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* UPDATE query with variable number of OR conditions in WHERE
@ 2013-03-14 22:25 JORGE MALDONADO <jorgemal1960@gmail.com>
2013-03-14 23:58 ` Re: UPDATE query with variable number of OR conditions in WHERE Ben Morrow <ben@morrow.me.uk>
0 siblings, 1 reply; 3+ messages in thread
From: JORGE MALDONADO @ 2013-03-14 22:25 UTC (permalink / raw)
To: pgsql-sql
I am building an UPDATE query at run-time and one of the fields I want to
include in the WHERE condition may repeat several times, I do not know how
many.
UPDATE table1
SET field1 = "some value"
WHERE (field2 = value_1 OR field2 = value_2 OR .....OR field2 = value_n)
I build such a query using a programming language and, after that, I
execute it. Is this a good approach to build such a query?
Respectfully,
Jorge Maldonado
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: UPDATE query with variable number of OR conditions in WHERE
2013-03-14 22:25 UPDATE query with variable number of OR conditions in WHERE JORGE MALDONADO <jorgemal1960@gmail.com>
@ 2013-03-14 23:58 ` Ben Morrow <ben@morrow.me.uk>
2013-03-15 03:15 ` Re: UPDATE query with variable number of OR conditions in WHERE Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 1 reply; 3+ messages in thread
From: Ben Morrow @ 2013-03-14 23:58 UTC (permalink / raw)
To: jorgemal1960@gmail.com; pgsql-sql
Quoth jorgemal1960@gmail.com (JORGE MALDONADO):
>
> I am building an UPDATE query at run-time and one of the fields I want to
> include in the WHERE condition may repeat several times, I do not know how
> many.
>
> UPDATE table1
> SET field1 = "some value"
> WHERE (field2 = value_1 OR field2 = value_2 OR .....OR field2 = value_n)
>
> I build such a query using a programming language and, after that, I
> execute it. Is this a good approach to build such a query?
You can use IN for this:
UPDATE table1
SET field1 = "some value"
WHERE field2 IN (value_1, value_2, ...);
Ben
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^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: UPDATE query with variable number of OR conditions in WHERE
2013-03-14 22:25 UPDATE query with variable number of OR conditions in WHERE JORGE MALDONADO <jorgemal1960@gmail.com>
2013-03-14 23:58 ` Re: UPDATE query with variable number of OR conditions in WHERE Ben Morrow <ben@morrow.me.uk>
@ 2013-03-15 03:15 ` Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 0 replies; 3+ messages in thread
From: Tom Lane @ 2013-03-15 03:15 UTC (permalink / raw)
To: Ben Morrow <ben@morrow.me.uk>; +Cc: jorgemal1960@gmail.com; pgsql-sql
Ben Morrow <ben@morrow.me.uk> writes:
> Quoth jorgemal1960@gmail.com (JORGE MALDONADO):
>> I am building an UPDATE query at run-time and one of the fields I want to
>> include in the WHERE condition may repeat several times, I do not know how
>> many.
>>
>> UPDATE table1
>> SET field1 = "some value"
>> WHERE (field2 = value_1 OR field2 = value_2 OR .....OR field2 = value_n)
>>
>> I build such a query using a programming language and, after that, I
>> execute it. Is this a good approach to build such a query?
> You can use IN for this:
> UPDATE table1
> SET field1 = "some value"
> WHERE field2 IN (value_1, value_2, ...);
IN is definitely better style than a long chain of ORs. Another
possibility is to use = ANY(ARRAY):
UPDATE table1
SET field1 = "some value"
WHERE field2 = ANY (ARRAY[value_1, value_2, ...]);
This is not better than IN as-is (in particular, IN is SQL-standard and
this is not), but it opens the door to treating the array of values as a
single parameter:
UPDATE table1
SET field1 = "some value"
WHERE field2 = ANY ($1::int[]);
(or text[], etc). Now you can build the array client-side and not need
a new statement for each different number of comparison values. If
you're not into prepared statements, this may not excite you, but some
people find it to be a big deal.
regards, tom lane
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2013-03-14 22:25 UPDATE query with variable number of OR conditions in WHERE JORGE MALDONADO <jorgemal1960@gmail.com>
2013-03-14 23:58 ` Ben Morrow <ben@morrow.me.uk>
2013-03-15 03:15 ` Tom Lane <tgl@sss.pgh.pa.us>
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