我找到了这个解operator does not exist: timestamp with time zone + integer in PostgreSql。

create function addit(timestamptz,int) returns timestamptz immutable language sql as $$
    select $1+ interval '1 hour'*$2
$$;
create operator + (leftarg =timestamptz, rightarg =int, procedure=addit);

create function minusit(timestamptz,int) returns timestamptz immutable language sql as $$
    select $1+ interval '-1 hour'*$2
$$;
create operator - (leftarg =timestamptz, rightarg =int, procedure=minusit);

创建+和-运算符，然后执行

set session myconstants.testb =  -1;
select start_time ,start_time - current_setting('myconstants.testb')::integer  from besoccer_team bt ;
select start_time ,start_time - current_setting('myconstants.testb')::integer  from besoccer_team bt ;

start_time是时间戳类型

set session myconstants.testb =  -1;
select  now()::timestamp  , now()::timestamp  - current_setting('myconstants.testb')::integer  from besoccer_team bt ;
select  now()::timestamp  , now()::timestamp  - current_setting('myconstants.testb')::integer  from besoccer_team bt ;

您需要将变量值强制转换为一个区间：

SELECT now()::time - current_setting('myconstants.testb')::interval

前缀表示法interval '....'仅适用于它后面的常量。

您也可以尝试make_interval。

SET session myconstants.test = 10;

SELECT
    now() + make_interval(mins => current_setting('myconstants.test')::int);