Oracle SELECT Statement

The Oracle SELECT statement is used to retrieve data from one or more than one tables, object tables, views, object views etc.

Syntax

  SELECT expressions  

FROM tables  

WHERE conditions;  

Parameters

1) expressions: It specifies the columns or calculations that you want to retrieve.

2) tables:This parameter specifies the tables that you want to retrieve records from. There must be at least one table within the FROM clause.

3) conditions: It specifies the conditions that must be followed for selection.

Select Example: select all fields

Let’s take an example to select all fields from an already created table named customers

SELECT *  

FROM customers;

output

Select Example: select specific fields

Example

SELECT age, address, salary  

FROM customers  

WHERE  age < 25  

AND salary > '20000'  

ORDER BY age ASC, salary DESC; 

Select Example: select fields from multiple tables (JOIN)

SELECT customers.name, courses.trainer  

FROM courses  

INNER JOIN customers  

ON courses.course_id = course_id  

ORDER BY name;

output