查询中的 Heroku dataclip 变量替换

Question

我想在查询的顶部设置一些 parameters/variables 并在 Heroku Dataclips 的复杂查询中的几个地方使用它们。这是一个简单的例子：

WITH vars AS ( SELECT 
  '2018-01-07' AS calcdate,
  12345 AS salary
)
select * 
from taxes
where country_alpha3='USA' and year='2018' and active=true 
and subdivision_code='US-MEDI' 
and local_code is null
and start_date <= DATE(vars.calcdate) and end_date >= DATE(vars.calcdate) 
and lower_amount_cents <= vars.salary and upper_amount_cents >= vars.salary;

我在另一个答案（从 2013 年开始）中看到了这种代码风格，但它在今天的实际数据剪辑中不起作用。

Error: Your query couldn't be updated.

ERROR:  missing FROM-clause entry for table "vars" 
LINE 12: and start_date <=  DATE(vars.calcdate) and end_date >= DATE(v...
                                 ^

如果 vars.calcdate 和 vars.salary 改为常量，那么 SQL 可以正常工作。我认为这与 vars. 语法或用法有关。

Answer 1

我找到了解决方案。这是我认为的语法。 vars.name 的格式是不允许的（不确定我在哪里看到的）。

WITH vars AS ( SELECT
  DATE('2018-01-07') AS calcdate,
  12345 AS salary
)
select *
from taxes
where country_alpha3='USA' and year='2018' and active=true
and subdivision_code='US-MEDI'
and local_code is null
and start_date <= (SELECT calcdate from vars) and end_date >= (SELECT calcdate from vars)
and lower_amount_cents <= (SELECT salary from vars) and upper_amount_cents >= (SELECT salary from vars);

查询中的 Heroku dataclip 变量替换

Heroku dataclip variable substitution in query

postgresql

heroku

heroku-postgres