//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 == ) {

        char *text = sqlite3_value_text(argv[]);

        if (text && text[]) {

          char result[];

          result[] = text[]; result[] = '\0';

          sqlite3_result_text(context, result, -, SQLITE_TRANSIENT);

          return;

        }

    }

    sqlite3_result_null(context);

}

//Then attach the function to the database.

sqlite3_create_function(db, "firstchar", , SQLITE_UTF8, NULL, &firstchar, NULL, NULL);

//Finally, use the function in a sql statement.

//SELECT firstchar(textfield) from table