SQLite修剪字符串中的结束字符

Question

使用SQLite.

ltrim(ltrim(substr(tablename.time, 11),'0123456789'),'-') as main_time

我有上面的trim函数,从我的字符串中删除前11个字符.

2013-10-28 09:29:57.987 -- Original String.
09:29:57.987            -- New String.

但是我仍然希望从字符串末尾删除最后四个字符,将其转换为以下字符:

09:29:57

Answer 1

用途LENGTH:

SUBSTR(your_string, 1,LENGTH(your_string)-4)

但是,在您的情况下,只需指定固定位置:

SUBSTR(tablename.time, 12, 8)