Difference between revisions of "Union"

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Make union between different tables to build one single view or request?
 
Make union between different tables to build one single view or request?
 
<div class='ht'>
 
<div class='ht'>
 +
<div class=params>schema:scott</div>
 
<div>
 
<div>
 
List a number of SELECT statements separated by the UNION key word. Be sure that you have the same number of columns in each of the SELECT statements.  
 
List a number of SELECT statements separated by the UNION key word. Be sure that you have the same number of columns in each of the SELECT statements.  
 
</div>
 
</div>
<source lang=sql class='tidy'>CREATE TABLE bbc (name VARCHAR(10), region VARCHAR(10));
+
<source lang=sql class='tidy'>DROP TABLE bbc;</source>
 +
<source lang=sql class='setup'>CREATE TABLE bbc (name VARCHAR(10), region VARCHAR(10));
 
INSERT INTO bbc VALUES ('Poland', 'Europe');
 
INSERT INTO bbc VALUES ('Poland', 'Europe');
 
INSERT INTO bbc VALUES ('Japan', 'Asia');
 
INSERT INTO bbc VALUES ('Japan', 'Asia');
 
</source>
 
</source>
 +
 
<source lang='sql' class='def e-access'>
 
<source lang='sql' class='def e-access'>
 
SELECT name FROM actor WHERE name LIKE 'Z%'
 
SELECT name FROM actor WHERE name LIKE 'Z%'

Revision as of 10:58, 12 July 2012

Make union between different tables to build one single view or request?

schema:scott

List a number of SELECT statements separated by the UNION key word. Be sure that you have the same number of columns in each of the SELECT statements.

DROP TABLE bbc;
CREATE TABLE bbc (name VARCHAR(10), region VARCHAR(10));
INSERT INTO bbc VALUES ('Poland', 'Europe');
INSERT INTO bbc VALUES ('Japan', 'Asia');
SELECT name FROM actor WHERE name LIKE 'Z%'
UNION
SELECT name FROM bbc WHERE name LIKE 'Z%'
SELECT name FROM actor WHERE name LIKE 'Z%'
UNION
SELECT name FROM bbc WHERE name LIKE 'Z%'
SELECT name FROM actor WHERE name LIKE 'Z%'
UNION
SELECT name FROM bbc WHERE name LIKE 'Z%'
SELECT name FROM actor WHERE name LIKE 'Z%'
UNION
SELECT name FROM bbc WHERE name LIKE 'Z%'
UNION will be available from version 4
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