Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
313 views
in Technique[技术] by (71.8m points)

sql - Doing a WHERE IN on multiple columns in Postgresql

I have a table 'answers' with an indexed 'problem_id' integer column, a 'times_chosen' integer column, and an 'option' column that's a varchar. Currently the only values for the 'option' column are 'A', 'B', 'C' and 'D', though those may expand later on. I want to increment by one the 'times_chosen' values of many (50-100) answers, when I know the problem_id and option of each of them.

So I need a query that's something like:

UPDATE answers
SET times_chosen = times_chosen + 1
WHERE (problem_id, option) IN ((4509, 'B'), (622, 'C'), (1066, 'D'), (4059, 'A'), (4740, 'A')...)

Is this possible?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You can join against a virtual table of sorts:

SELECT * FROM answers
JOIN (VALUES (4509, 'B'), (622, 'C'), (1066, 'D'), (4059, 'A'), (4740, 'A')) 
    AS t (p,o)
ON p = problem_id AND o = option

You can do something similar with UPDATE.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...