我的列字段为字符串,例如ex。 start_age(“20”)和end_age(“40”)。
现在我想要年龄( 24为整数)介于start_age和age_age之间的用户。那么我怎样才能得到这个用户?
我尝试过这个查询
User.where("start_age < (?) AND end_age > (?)", age, age)
但收到此错误:
PG::UndefinedFunction: ERROR: operator does not exist: character varying < integer
提前致谢。
答案 0 :(得分:2)
写下:
User.where("start_age::integer <= :age AND end_age::integer >= :age", age: age)
# or equivalent
User.where(":age BETWEEN start_age::integer AND end_age::integer", age: age)
以下是一些演示:
test_dev=# select 20 between '1'::integer and '10'::integer as result;
result
--------
f
(1 row)
test_dev=# select 5 between '1'::integer and '10'::integer as result;
result
--------
t
(1 row)
test_dev=# select '12'::integer as number;
number
--------
12
(1 row)