不确定如何从一个表中获取数据并将其移动到另一个表中

Question

我有一张桌子:

create table practice_table
(
    traffic_date    datetime ,
    door_one        integer ,
    door_two    integer 
)

有一些样本数据:

insert into practice_table(traffic_date, door_one, door_two) values ('12-Oct-2006' ,14500 ,11141)
insert into practice_table(traffic_date, door_one, door_two) values ('13-Oct-2006' ,6804 ,5263)
insert into practice_table(traffic_date, door_one, door_two) values ('14-Oct-2006' ,7550 ,6773)
insert into practice_table(traffic_date, door_one, door_two) values ('15-Oct-2006' ,6144 ,5211)
insert into practice_table(traffic_date, door_one, door_two) values ('16-Oct-2006' ,5680 ,3977)
insert into practice_table(traffic_date, door_one, door_two) values ('17-Oct-2006' ,5199 ,3918)
insert into practice_table(traffic_date, door_one, door_two) values ('18-Oct-2006' ,5298 ,3631)

我正在尝试将其移动到具有列的另一个表(称为destination_table)中:

month(datetime)traffic_count(整数)

如何在SQL中创建一个循环,在新表中为10月创建一行,其中包含door_one和door_two的总数,而不显式输入任何数据(例如月份)？

Answer 1

您可以使用光标,但如果我了解您尝试做什么,那么就没有必要了.

;WITH tmp AS (
    SELECT DATEADD(MONTH, DATEDIFF(MONTH, 0, traffic_date), 0) AS month_field, door_one, door_two
    FROM practice_table
)
INSERT INTO destination_table (month, traffic_count)
SELECT month_field, SUM(door_one + door_two)
FROM tmp
GROUP BY month_field