PostgreSQL中的强制转换

我有这个查询，当t.delete_req='1'和t.delete_req='0'时，我需要设置'yes'和'no'

SELECT t.id,t.activity_id,t.type,t.sub_type,t.name,t.description,t.source, 
CASE t.delete_req WHEN t.delete_req='1' THEN 'Yes' WHEN t.delete_req='0' THEN 'No' END from "activities" "t" 

它抛出和错误，并说一些铸造问题存在。下面是错误

ERROR:  operator does not exist: character = boolean
LINE 2: CASE t.delete_req WHEN t.delete_req='1' THEN 'Yes' WHEN t.de...
                          ^
HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.

现在我试着这样强制转换，//CAST（t.delete_req AS char）='1'

但我还是不能让它工作。错误是一样的

ERROR:  operator does not exist: character = boolean

在表中，t.delete_req是一个字符，定义如下

delete_req character(1) NOT NULL DEFAULT '0'::bpchar,

---

您必须稍微更改语法（格式清晰）：

或

---

tnx。我错过了那件事

delete_req character(1) NOT NULL DEFAULT '0'::bpchar,

select
    t.id,t.activity_id,t.type,t.sub_type,t.name,t.description,t.source, 
    case t.delete_req
        when '1' then 'Yes'
        when '0' then 'No'
    end
from activities as t

select
    t.id,t.activity_id,t.type,t.sub_type,t.name,t.description,t.source, 
    case
        when t.delete_req = '1' then 'Yes'
        when t.delete_req = '0' then 'No'
    end
from activities as t