Android SQLite 加入自定义函数 _自定义

亦余心之所善兮，虽九死其犹未悔。这篇文章主要讲述Android SQLite 加入自定义函数相关的知识，希望能为你提供帮助。
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) { if (argc == 1) { char *text = sqlite3_value_text(argv[0]); if (text & & text[0]) { char result[2]; result[0] = text[0]; result[1] = ‘\0‘; sqlite3_result_text(context, result, -1, SQLITE_TRANSIENT); return; } } sqlite3_result_null(context); }//Then attach the function to the database.sqlite3_create_function(db, "firstchar", 1, SQLITE_UTF8, NULL, & firstchar, NULL, NULL); //Finally, use the function in a sql statement.//SELECT firstchar(textfield) from table

备注：aHR0cCUzQS8vd3d3LmNuYmxvZ3MuY29tL3poaGQv
参考代码：AOSP/external/sqlite/android/sqlite3_android.cpp
参考链接：http://stackoverflow.com/questions/7867099/how-can-i-create-a-user-defined-function-in-sqlite
【Android SQLite 加入自定义函数】参考链接：http://www.cnblogs.com/imouto/archive/2013/06/14/how-to-add-user-defined-functions-for-sqlite.html