How to use join on in sql

JOIN ON in SQL combines records in multiple tables based on common fields. The usage is as follows: Define JOIN type: INNER JOIN, LEFT JOIN, RIGHT JOIN. Specify comparison operators: =, >, <, etc. Specify the connection field: used to match the column names of the two tables

JOIN ON in SQL

What is JOIN ON?

JOIN ON is a SQL statement used to combine records from two or more tables based on one or more fields in common between them.

Usage:

<code class="sql">SELECT *
FROM table1
JOIN table2 ON table1.key_field = table2.key_field;</code>

Parameters:

• table1 and table2 : The name of the table to be connected
• key_field: The name of the matching field (column) between the two tables

How to use JOIN ON?

1. Define JOIN types: The JOIN ON statement can create different JOIN types, such as INNER JOIN, LEFT JOIN and RIGHT JOIN.
2. Specify comparison operators: You can specify comparison operators (such as =, >, <) to match records in two tables.

3. Specify the join fields: Specify the join fields of the two tables in the ON clause to determine which records should be merged.

Example:

Consider the following two tables:

##ididnamedateaddressproduct_idphonequantity

Customers		Orders

To find all customers and its order, you can use the following JOIN ON statement:

<code class="sql">SELECT *
FROM Customers
JOIN Orders ON Customers.id = Orders.customer_id;</code>

Advantages:

Easily combine data from different tables
• Create More complex queries, linking multiple data sets
• Improving performance and reducing the use of subqueries and nested joins

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