​The **join clause** is used to combine tables based on a common column and a join condition. An **equi join** is a type of join that combines tables based on matching values in specified columns.

Please remember that:

* The column names do not need to be the same.
* The resultant table contains repeated columns.
* It is possible to perform an equi join on more than two tables.

# Syntax

There are two ways to use equi join in SQL:

SELECT *
FROM TableName1, TableName2
WHERE TableName1.ColumnName = TableName2.ColumnName;
-- OR
SELECT *
FROM TableName1
JOIN TableName2
ON TableName1.ColumnName = TableName2.ColumnName;

In the *first* method, after the `SELECT` keyword, the names of the columns that are to be included in the result of the query are specified. The `*` operator is used if all the columns need to be selected. After the `FROM` keyword, the tables which need to be joined are specified. In the `WHERE` clause, the table and column names are specified along with an `=` operator.

In the *second* method, the `JOIN` keyword is used to join the tables based on the condition provided after the `ON` keyword.

# Example

The following tables have been created:

**1. product_list**
| **ID** | **Pname** |
| ---------- | ------------ | --------------- | ------- | ------------------------- |
| 1          | Apples         |
| 2          | Oranges        |
| 3         | Mangoes        |

**2. product_details**
| **ID** | **Brand** |**Origin**|
| ---------- | ------------ | --------------- | ------- | ------------------------- |
| 1          | Fresh Foods| USA        |
| 2          | Angro Ltd        |Pakistan

**3. brand_details**
| **Brand** |**OfficeAddress**|
| ---------- | ------------ | --------------- | ------- | ------------------------- |
| Fresh Foods| 123 Seattle USA        |
| Angro Ltd        |124 Lahore

/*Performing the equi join with two tables*/
SELECT * 
FROM product_list
JOIN product_details
ON product_list.ID = product_details.ID;
/*Performing the equi join with three tables*/
SELECT product_list.ID, product_list.Pname, 
product_details.Brand, product_details.Origin, 
brand_details.OfficeAddress
FROM product_list, product_details, brand_details
WHERE product_list.ID = product_details.ID 
and product_details.Brand = brand_details.Brand

What is an equi join in SQL?

Combines tables by matching values in specified columns, allowing for repeated columns and multi-table joins.

ID	Brand	Origin
1	Fresh Foods	USA
2	Angro Ltd	Pakistan