In This Article, You Will Know About SQL JOINS.
SQL JOINS – Before moving ahead, let’s know a bit about SQL Aliases.
Table of Contents
SQL JOIN
The SQL JOIN clause is used to add two or more tables based on common values between them in rows & columns.
SYNTAX
SELECT TABLE.COLUMN(S)
FROM TABLE
INNER JOIN TABLE ON CONDITION(S)
Table name: Data_1
S.No | Name | Class |
1 | Alex | 5 |
2 | Rolex | 6 |
3 | Salex | 7 |
4 | Jalex | 8 |
5 | Kalex | 9 |
Table name: Data_2
S.No | Roll_No | Section_ID |
6 | 451 | A |
7 | 452 | B |
8 | 453 | C |
9 | 454 | D |
10 | 455 | E |
Example: Use the JOIN clause to add the tables based on common values in rows & columns.
SELECT Data_1.S.No, Data_1.Name, Data_2.Section_ID
FROM Data_1
INNER JOIN Data_2 ON Data_1.S.No = Data_2.S.No;
As a result, it returns a table after combining common data based on both tables.
S.No | Name | Section_ID |
1 | Alex | A |
2 | Rolex | B |
3 | Salex | C |
4 | Jalex | D |
5 | Kalex | E |
Different Types of SQL JOINs
Here are the different types of the JOINs in SQL:
INNER JOIN – It returns the common records from both tables.
LEFT JOIN – It returns all records from the left table and common records from the right table.
RIGHT JOIN – It returns all records from the right table and common records from the left table.
FULL JOIN – It returns all records common from either the left table or the right table.
If you find anything incorrect in the above-discussed topic and have further questions, please comment below.
