirstName varchar(20) NOT NULL,
    Age int,
    DeptNo int,
    PRIMARY KEY (EmployeeID),
    FOREIGN KEY (DeptNo) REFERENCES Department(DeptNo)
);

Source: computerscienceai.com

Foreign key

USE Organization
CREATE TABLE Employee
(
Id INT PRIMARY KEY IDENTITY(1,1),
Name VARCHAR (50) NOT NULL,
Age INT,
Gender VARCHAR (50),
Dep_Id int FOREIGN KEY REFERENCES Department(Id),
Insur_Id int FOREIGN KEY REFERENCES Insurance(Id)
)

Source: codingsight.com

Similar codes

0 vote278 views1 answer
Sqlcl format
SQL
-1 vote235 views2 answers
Sql server date format yyyy-MM-ddThh:mm:ss
SQL
0 vote250 views1 answer
Oracle drop default value
SQL
0 vote280 views1 answer
Oracle list datafiles
SQL
0 vote282 views1 answer
Nodejs sql get one to many relationship as array
SQL
0 vote271 views1 answer
How to list function in psql
SQL
0 vote252 views1 answer
Stuff in sql server
SQL
0 vote280 views2 answers
FIND OUT THE NAME HIGHEST SALARY SQL
SQL
1 vote277 views1 answer
Drop column if exists sql server
SQL
0 vote279 views1 answer
Postgres regex word boundary
SQL