官方参考文档:SQLite Query Language: Core Functions http://www.sqlite.org/lang_corefunc.html 测试SQL语句: ,) AS substr_0_20, substr(,) AS substr_0_19, substr(,) AS substr_1_19, substr() AS substr_19 WINDOW上的Navicat.Mac上的MesaSQLite.Android上SQLite上测试语句结果:substr_0…
oracle的substr函数的用法 取得字符串中指定起始位置和长度的字符串 substr( string, start_position, [ length ] ) 如: substr('This is a test', 6, 2) would return 'is' substr('This is a test', 6) would return 'is a test' substr('TechOnTheNet', -3, 3) would…
SQLite Database 自定义函数实现: //Here's how to create a function that finds the first character of a string. static void firstchar(sqlite3_context *context, int argc, sqlite3_value **argv) { ) { ]); ]) { ]; result[] = text[]; result[] = '\0'; sqlite3_resul…