Hi.
Without the real data, it looks like the table design could use some
normalization work: it seems there is too much data repeated in table d.
But yes, in the situation on hand, GROUP BY is a reasonable use.
Alternatively use DISTINCT, which will result in the same:
SELECT DISTINCT c.c1,c.c2,d.d2 FROM c LEFT JOIN d ON c2=d1
Btw, do you really need a LEFT JOIN (i.e. you have rows in c without
match in d)?
Bye,
Benjamin.
PS: It would be easier to follow your example if it was not abstracted
(column and table names).
On Mon, Dec 03, 2001 at 03:25:28PM -0000, [EMAIL PROTECTED] wrote:
[...]
> This is not a problem so much as checking that I am not missing
> something obvious, before I change the way my mind deals with this type
> of situation in MySQL.
>
> I have two tables
>
> Table c:
>
> +-----+-----+
> | c1 | c2 |
> +-----+-----+
> | 1 | foo |
> | 2 | bar |
> +-----+-----+
>
> Table d:
>
> +-----+-----------+-------+
> | d1 | d2 | d3 |
> +-----+-----------+-------+
> | foo | red card | shop1 |
> | bar | blue card | shop1 |
> | foo | red card | shop2 |
> | bar | blue card | shop2 |
> +-----+-----------+-------+
>
> Table d deliberately has multiple entries in d1
>
> I want to select data from both table c and d so that I return
>
> +-----+-----+-_---------+
> | c1 | c2 | d2 |
> +-----+-----+-----------+
> | 1 | foo | red card |
> | 2 | bar | blue card |
> +-----+-----+-----------+
>
> Basically I want the all of the data from table c but need to get some
> extra info e.g. descriptions from table d.
>
> Using:
>
> SELECT c.c1,c.c2,d.d2 FROM c LEFT JOIN d ON c2=d1
>
[...]
> I can GROUP BY c.c1 (unique row number) to return the results I want but
> I am not sure if this is the intended/best way to get this result.
>
[...]
--
[EMAIL PROTECTED]
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