The official reference documentation: SQLite Query Language: Core Functions http://www.sqlite.org/lang_corefunc.html
Test SQL statement:
SELECT substr('2012-12-12 10:11:12 fff',0,20) AS substr_0_20, substr('2012-12-12 10:11:12 fff',0,19) AS substr_0_19, substr('2012-12-12 10:11:12 fff',1,19) AS substr_1_19, substr('2012-12-12 10:11:12 fff',19) AS substr_19
Navicat on WINDOW, MesaSQLite on the Mac, SQLite statement on the test results on Android: substr_0_20 and substr_1_19 consistent results; substr_0_19 do not know why one would be less?
substr_0_20 | substr_0_19 | substr_1_19 | substr_19 |
2012-12-12 10:11:12 | 2012-12-12 10:11:1 | 2012-12-12 10:11:12 | 2 fff |
IOS on the FMDB test results: substr_0_20 do not know why would one more?
substr_0_20 | substr_0_19 | substr_1_19 | substr_19 |
2012-12-12 10:11:12 | 2012-12-12 10:11:12 | 2012-12-12 10:11:12 | 2 fff |
In the end what is it normal?
Reproduced in: https: //www.cnblogs.com/AsionTang/p/4397833.html