mysql - sql 如果存在则插入，如果不存在则插入

Question

如果我的表“current_schedule”中已经有给定日期的数据，我需要获取该“id”并插入到另一个具有该“id”的表“统计”中。如果没有，我需要创建它，然后使用创建的“id”插入。我几乎完成了:

   cursor.execute("SELECT id FROM current_schedule WHERE date = '{}'".format(lessondate))
    idforme = cursor.fetchone()
    if cursor.fetchone():
        idforme = idforme[0]
        if flag == str_to_bool('true'):
            cursor.execute("INSERT INTO statistic (id_student, id_current_schedule,here) \
                    VALUES ('{}','{}',1)".format(id_student,idforme))
        if flag == str_to_bool('false'):
            cursor.execute("INSERT INTO statistic (id_student, id_current_schedule,here) \
                    VALUES ('{}','{}',0)".format(id_student,idforme))
    else:
        cursor.execute("INSERT INTO current_schedule (id_schedule, date) VALUES ('{}','{}')".format(id_schedule,lessondate))
        mysql.connection.commit()
        if flag == str_to_bool('true'):
            cursor.execute("INSERT INTO statistic (id_student, id_current_schedule,here) \
                    VALUES ('{}',LAST_INSERT_ID(),1)".format(id_student))
        if flag == str_to_bool('false'):
            cursor.execute("INSERT INTO statistic (id_student, id_current_schedule,here) \
                    VALUES ('{}',LAST_INSERT_ID(),0)".format(id_student))
    mysql.connection.commit()

但问题是它在“current_schedule”中创建了两次新数据，并且只有在那之后才开始将已创建的“id”(第一个)数据插入“statistic”中。

Answer 1

尝试一下怎么样，因为它基本上是相同的查询:

else:
    cursor.execute("INSERT INTO current_schedule (id_schedule, date) VALUES ('{}','{}')".format(id_schedule,lessondate))
    mysql.connection.commit()
    flagNum = 0 if flag == str_to_bool('false') else 1
    cursor.execute("INSERT INTO statistic (id_student, id_current_schedule,here) \
                VALUES ('{}',LAST_INSERT_ID(),{})".format(id_student, flagNum))
    mysql.connection.commit()