CS50：LIKE运算符，具有％扩展的变量替换

将整个搜索字符串作为参数传递给LIKE 运算符 ：

results = db.execute(text("SELECt * FROM books WHERe title LIKE :search"),          {"search": f"%{search}%"}).fetchall();

或串联在数据库中：

results = db.execute(    text("SELECt * FROM books WHERe title LIKE ('%' || :search || '%')"),    {"search": search}).fetchall();