我如何在SQLite中传递用于触发器函数的变量？
/*
// this is the trigger definition
CREATE TEMPORARY TRIGGER 'insertTrigger' INSTEAD OF INSERT ON 'foo'
BEGIN
SELECT bar(NEW.id, NEW.timestamp); "
END;
//*/
void insert(sqlite3 *db, char *id, char *timestamp, void *context){
exec_query(db, "INSERT INTO foo(id,timestamp) VALUES(?,?)", id, timestamp);
}
void bar(sqlite3_context *context, int argc, sqlite3_value **argv){
char *id = (char*)sqlite3_value_text(argv[0]);
char *timestamp = (char*)sqlite3_value_text(argv[1]);
//how do I get context* ???
//this must be a thread safe function (i.e. multiple threads have their own sqlite3* and all execute queries (possibly including this one)
}
有没有一些解决方法来启用它？ 就像一个想法：
void insert(sqlite3 *db, char *id, char *timestamp, void *context){
sqlite3_mutex_enter(sqlite3_db_mutex(db));
sqlite3_user_setdata(db, context); //this doesnt exist
exec_query(db, "INSERT INTO foo(id,timestamp) VALUES(?,?)", id, timestamp);
sqlite3_mutex_leave(sqlite3_db_mutex(db));
}
void bar(sqlite3_context *context, int argc, sqlite3_value **argv){
char *id = (char*)sqlite3_value_text(argv[0]);
char *timestamp = (char*)sqlite3_value_text(argv[1]);
void *context_ = sqlite3_user_data(context);
}
还有其他一些方法可能可以完成此操作，例如sqlite3_get_auxdata函数，但我并不真正了解api的工作原理。
context不是你的查询的一部分，所以它不会在触发器函数中可用。
毕竟，您发送用于更新表的SQL语句可能（应该）根本不知道触发器！
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