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 vote233 views1 answer
Duplicate table: 7 ERROR: relation "migrations" already exists (SQL: create table "migrations" ("id" serial primary key not null, "migration" varchar(255) not null, "batch" integer not null))
SQL
14 votes150 views2 answers
Oracle export trigger ddl
SQL
0 vote146 views1 answer
MySql get primary keys of table
SQL
-1 vote146 views2 answers
REMOVE DATE FROM DATE TIME SQL SERVER
SQL
0 vote171 views1 answer
Trigger stock phpmyadmin
SQL
1 vote133 views1 answer
Tsql update datetime
SQL
0 vote152 views2 answers
Sql server select first day of previous year
SQL
0 vote145 views1 answer
To change the database owner in SQL server
SQL
1 vote200 views1 answer
Postgres set sequence value to max id
SQL
11 votes151 views3 answers
How to get last row of table in sql
SQL