sql - Postgresql 选择常量

Question

在 Oracle 中，我可以选择一个常量值来填充列，如下所示:

Select 
     "constant" constantvalue,
     orders.name
from 
     orders

它会产生:

ConstantValue     Name
  constant       sandwich
  constant        burger

无论出于何种原因，当我尝试在 postgres 中执行此操作时，我收到此错误。

ERROR:  column "Constant" does not exist

这是我的代码

    select
        date_trunc('day', measurement_date + (interval '1 day' * (6 - extract(dow from measurement_date)))) week,
        "AROutstanding" colname,
        round(avg(Total_Outstanding),0) numbah
    from
                (
                select
                    measurement_date,

                    sum(cast(sum_of_dollars as numeric)) Total_Outstanding
                from
                    stock_metrics
                where
                    invoice_status not in  ('F','Write off')
                group by
                    measurement_date
                ) tt
            group by
                week

Answer 1

将双引号更改为单引号。

所以这样:

Select 
     "constant" as constantvalue,
     orders.name
from 
     orders

应该是这样的:

Select 
     'constant' as constantvalue,
     orders.name
from 
     orders