timescaledb学习

create extension postgis; 
create extension postgis_topology;  
create extension fuzzystrmatch;  
create extension address_standardizer;  
create extension address_standardizer_data_us;  
create extension postgis_tiger_geocoder; 
CREATE TABLE sensor_data2 (
    time timestamptz,
    sensor_id integer,
    location geometry(Point),
    temperature double precision
);
INSERT INTO sensor_data2 (time, sensor_id, location, temperature)
VALUES ('2023-09-29 12:00:00', 1, ST_GeomFromText('POINT(123.333 31.555)', 4326), 25.5);

-- 创建超表，使用 "time" 作为时间列，使用 "mssi" 作为分布键，并指定分区数为 10
SELECT create_hypertable('public.shiphistory', 'time', 'mssi', 32767);

CREATE EXTENSION IF NOT EXISTS timescaledb CASCADE;
-- 创建一个新的超表
CREATE TABLE "public"."shiphistory" (
  "time" timestamptz(6) NOT NULL,
  "name" varchar(128) COLLATE "pg_catalog"."default" NOT NULL,
  "mssi" varchar(64) COLLATE "pg_catalog"."default" NOT NULL,
  "create_time" timestamptz(6) NOT NULL,
  "lat" float8 NOT NULL DEFAULT 0.0,
  "lon" float8 NOT NULL DEFAULT 0.0,
  "heading" float8,
  "speed" float8,    
    "location" geometry(Point)
);
-- 插入数据，如果子表不存在，它将自动创建
INSERT INTO public.shiphistory ("time", "name", "mssi", "create_time", "lat", "lon", "heading", "speed","location")
VALUES ('2023-09-29 12:00:00', 'Ship1', '1234', '2023-09-29 12:00:00', 38.123, -77.456, 90.0, 10.0);

INSERT INTO sensor_data2 (time, sensor_id, location, temperature)
VALUES ('2023-09-29 12:00:00', 1, ST_GeomFromText('POINT(123.333 31.555)', 4326), 25.5);

INSERT INTO public.shiphistory ("time", "name", "mssi", "create_time", "lat", "lon", "heading", "speed","location")
SELECT   now(),name,
  mssi,
  create_time,
  lat,
  lon,
  heading,
  speed, ST_GeomFromText('POINT(' || lon || ' ' || lat || ')', 4326) from shipdynamicpath
    
    
SELECT   now(),name,
  mssi,
  create_time,
  lat,
  lon,
  heading,
  speed, ST_GeomFromText('POINT(' || lon || ' ' || lat || ')', 4326) from shipdynamicpath limit 10;

-- 将新的超表转换为分布式超表
SELECT create_distributed_hypertable('public.new_shiphistory', 'new_distribution_key');
INSERT INTO "_timescaledb_internal"."_hyper_1_10_chunk" ("time", "name", "mssi", "create_time", "lat", "lon", "heading", "speed", "location") VALUES ('2023-09-29 14:49:34.980999+08', '航拖4002', '413374950', '2023-09-29 15:00:00.543994+08', '32.252695', '121.71682', '222', '9.60000038146973', ST_GeomFromText('POINT(121.61682 32.252695)'));

有个操蛋的问题，随机生成的表都是_hyper_2_50_chunk这种，然后我要根据mssi号来查询，拼接了下。创建
DROP TABLE IF EXISTS "_timescaledb_internal"."mssi_result";
CREATE TABLE "_timescaledb_internal"."mssi_result" (
  "table_name" text COLLATE "pg_catalog"."default",
  "mssi" varchar(64) COLLATE "pg_catalog"."default"
)
;

SELECT table_name, 
       (SELECT * FROM timescaledb_internal || '.' || table_name LIMIT 1) AS first_row
FROM "_timescaledb_internal".tables
WHERE table_schema = 'timescaledb_internal'
  AND table_type = 'BASE TABLE';
    
    SELECT table_name, 
       (SELECT * FROM "_timescaledb_internal" || '.' || table_name LIMIT 1) AS first_row
FROM information_schema.tables
WHERE table_schema = '_timescaledb_internal'
  AND table_type = 'BASE TABLE';

select * from "_timescaledb_internal"."_hyper_2_33_chunk"

DO $$ 
DECLARE
    table_name_text text;
    first_row_record record;
    first_row_jsonb jsonb;
    query text;
BEGIN
    -- 如果临时表已经存在，先删除它
    --IF EXISTS (SELECT 1 FROM information_schema.tables WHERE table_name = 'temp_result') THEN
    --    DROP TABLE temp_result;
    --END IF;

    -- 创建临时表用于存储结果
    --CREATE TEMP TABLE temp_result (table_name text, first_row jsonb);
        
        truncate table mssi_result;
    
    FOR table_name_text IN
        SELECT table_name
        FROM information_schema.tables
        WHERE table_schema = '_timescaledb_internal'
          AND table_type = 'BASE TABLE' AND table_name LIKE '%_hyper%'
                    
    LOOP
        -- 构建查询
        --query := 'SELECT * FROM ' || table_name_text || ' LIMIT 1';
                query := 'SELECT mssi FROM ' || table_name_text || ' LIMIT 1';
        
        -- 执行查询并将结果存储在 first_row_record 中
        EXECUTE query INTO first_row_record;
        
        -- 将 record 转换为 jsonb
        --first_row_jsonb := to_jsonb(first_row_record);
        
        -- 将 table_name_text 和 first_row_jsonb 插入到 temp_result 表中
       --INSERT INTO temp_result (table_name, first_row) VALUES (table_name_text, first_row_jsonb);
                INSERT INTO mssi_result (table_name, mssi) VALUES (table_name_text, first_row_record.mssi);
    END LOOP;
        
    -- 输出 temp_result 表中的所有记录
    --FOR first_row_record IN SELECT * FROM temp_result
    --LOOP
        -- 现在您可以在 first_row_record 变量中处理结果
        -- 例如，您可以使用 first_row_record.table_name 和 first_row_record.first_row 访问具体字段
        
        --RAISE NOTICE 'Table: %, First Row: %', first_row_record.table_name, first_row_record.first_row;
    --END LOOP;
END $$;

整理下，在public 下创建函数
CREATE OR REPLACE FUNCTION process_hyper_tables_and_mssi()
RETURNS void AS $$
DECLARE
    table_name_text text;
    first_row_record record;
    query text;
BEGIN
    -- 清空表 _timescaledb_internal.mssi_result
    TRUNCATE TABLE _timescaledb_internal.mssi_result;

    FOR table_name_text IN
        SELECT table_name
        FROM information_schema.tables
        WHERE table_schema = '_timescaledb_internal'
          AND table_type = 'BASE TABLE' AND table_name LIKE '%_hyper%'
    LOOP
        -- 构建查询
        query := 'SELECT mssi FROM _timescaledb_internal.' || table_name_text || ' LIMIT 1';
        
        -- 执行查询并将结果存储在 first_row_record 中
        EXECUTE query INTO first_row_record;
        
        -- 将结果插入表 _timescaledb_internal.mssi_result
        INSERT INTO _timescaledb_internal.mssi_result (table_name, mssi) VALUES (table_name_text, first_row_record.mssi);
    END LOOP;
END;
$$ LANGUAGE plpgsql;