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

sql - SQLite IF Exists Clause

How to write IF EXISTS as shown in below query in SQLite? I read somewhere that IF clause doesn't exist in SQLite. What would be a better alternative for this?

if exists (select username from tbl_stats_assigned where username = 'abc' )
    select 1 as uname
else
    select 0 as uname
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)

Just do it the standard SQL way:

select exists(
    select 1
    from tbl_stats_assigned
    where username = 'abc'
);

Assuming of course that your 1 and 0 are actually boolean values (which SQLite represents with one and zero just like MySQL).

That should work in any SQL database and some even have special optimizations to support that idiom.


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

...