sql - PostgreSQL - 根据 3 列选择重复数据

Question

这是表格。

CREATE TABLE cameras
(
  id integer NOT NULL DEFAULT nextval('sq_streams'::regclass),
  created_at timestamp with time zone NOT NULL DEFAULT now(),
  updated_at timestamp with time zone NOT NULL DEFAULT now(),
  exid text NOT NULL,
  owner_id integer NOT NULL,
  is_public boolean NOT NULL,
  config json NOT NULL,
  name text NOT NULL,
  last_polled_at timestamp with time zone DEFAULT now(),
  is_online boolean,
  timezone text,
  last_online_at timestamp with time zone DEFAULT now(),
  location geography(Point,4326),
  mac_address macaddr,
  model_id integer,
  discoverable boolean NOT NULL DEFAULT false,
  preview bytea,
  thumbnail_url text,
  CONSTRAINT pk_streams PRIMARY KEY (id)
)

我有 5000 条记录。我想要得到的是以下结果: 有 57 个摄像头，它们各不相同，但有 3 个相同，它们是

'external_http_port', config->> 'external_host', config-> 'snapshots'->> 'jpg'

我想创建一个查询，将结果显示为

external_http_port | external_host | config-> 'snapshots'->> 'jpg' | Count
"93.87.73.118"     | "1024"        |      "/oneshotimage.jpg"      | 57
"180.180.180.48"   |  "81"         |"/onvif/media_service/snapshot"|20

Answer 1

这个呢？

SELECT config ->>'external_http_port' AS external_http_port, 
       config->> 'external_host' AS external_host, 
       config-> 'snapshots'->> 'jpg' AS snapshots,
       count(*) 
FROM cameras  
GROUP BY config->>'external_http_port', config->> 'external_host', config-> 'snapshots'->> 'jpg' 
HAVING count(*) > 1;