Oracle FROM Clause

FROM clause is a mandatory clause in SELECT expression. It specifies the tables from which data is to be retrieved.

Syntax:

FROM table_name...  

Expressions...

Oracle FROM Clause Example: (with one table)

Let’s take an example to explain how to use FROM clause to retrieve data from one table. Consider a table “customers”.

Customer table:

CREATE TABLE  "CUSTOMERS"   

   (    "NAME" VARCHAR2(4000),   

    "AGE" NUMBER,   

    "SALARY" NUMBER,   

    "STATE" VARCHAR2(4000)  

   )  

/

Execute this query:

SELECT *  

FROM customers  

WHERE salary >= 20000  

ORDER BY salary ASC; 

Output:

Oracle FROM Clause Example: (with two tables)

Inner Join example:

Let’s take two tables “suppliers” and “order1”.

Suppliers:

Order1:

Execute the following query:

SELECT suppliers.supplier_id, suppliers.supplier_name, order1.order_number  

FROM suppliers  

INNER JOIN order1  

ON suppliers.supplier_id = order1.supplier_id;

Output: