Question

我使用Rails 4.1，Ruby 2.1和groupdate gem 2.4

我有一个包含以下列的记录表：

：value（json）：day（datetime）

current_user.time_zone为用户提供了＆＃39;时区。

value给出一个像这样的json对象：

{"430"=>1079.27, "400"=>10.23 }

我试图为每周添加所有价值[＆＃39; 430＆＃39;]字段

这会产生错误

Record.where(:user_id => current_user.id).group_by_week(:day, time_zone: current_user.time_zone).sum("value#>>'{430}'")


   (40.3ms)  SELECT SUM(value#>>'{430}') AS sum_value_430, (DATE_TRUNC('week', (day::timestamptz - INTERVAL '6 day' - INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai') + INTERVAL '6 day' + INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai' AS week FROM "eats"  WHERE "eats"."user_id" = 53 AND (day IS NOT NULL) GROUP BY (DATE_TRUNC('week', (day::timestamptz - INTERVAL '6 day' - INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai') + INTERVAL '6 day' + INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai'
PG::UndefinedFunction: ERROR:  function sum(text) does not exist
LINE 1: SELECT SUM(value#>>'{430}') AS sum_total_nutr...
               ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
: SELECT SUM(value#>>'{430}') AS sum_value_430, (DATE_TRUNC('week', (day::timestamptz - INTERVAL '6 day' - INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai') + INTERVAL '6 day' + INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai' AS week FROM "eats"  WHERE "eats"."user_id" = 53 AND (day IS NOT NULL) GROUP BY (DATE_TRUNC('week', (day::timestamptz - INTERVAL '6 day' - INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai') + INTERVAL '6 day' + INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai'
ActiveRecord::StatementInvalid: PG::UndefinedFunction: ERROR:  function sum(text) does not exist
LINE 1: SELECT SUM(value#>>'{430}') AS sum_total_nutr...
               ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
: SELECT SUM(value#>>'{430}') AS sum_value_430, (DATE_TRUNC('week', (day::timestamptz - INTERVAL '6 day' - INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai') + INTERVAL '6 day' + INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai' AS week FROM "eats"  WHERE "eats"."user_id" = 53 AND (day IS NOT NULL) GROUP BY (DATE_TRUNC('week', (day::timestamptz - INTERVAL '6 day' - INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai') + INTERVAL '6 day' + INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai'

尝试后

Record.where(:user_id => current_user.id).group_by_week(:day, time_zone: current_user.time_zone).sum("CAST(value->>'430'AS integer)")

我得到了

ActiveRecord::StatementInvalid at /records
PG::InvalidTextRepresentation: ERROR:  invalid input syntax for integer: "1063.32"
: SELECT SUM(CAST(value->>'430'AS integer)) AS sum_cast_value_430_as_integer, (DATE_TRUNC('week', (day::timestamptz - INTERVAL '6 day' - INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai') + INTERVAL '6 day' + INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai' AS week FROM "records"  WHERE "records"."user_id" = 53 AND (day IS NOT NULL) GROUP BY (DATE_TRUNC('week', (day::timestamptz - INTERVAL '6 day' - INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai') + INTERVAL '6 day' + INTERVAL '0' hour) AT TIME ZONE 'Asia/Shanghai'

Answer 1

您可能需要将JSON类型字段强制转换为整数（为清楚起见，我已删除了其他查询方法）。

Record.sum("CAST(value->>'430'AS integer)")

Answer 2

你可以试试这个：

value = Record.where(:user_id => current_user.id).group_by_week(:day, time_zone: current_user.time_zone).pluck(:value)
sum = value.reduce(:+)

活动记录分组并与json数据相加

2 个答案: