When we need to use USING clause in the sql?For example in this below:SELECT emp_name, department_name, city FROM employees e JOIN departments d USING (department_id) JOIN locations l USING (location_id) WHERE salary > 10000; Can anyone explain what is mean of USING in this sql statement? or USING concept in brief? Thank you.

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Mar 21st, 2006
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kishore

Mar 23rd, 2006

HI,
Using clause is some thing like that we dont need to mention the join condition when we r retreiveing data from the multiple tables.when we use using clause that particular column name shud present in both the tables and the select query will automatically join those tables using the given column name in USING clause.

Guna Sagar Challa

Mar 27th, 2006

Hi,
The using clause in Oracle is to support ANSI standard SQL for writing joins.
The same query can be written in the form of
SELECT emp_name, department_name, city
FROM employees e, departments d, locations l
WHERE d.department_id = e.department_id
AND d.location_id = l.location_id
AND salary > 10000
Guna Sagar Challa

Rohan Deshpande

Jan 22nd, 2007

for e.g. if there are two common column names in the table then Mention the desire common column name in the USING clause....

ravikumarzee@gmail.com
Profile Answers by ravikumarzee@gmail.com Questions by ravikumarzee@gmail.com

Mar 9th, 2007

USING is also used while executing Dynamic SQL.

e.g.,

EXECUTE IMMEDIATE 'DELETE FROM dept WHERE deptno = :num'
USING dept_id;

hmounir
Profile Answers by hmounir

Nov 17th, 2009

In natural joins USING clause can be used to specify only those culomns that should be used for an equijion