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From:Dan Nelson Date:August 29 2002 5:12am
Subject:Re: Join with Union
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In the last episode (Aug 29), suresh said:
> I dont really get your point Another thing I would like to highlight
> I thought UNION will be used to join to SQL Queries and will display
> only distinct values unless UNION ALL is used
> 
> I don't know why the result is wierd or I do some misunderstanding
> about UNION Here are the results of the query and UNION gives a
> result that is very ubnormal
> 
> Can anyone please explain why
> 
> mysql> SELECT a.order_id, a.order_name FROM orderdetails AS a WHERE a.order_id =
> '001';
> +----------+-------------+
> | order_id | order_name  |
> +----------+-------------+
> | 001      | palanichamy |
> +----------+-------------+
> 1 row in set (0.00 sec)
> 
> mysql> SELECT c.order_id, c.nature FROM complaints AS c WHERE c.order_id = '001'
> ;
> +----------+-----------------------+
> | order_id | nature                |
> +----------+-----------------------+
> | 001      | I cant read man       |
> | 001      | I cant install either |
> +----------+-----------------------+
> 2 rows in set (0.00 sec)
> 
> When union is used it gives the result
> mysql> SELECT a.order_id, a.order_name FROM orderdetails AS a WHERE a.order_id =
> '001'
> UNION ALL
> SELECT c.order_id, c.nature FROM complaints AS c WHERE c.order_id = '001' ;
> +----------+----------------------+
> | order_id | order_name           |
> +----------+----------------------+
> | 001      | palanichamy          |
> | 001      | I cant read man      |
> | 001      | I cant install eithe |
> +----------+----------------------+
> 3 rows in set (0.00 sec)

Apart from the missing 'r' in the last record, I don't see anything
unusual.  If that's what you're talking about, file a bug report with
mysqlbug.

-- 
	Dan Nelson
	dnelson@stripped
Thread
Join with Unionsuresh29 Aug
  • Re: Join with UnionDan Nelson29 Aug
  • Re: Join with UnionPaul DuBois29 Aug
Re: Join with UnionDan Nelson29 Aug