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
258 views
in Technique[技术] by (71.8m points)

postgresql - How to get the count of current month Sunday's in psql?

How to get total number of Sunday's for given date in postgresql

Question&Answers: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 need EXTRACT:

SELECT 
    EXTRACT(DOW FROM DATE '2011-02-16') = 0; -- 0 is Sunday

This can result in true or false, it's a sunday or it's not. I have no idea what you mean by "total number" because that will always be 0 (the date is not a sunday) or 1 (the given data is a sunday).

Edit: Something like this?

SELECT 
    COUNT(*)
FROM
    generate_series(timestamp '2011-01-01', '2011-03-01', '1 day') AS g(mydate)
WHERE
    EXTRACT(DOW FROM mydate) = 0;

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

...