I have an SQL statement where I would like to get data of 1200 ep_codes
by making use of IN
clause. When I include more than 1000 ep_codes
inside IN clause, Oracle says I'm not allowed to do that. To overcome this, I tried to change the SQL code as follows:
SELECT period, ...
FROM my_view
WHERE period = '200912'
...
AND ep_codes IN (...1000 ep_codes...)
OR ep_codes IN (...200 ep_codes...)
The code was executed succesfully but the results are strange (calculation results are fetched for all periods, not just for 200912, which is not what I want). Is it appropriate to do that using OR
between IN
clauses or should I execute two separate codes as one with 1000 and the other with 200 ep_codes?
Pascal Martin's solution worked perfectly. Thanks all who contributed with valuable suggestions.
The recommended way to handle this in Oracle is to create a Temporary Table, write the values into this, and then join to this. Using dynamically created IN
clauses means the query optimizer does a 'hard parse' of every query.
create global temporary table LOOKUP
(
ID NUMBER
) on commit delete rows;
-- Do a batch insert from your application to populate this table
insert into lookup(id) values (?)
-- join to it
select foo from bar where code in (select id from lookup)
Not sure that using so many values in a IN()
is that good, actually -- especially for performances.
When you say "the results are strange", maybe this is because a problem with parenthesis ? What if you try this, instead of what you proposed :
SELECT ...
FROM ...
WHERE ...
AND (
ep_codes IN (...1000 ep_codes...)
OR ep_codes IN (...200 ep_codes...)
)
Does it make the results less strange ?
Actually you can use collections/multisets here. You'll need a number table type to store them.
CREATE TYPE NUMBER_TABLE AS TABLE OF NUMBER;
...
SELECT *
FROM my_view
WHERE period MEMBER OF NUMBER_TABLE(1,2,3...10000)
Read more about multisets here:
Seems like it would be a better idea, both for performance and maintainability, to put the codes in a separate table.
SELECT ...
FROM ...
WHERE ...
AND ep_code in (select code from ep_code_table)
could you insert the 1200 ep_code
values into a temporary table and then INNER JOIN
to that table to filter rows instead?
SELECT a.*
FROM mytable a
INNER JOIN tmp ON (tmp.ep_code = a.ep_code)
WHERE ...
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