Re: [SOLVED] UPDATE with WHERE clause on joined table

Am 29.07.2006 um 01:30 schrieb Erik Jones:

> Fabian Peters wrote:
>> Hi,
>>
>> I'm only very rarely using SQL, so please forgive me if I show any
>> obvious signs of ignorance...
>>
>> I've got three tables "customer", "address" and "country". I want
>> to set the "language" attribute on "customer" on rows returned by
>> a SELECT such as this:
>>
>> SELECT title, first_names, last_name, email, language,
>> country.country_name FROM ((customer JOIN address ON customer.eoid
>> = address.eoid_customer) JOIN country ON address.eoid_country =
>> country.eoid) WHERE email LIKE '%.es' AND country.country_name =
>> 'SPAIN';
>>
>> That is, I want to set the "language" to 'Spanish' where the
>> "customer.email" is like '%.es' and where "country.country_name"
>> is 'SPAIN'.
>>
>> I've tried all sorts of places to put the JOIN and the WHERE
>> clauses within the UPDATE statement, but I just don't get it.
>>
>> I'd be most grateful for any help...
>>
>> TIA
>>
>> Fabian
>>
>> P.S.: One of my sorry attempts looked like this - which updates
>> all rows in "customer" so I figure the WHERE clause is not where
>> it should be:
>>
>> UPDATE customer SET language = 'Spanish' FROM ((customer AS
>> customer_address JOIN address ON customer_address.eoid =
>> address.eoid_customer) JOIN country ON address.eoid_country =
>> country.eoid) WHERE customer.email LIKE '%.es' AND
>> country.country_name = 'SPAIN');
> The FROM clause is where you put relations other than the one you
> are updating. Try this:
>
> UPDATE customer
> SET language='Spanish'
> FROM address ad, country co
> WHERE customer.eoid=ad.eoid_customer AND ad.eoid_country=co.eoid
> AND co.country_name='SPAIN' AND customer.email LIKE '%.es';
>
> Note that for demonstration purposes I've aliased the join tables
> and that (unfortunately) you can't alias the update table.
>
> erik jones <erik(at)myemma(dot)com>
> software development
> emma(r)

Erik, thanks a lot! Works like a charm and is so much more concise
than my attempts.

cheers

Fabian