问题陈述

我有表“event_statistics”，其定义如下：

CREATE TABLE public.event_statistics (\n    id int4 NOT NULL DEFAULT nextval(\'event_statistics_id_seq\'::regclass),\n    client_id int4 NULL,\n    session_id int4 NULL,\n    action_name text NULL,\n    value text NULL,\n    product_id int8 NULL,\n    product_options jsonb NOT NULL DEFAULT \'{}\'::jsonb,\n    url text NULL,\n    url_options jsonb NOT NULL DEFAULT \'{}\'::jsonb,\n    visit int4 NULL DEFAULT 0,\n    date_update timestamptz NULL,\nCONSTRAINT event_statistics_pkey PRIMARY KEY (id),\nCONSTRAINT event_statistics_client_id_session_id_sessions_client_id_id_for \nFOREIGN KEY \n(client_id,session_id) REFERENCES <?>() ON DELETE CASCADE ON UPDATE CASCADE\n)\nWITH (\n    OIDS=FALSE\n) ;\nCREATE INDEX regdate ON public.event_statistics (date_update \ntimestamptz_ops) ;\n

和表“客户”： …