sql join

SELECT Coloumn_Name(s) FROM Table_1, Table_2 WHERE Table_1.Primary_key = Table_2.Foreign_key;

/*Two tables: CUSTOMERS table and ORDERS table.
ORDERS table contains STATUS attribute.*/
SELECT 
    customers.customerNumber, 
    customerName, 
    orderNumber, 
    status
FROM
    customers
LEFT JOIN orders ON 
    orders.customerNumber = customers.customerNumber;

SELECT Orders.OrderID, Customers.CustomerName, Orders.OrderDate
FROM Orders
INNER JOIN Customers ON Orders.CustomerID=Customers.CustomerID;

SELECT column_name(s)

FROM table1

LEFT JOIN table2
 ON table1.column_name = table2.column_name;
 

SELECT *
FROM Orders
LEFT JOIN Customers
=;

 SELECT Orders.OrderID, Customers.CustomerName, Orders.OrderDate
FROM Orders
INNER JOIN Customers ON Orders.CustomerID=Customers.CustomerID;
 

Suppose we are having three table named as 
Student_details
Attendance_details
Batch_details
And we have to apply join these three tables for fetching records

Example query:
select column_names
from Student_detail as s join Attendance_details as a on
s.s_id = a.s_id join Batch_details as b on 
s.s_id = b.s_id;

Here in the above example we implemented simple join but you change it with own join requirements.

SELECT column_name(s)

FROM table1

INNER JOIN table2
 ON table1.column_name = table2.column_name;