Syntax
The syntax for SQL Inner Joins is as follows:
Select table1.<columnname1>, table1.<columnname2>, table2.<columnname1>, table2.<columnname2>from table1 INNER JOIN table2 ON table1.<column>=table2.<column>;
Table 1 and table 2 => The accurate table names inside the database.
Column name => The operation that can be performed on the column by using SQL Inner Joins.
Examples
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sql> create table customer(customer_id number(4),customer_name varchar2(20),city varchar2(20),country varchar2(20));
Query OK, 0 rows affected (0.49 sec)
sql> insert into customer values(1001,'James','Maria Anders','United states');
Query OK, 1 row affected (0.11 sec)
sql> insert into customer values(1002,'Mike','Trujillo','Germany');
Query OK, 1 row affected (0.09 sec)
sql> insert into customer values(1003,'Kate','Mataderos','France');
Query OK, 1 row affected (0.23 sec)
sql> select * from customer;
+-------------+---------------+--------------+---------------+
| customer_id | customer_name | city | country |
+-------------+---------------+--------------+---------------+
| 1001 | James | Maria Anders | United states |
| 1002 | Mike | Trujillo | Germany |
| 1003 | Kate | Mataderos | France |
+-------------+---------------+--------------+---------------+
3 rows in set (0.00 sec)
sql> create table orders(order_id number(4),customer_id number(4),employee_id number(4),shipper_id number(4));
Query OK, 0 rows affected (0.36 sec)
sql> insert into orders values(1101,1002,1011,3);
Query OK, 1 row affected (0.11 sec)
sql> insert into orders values(1102,12,1012,5);
Query OK, 1 row affected (0.17 sec)
sql> insert into orders values(1103,21,1033,7);
Query OK, 1 row affected (0.11 sec)
sql> select * from orders;
+----------+-------------+-------------+------------+
| order_id | customer_id | employee_id | shipper_id |
+----------+-------------+-------------+------------+
| 1101 | 1002 | 1011 | 3 |
| 1102 | 12 | 1012 | 5 |
| 1103 | 21 | 1033 | 7 |
+----------+-------------+-------------+------------+
3 rows in set (0.00 sec)
sql> Select customer.customer_name,orders.order_id from customer INNER JOIN orders on customer.customer_id=orders.customer_id order by customer.customer_name;
+---------------+----------+
| customer_name | order_id |
+---------------+----------+
| Mike | 1101 |
+---------------+----------+
1 row in set (0.14 sec)
sql> SELECT Orders.OrderID, Customers.CustomerName FROM Orders INNER JOIN Customers ON Orders.CustomerID = Customers.CustomerID;
+---------------+---------------+
| order_id | customer_name |
+---------------+---------------+
| 1101 | Mike |
+---------------+---------------+
1 row in set (0.14 sec)
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