How do I join 3 tables in SQL?

When you use SQL's JOIN function, it doesn't mean you can just join two tables: Using a Junction Table to Connect Three Tables The first step is to examine the schema and choose which columns to display. The next step is to figure out which tables are required for the query. We'll have to join all of the tables together at the end.

Course Content

Introduction to PHP

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Understanding SDLC Process

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How to use LearnVern

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Client Server Architecture

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How to set up PHP Environment?

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What is Data

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What is Database

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What is DBMS

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SQL Queries and its types

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Data Types in SQL - from 16

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SQL constraints

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Create, Drop & Show Database

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SQL Create Table

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SQL Insert & Select Statement

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Operators in SQL

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In & NOt in Condition

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Null & Not Null Condition

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Clauses in SQL

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Understanding Having, Distinct & Group by

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Update & Delete in SQL

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Alter table command in SQL

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MySQL Rename truncate Drop

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Understanding Foreign key

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MySQL joins

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MySQL views

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MySQL Function

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MySQL Procedure

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MySQL Trigger

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Variables in PHP

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Arithmetic & Assignment Operators in PHP

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Comparison & Logical Operators in PHP

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Ternary Operator in PHP

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Functions in PHP

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Call by value vs Call by reference in PHP

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Date and Time functions in PHP

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Include & Require Statement in PHP

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Error Handling in PHP

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Database Connection in PHP Part 1

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Database Connection in PHP Part 2

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SQL Injection in PHP

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Crud - Registration and DB connection Part 1

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Crud - Registration and DB connection Part 2

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Log in Operation

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Read Operation

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Update Operation Part 1

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Update Operation Part 2

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Log out Operation

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MySQL Interview Question 1

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MySQL Interview Question 2

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MySQL Interview Question 3

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MySQL joins

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Course Content

Introduction to PHP

10m 23s

Understanding SDLC Process

13m 58s

How to use LearnVern

3m 20s

Client Server Architecture

5m 18s

How to set up PHP Environment?

18m 6s

What is Data

8m 57s

What is Database

3m 25s

What is DBMS

14m 25s

SQL Queries and its types

16m 57s

Data Types in SQL - from 16

22m 41s

SQL constraints

10m 52s

Create, Drop & Show Database

13m 40s

SQL Create Table

13m 53s

SQL Insert & Select Statement

26m 56s

Operators in SQL

6m 47s

In & NOt in Condition

7m 4s

Null & Not Null Condition

4m 55s

Clauses in SQL

9m 46s

Understanding Having, Distinct & Group by

21m 54s

Update & Delete in SQL

12m

Alter table command in SQL

15m 29s

MySQL Rename truncate Drop

6m 34s

Understanding Foreign key

15m 37s

MySQL joins

22m 56s

MySQL views

18m 23s

MySQL Function

21m 39s

MySQL Procedure

15m 33s

MySQL Trigger

16m 15s

Normalization

16m 9s

Assignment : MYSQL

8m 56s

Understanding HTTP Methods

33m 26s

Understanding PHP Program structure Comments in PHP

13m 7s

Variables in PHP

11m 46s

Arithmetic & Assignment Operators in PHP

24m 28s

Comparison & Logical Operators in PHP

33m 17s

Ternary Operator in PHP

14m 38s

Assignment : Operators

1m 22s

Super Global Variable in PHP

19m 30s

GET & POST Variable in PHP

12m 21s

$_FILES & $_ENV in PHP

15m 24s

Assignment : Super Global Variables

2m 16s

If-else in PHP

26m 25s

switch case in PHP

15m 2s

Assignment : Conditional Statements

2m 28s

Functions in PHP

39m 46s

Call by value vs Call by reference in PHP

17m 28s

Assignment : Functions

5m 25s

Array Functions in PHP

44m 28s

Array in PHP

19m 35s

Assignment : Array

7m 18s

String and its Functions in PHP

27m 53s

Assignment : String

3m 44s

Loops in PHP

19m 28s

More examples on Loops in PHP

17m 20s

Assignment : Loops

8m 32s

Cookies in PHP

15m 45s

Session in PHP

35m 42s

Header Function in PHP

17m 11s

Assignment : Header Functions

1m 57s

Date and Time functions in PHP

36m 14s

Assignment : Date Time Functions

4m 29s

Include & Require Statement in PHP

13m 52s

Error Handling in PHP

15m 18s

File Upload in PHP

42m 55s

Database Connection in PHP Part 1

29m 17s

Database Connection in PHP Part 2

32m

SQL Injection in PHP

30m 33s

Crud - Registration and DB connection Part 1

31m 31s

Crud - Registration and DB connection Part 2

24m 2s

Log in Operation

27m 25s

Read Operation

30m 27s

Update Operation Part 1

12m 53s

Update Operation Part 2

27m 17s

Log out Operation

9m 29s

MySQL Interview Question 1

33m 7s

MySQL Interview Question 2

25m 23s

MySQL Interview Question 3

24m 27s

FAQs

A FOREIGN KEY ensures data integrity by ensuring that data is entered into the database in accordance with certain standards. When you extract/query data from a database, you utilise a JOIN to specify how the data should be selected.

When you use SQL's JOIN function, it doesn't mean you can just join two tables:

Using a Junction Table to Connect Three Tables
The first step is to examine the schema and choose which columns to display.
The next step is to figure out which tables are required for the query.
We'll have to join all of the tables together at the end.

INNER, LEFT OUTER, RIGHT OUTER, FULL OUTER, and CROSS are the five forms of JOIN defined by the ANSI standard SQL.

In MySQL, the default JOIN is an INNER JOIN, which retrieves all rows from both tables based on the specified keywords as long as the columns in both tables match.

An INNER JOIN in SQL is the same as a JOIN clause in that it joins rows from two or more tables. The consequence of an inner join of A and B is A intersect B, or the inner half of a Venn diagram intersection.