选择间隔，其中间隔数来自表（红移）答案

【问题标题】：SELECT interval where the number of interval is from table (redshift)选择间隔，其中间隔数来自表（红移）
【发布时间】：2016-12-10 16:25:36
【问题描述】：

在redshift中，我有查询

CREATE TABLE result_table AS(
  SELECT * FROM table_name
  WHERE issued_timestamp >= date_part(epoch, trunc(getdate())- interval '2 days' + interval '17 hours')*1000
        AND issued_timestamp < date_part(epoch, trunc(getdate())- interval '0 days' + interval '17 hours')*1000
);

我可以从另一个表中选择区间数吗？
例如我有一张桌子day_interval

day_since|day_until
21|5

所以我可以这样查询

CREATE TABLE result_table AS(
  SELECT * FROM table_name
  WHERE issued_timestamp >= date_part(epoch, trunc(getdate())- interval '2 days' + interval '17 hours')*1000
        AND issued_timestamp < date_part(epoch, trunc(getdate())- interval '5 days' + interval '17 hours')*1000
);

我试过了

CREATE TABLE result_table AS(
  SELECT * FROM table_name
  WHERE issued_timestamp >= date_part(epoch, trunc(getdate())- interval (SELECT day_since FROM "day_interval")' days' + interval '17 hours')*1000
        AND issued_timestamp < date_part(epoch, trunc(getdate())- interval '0 days' + interval '17 hours')*1000
);

但没用。

提前致谢

【问题讨论】：

标签： sql amazon-redshift

【解决方案1】：

间隔始终是文字。
interval 'x' days 或 interval x days 不起作用，但 -
x * interval '1' days 会。

CREATE TABLE result_table AS(
  SELECT * FROM table_name
  WHERE issued_timestamp >= date_part(epoch, trunc(getdate()) - (SELECT day_since FROM "day_interval") * interval '1 days' + interval '17 hours')*1000
        AND issued_timestamp < date_part(epoch, trunc(getdate())- interval '0 days' + interval '17 hours')*1000
);

【讨论】：

【解决方案2】：

如果我理解正确，您只需要JOIN：

CREATE TABLE result_table AS
  SELECT t.*
  FROM table_name t JOIN
       day_interval di
       ON t.issued_timestamp >= date_part(epoch, trunc(getdate()) - di.day_since * interval '2 days' + interval '17 hours') * 1000 AND
          t.issued_timestamp < date_part(epoch, trunc(getdate()) - di.day_until * interval '0 days' + interval '17 hours') * 1000
);

【讨论】：