Question

我正在尝试存储SQLAlchemy生成的SQL查询，以及每个运行所需的时间。我正在使用事件监听器来存储SQL：

statements = []

@listens_for(DBSession.get_bind(), "before_cursor_execute", named=True)
def before_cursor_execute(**kw):
    statements.append(kw['statement'])

我可以以某种方式使用相同的事件监听器来存储执行时间，还是应该使用其他东西？

Answer 1

您可以使用after_cursor_execute记录查询的开始时间，然后计算@event.listens_for(engine, "before_cursor_execute") def _record_query_start(conn, cursor, statement, parameters, context, executemany): conn.info["query_start"] = datetime.now() @event.listens_for(engine, "after_cursor_execute") def _calculate_query_run_time(conn, cursor, statement, parameters, context, executemany): print("this query took {}".format(datetime.now() - conn.info["query_start"]))中的差异，如下所示：

         String[] options = new String[]{
           "Existing Customer",
           "New Customer"
         };   

        int selection = 0;

        do{
            System.out.println("Please choose one of the following to determine whether you are a new or existing customer");
            for (int i = 0; i < options.length; i++) {
                System.out.printf("[%s] - %s%n",i+1, options[i]);
            }
            String input = new Scanner(System.in).nextLine();
            try{
                selection = Integer.parseInt(input);
            }catch(NumberFormatException e){
                System.out.println("That is not a vaild. Please select from one of the following options.");
                selection = 0;
            }
        }while(selection <= 0 || selection > options.length);

        switch(selection){
            case 1:
                System.out.println("Welcome Back");
                break;
            case 2:
                System.out.println("Hello, I see you are a new customer,");
                System.out.println("let's get your account setup!");
                break;
        }

如何记录SQLAlchemy生成的SQL和查询执行时间？

1 个答案: