select id from shopline_customer where id not in (select id from shopline_customer_ext)
以上 SQL 跑不完.

SELECT c.id
FROM shopline_customer c
WHERE NOT EXISTS (
    SELECT 1
    FROM shopline_customer_ext e
    WHERE e.id = c.id
);

以上 SQL 只要 0.3 秒.

GPT 的解釋: (ps, id 是 primary key, 非 null)
🚨 一、為什麼會慢：NOT IN 的效能陷阱
NOT IN 會觸發「反半連接（anti-join）」掃描
PostgreSQL 必須逐筆比對左邊的每個 id
並檢查右邊的 id 是否不在其中
若右邊子查詢結果中出現任何 NULL，NOT IN 的邏輯會「不確定」，導致全表掃描與回退
即使 id 是主鍵（有索引），PostgreSQL 通常仍會展開為 Nested Loop Anti Join 或 Hash Anti Join，
當 shopline_customer 和 shopline_customer_ext 都是大表（例如數十萬筆），
時間就會暴漲。
⚠️ NOT IN + NULL 問題：
即使 id 欄位宣告為 NOT NULL，也可能因外層的隱含條件造成額外檢查負擔。
PostgreSQL 會多執行一次 Anti-Join NULL Filter，浪費時間。

這是使用新竹物流的範例程式  來源是UNT後台Web專案
* 新竹物流取得配號API必須先在專案加入WEB服務參考 (此專案命名是HctService)
* 取得配號是使用 HctService.Service1SoapClient -> TransData_Json() 來取得
  回傳資料因為有 面單(出貨標籤) 圖檔的Hex字串，所以回應訊息很大，建議一次僅處理兩筆出貨單
* 本範例程式有處理Hex字串轉圖檔程式

* 取得貨況的功能。是另一組專用API -> https://www.hct.com.tw/phone/searchGoods_Main_Xml.ashx
  * POST參數是xml再加密為base64字串
  * Response是base64字串，需解密為xml
  * 本程式範例有相關的使用與加解密功能 參考 GetDeliveryStatus

1. 使用 "具名的 ConnectionString"時，必需在 ODBC Data Sources (32-bit) 中設定，不是  ODBC Data Sources (64-bit)



2. 若日期或數字欄位為 Null 時，會無法轉換，此時必需用 "寫入查詢來指定要傳送的資料"

 

可參考本文章:

https://dba.stackexchange.com/questions/245990/postgresql-extremely-slow-count-with-index-simple-query

vacuum analyze insider_event;
執行了 7 分鐘

ALTER TABLE insider_event SET (autovacuum_vacuum_scale_factor = 0, autovacuum_analyze_scale_factor = 0,  autovacuum_vacuum_threshold = 10000, autovacuum_analyze_threshold = 10000);

跑了 1.2 分鐘

修改 work_mem:
https://www.pgmustard.com/blog/work-mem

記憶體調整
https://www.enterprisedb.com/postgres-tutorials/how-tune-postgresql-memory

Restful 的 API 範例，比較特別的是取得單一筆資料時，不是用一般常見的 {id} 而是用 get?id=xxx 的方式，以避免 XXS 的功擊。(不要把原網頁中的參數拼入 API 網址，要改用 Query String 的方式傳給 API)

using Ds;

using Ds.Gv;

using iText.Kernel.Geom;

using Microsoft.AspNetCore.Mvc;

using Microsoft.EntityFrameworkCore;

using NPOI.SS.Formula.Functions;

using NPOI.SS.Util;

using Su;

using System.Linq.Expressions;



namespace CallCampaign.Api

{

    /// <summary>

    /// 行銷活動

    /// </summary>

    [Route("api/call-campaign")]

    [ApiController]

    [SetAuthorizationFilter(Sh.AuthCode.不設限)]

    public class ReserveCampaignController : Controller

    {

        /// <summary>

        /// 取得行銷活動列表

        /// </summary>

        /// <param name="reserveCampaignName"></param>

        /// <param name="currentPage"></param>

        /// <param name="pageSize"></param>

        /// <param name="orderByName"></param>

        /// <param name="sort"></param>

        /// <returns></returns>

        /// <exception cref="Exception"></exception>

        [HttpGet("")]

        public async Task<object> ListAsync([FromQuery] string reserveCampaignName = "", [FromQuery] int? currentPage = 1, [FromQuery] int? pageSize = 20, [FromQuery] string orderByName = "OrderNo", [FromQuery] string sort = "asc")

        {

            if (pageSize > 500)

            {

                pageSize = 500;

            }



            if (!(sort == "asc" || sort == "desc"))

            {

                throw new CustomException(System.Net.HttpStatusCode.BadRequest, "sort只能是asc或desc");

            }



            var temp = new V_ReserveCampaign().GetType().GetProperty(orderByName);

            if (temp == null)

            {

                throw new CustomException(System.Net.HttpStatusCode.BadRequest, "不存在欄位");

            }



            Expression<Func<V_ReserveCampaign, bool>> q = p => p.Is_Deleted == "N"

                    && (string.IsNullOrEmpty(reserveCampaignName) || (p.ReserveCampaignName != null && p.ReserveCampaignName.Contains(reserveCampaignName)))

                    ;



            if (orderByName.ToLower().Trim() != "id")

            {

                orderByName += " " + sort + ", id desc";

            }

            else

            {

                orderByName += " " + sort;

            }



            var ct = NewContext.GvContext;

            var list = await ct.GetPageListAsync(q, columns: "Id, ReserveCampaignName, OrderNo, StartAt, EndAt, ModifierName, ModifyDate, CreatorName, CreateDate", page: currentPage ?? 1, pageSize: pageSize ?? 20, orderByName);

            //var list = await ct.GetPageListAsync(q, page: currentPage ?? 1, pageSize: pageSize ?? 20, orderByName + " " + sort);

            return list;

        }



        /// <summary>

        /// 取得行銷活動

        /// </summary>

        /// <param name="Id"></param>

        /// <returns></returns>

        /// <exception cref="Exception"></exception>

        [HttpGet("get")]

        public async Task<dynamic> GetAsync([FromQuery] int Id)

        {

            var res = await Ds.NewContext.GvContext.ReserveCampaigns.Where(r => r.Id == Id)

                .FirstOrDefaultAsync();



            if (res == null)

            {

                throw new CustomException(System.Net.HttpStatusCode.BadRequest, "查無資料 " + Id.ToString());

            }

            return res;

        }

                

        /// <summary>

        /// 建立行銷活動

        /// </summary>

        /// <param name="dto"></param>

        /// <returns></returns>

        /// <exception cref="CustomException"></exception>

        [HttpPost("")]

        public async Task<object> CreateAsync(Dtos.CreateReserveCampaign dto)

        {

            var ct = NewContext.GvContext;

            var res = await Models.ReserveCampaignHelper.CreateReserveCampaignAsync(ct, dto);

            return res;

        }



        /// <summary>

        /// 編輯行銷活動

        /// </summary>

        /// <param name="dto"></param>

        /// <returns></returns>

        /// <exception cref="CustomException"></exception>

        [HttpPatch("")]

        public async Task<object> UpdateAsync(Dtos.UpdateReserveCampaign dto)

        {

            var ct = NewContext.GvContext;

            var res = await Models.ReserveCampaignHelper.UpdateReserveCampaignAsync(ct, dto);

            return res;

        }



        /// <summary>

        /// 刪除行銷活動

        /// </summary>

        /// <param name="id"></param>

        /// <returns></returns>

        /// <exception cref="CustomException"></exception>

        [HttpDelete("")]

        public async Task<object> DeleteAsync([FromQuery] int id)

        {

            var res = await Ds.NewContext.GvContext.MarkDeleteAsync<Ds.Gv.ReserveCampaign>(id, Sh.ModifyInfo);

            return res;

        }

    }

}

再增加一個同步範例(只例出 action)

        /// <summary>

        /// 取得列表

        /// </summary>

        /// <param name="name"></param>

        /// <param name="currentPage"></param>

        /// <param name="pageSize"></param>

        /// <param name="orderByName"></param>

        /// <param name="sort"></param>

        /// <returns></returns>

        [HttpGet("")]

        public object List([FromQuery] string name = "", [FromQuery] int? currentPage = 1, [FromQuery] int? pageSize = 20, [FromQuery] string orderByName = "OrderNo", [FromQuery] string sort = "asc")

        {

            return "";

        }



        /// <summary>

        /// 取得明細資料

        /// </summary>

        /// <param name="Id"></param>

        /// <returns></returns>

        /// <exception cref="Exception"></exception>

        [HttpGet("get")]

        public object Get([FromQuery] int id)

        {

            return "";

        }



        /// <summary>

        /// 建立

        /// </summary>

        /// <param name="dto"></param>

        /// <returns></returns>

        /// <exception cref="CustomException"></exception>

        [HttpPost("")]

        public object Create(Dtos.PhysicalCheckUpType dto)

        {

            return "";

        }



        /// <summary>

        /// 編輯

        /// </summary>

        /// <param name="dto"></param>

        /// <returns></returns>

        /// <exception cref="CustomException"></exception>

        [HttpPatch("")]

        public object Update(Dtos.PhysicalCheckUpType dto)

        {

            return "";

        }



        /// <summary>

        /// 刪除

        /// </summary>

        /// <param name="id"></param>

        /// <returns></returns>

        /// <exception cref="CustomException"></exception>

        [HttpDelete("")]

        public object Delete([FromQuery] int id)

        {

            return 1;

        }

試了這兩個 Sample:

https://learn.microsoft.com/en-us/training/modules/store-local-data/4-exercise-store-data-locally-with-sqlite

和 

https://blazorhelpwebsite.com/ViewBlogPost/61

結果專案在 Windows 環境下都可以正常執行，但切換到 Android Emulator 就無法存檔。

在查了很多資料後，發現需要裝額外的 Package，需安裝的 Package 如下:

    <ItemGroup>

     <PackageReference Include="sqlite-net-pcl" Version="1.8.116" />

     <PackageReference Include="SQLiteNetExtensions.Async" Version="2.1.0" />

     <PackageReference Include="SQLitePCLRaw.bundle_green" Version="2.1.4" />

     <PackageReference Include="SQLitePCLRaw.core" Version="2.1.4" />

     <PackageReference Include="SQLitePCLRaw.lib.e_sqlite3" Version="2.1.4" />

     <PackageReference Include="SQLitePCLRaw.provider.dynamic_cdecl" Version="2.1.4" />

     <PackageReference Include="System.Data.DataSetExtensions" Version="4.5.0" />

    </ItemGroup>

其它的發現為:
1. 雙點專案，就可以開啟 csproj 檔案。下方的 ItemGroup 就是已安裝的 package

2. 可以把 chrome 連接到 Android Emulator 的方法，在網址列輸入以下指令:
chrome://inspect/#devices

問題：
在開出新分頁後，無法讀取 sessionStorage 的資料


可能原因：
Chrome 某個版本，Stop cloning sessionStorage for windows opened with noopener
a标签_blank默认 rel="noopener" ，所以a标签需要加入rel=“opener” 而才能像window.open("同源页面")这种方式新开的页面会复制之前的sessionStorage


解決方法：
開新分頁前，加入 rel=“opener”參數即可。
例：

<a href="http://..." target="_blank" rel="opener">Link</a>

$(".hlkPrint").click(function () {

    $("form").setPostDataToStorage();



    $("form").attr("rel", "opener");

    $("form").attr("target", "_blank");

    $("form").attr("action", "xxxxx.aspx");

    $("form").submit();

}); 

參考：
面试官：你确定多窗口之间sessionStorage不能共享状态吗？？？

在 Postgres 使用 TransactionScope 似乎很空易就會發生 Transaction Abort 的情況。所以必需自行實做 retry 的機制

            int tries = 0;

            while (tries < Su.PgSql.maxTransactionAborted)

            {

                try

                {

                    using (var scop = new System.Transactions.TransactionScope(TransactionScopeAsyncFlowOption.Enabled))

                    {

                        var context = ShopBandContext.Context;



                        updateCount = await context.UpdateAsync<MarketDiscount>(dto, Sc.ModifyInfo,

                            onlyColumns: "StartAt,EndAt,NewPrice,FrontEndMemo,BackEndMemo");



                        scop.Complete();

                        break; //這個 Break 很重要

                    }

                }

                catch (Exception ex)

                {

                    // 我發現因為是非同步模式，所以要檢查很多層的 InnerException

                    if (tries < Su.PgSql.maxTransactionAborted

                        && ((ex.InnerException != null && ex.InnerException is Npgsql.PostgresException && ((Npgsql.PostgresException)ex.InnerException).SqlState == "40001")

                            || (ex.InnerException.InnerException != null && ex.InnerException.InnerException is Npgsql.PostgresException && ((Npgsql.PostgresException)ex.InnerException.InnerException).SqlState == "40001")))

                    {

                        //隨機休息 10 ~ 20 ms, 等另一個 job 完工

                        System.Threading.Thread.Sleep(Su.MathUtil.Random.Next(10, 20));

                        tries++;

                    }

                    else

                    {

                        throw;

                    }

                }

            }

-- 自動更新某個欄位

CREATE OR REPLACE FUNCTION before_market_update ()
RETURNS TRIGGER AS 
$$
BEGIN
    NEW.LMDT = LocalTimeStamp;
    RETURN NEW;
END;
$$
LANGUAGE 'plpgsql';

CREATE TRIGGER updt_market
  BEFORE UPDATE
  ON "Market"
  FOR EACH ROW
  EXECUTE PROCEDURE before_market_update();

--建立 table (要記得改 XXX)
CREATE TABLE IF NOT EXISTS public.table_monitor
(
    table_name text COLLATE pg_catalog."default" NOT NULL,
    update_at timestamp without time zone NOT NULL DEFAULT now(),
    update_count bigint NOT NULL DEFAULT 0,
    CONSTRAINT table_monitor_pkey PRIMARY KEY (table_name)
)

TABLESPACE pg_default;

ALTER TABLE IF EXISTS public.table_monitor
    OWNER to XXX;

-- 這一段只要執行一次
CREATE OR REPLACE FUNCTION public.table_monitor_trigger_fnc()
    RETURNS trigger
    LANGUAGE 'plpgsql'
    COST 100
    VOLATILE NOT LEAKPROOF
AS $BODY$
BEGIN
     Update public.table_monitor Set update_count = update_count + 1, update_at = now()  Where table_name = TG_TABLE_NAME; 
RETURN NEW;
END;
$BODY$;

ALTER FUNCTION public.table_monitor_trigger_fnc()
    OWNER TO XXX;

-- 對於被監控的 table, 要執行以下的指令，記得 monitor_table_name 要改為 table 的名字(要符合大小寫)
INSERT INTO public.table_monitor (table_name, update_at, update_count) VALUES ('monitor_table_name', '2000-01-01', 0) ON CONFLICT DO NOTHING;

CREATE OR REPLACE TRIGGER table_monitor_trigger
    AFTER INSERT OR DELETE OR UPDATE 
    ON monitor_table_name
    FOR EACH STATEMENT
    EXECUTE FUNCTION public.table_monitor_trigger_fnc();

監控用的程式碼:

public static void UpdateTableCache()

{

    //標記自已是正在執行的 Thread. 讓舊的 Thread 在執行完畢之後, 應該會自動結束. 以防舊的 Thread 執行超過 10 秒.

    CurrentThreadId = System.Threading.Thread.CurrentThread.ManagedThreadId;



    try

    {

        //確認自已是正在執行的 Thread, 重覆執行. (另一個 Thread 插入執行)

        while (CurrentThreadId == System.Threading.Thread.CurrentThread.ManagedThreadId)

        {

            LastUpdateDate = DateTime.Now;



            foreach (var dbId in CachedDbs)

            {

                var sql = @"select * from table_monitor";



                var dt = Su.PgSql.DtFromSql(sql, dbId);



                foreach (DataRow row in dt.Rows)

                {

                    string changeId = row["update_count"].DBNullToDefault();

                    string CacheKey = TableCacheKey(dbId, row["table_name"].DBNullToDefault());

                    ObjectCache cache = MemoryCache.Default;



                    string OldValue = (string)cache[CacheKey];



                    if (OldValue == null)

                    {

                        cache.Set(CacheKey, changeId, DateTime.MaxValue);

                    }

                    else

                    {

                        if (changeId != OldValue)

                        {

                            cache.Remove(CacheKey);

                            cache.Set(CacheKey, changeId, DateTime.MaxValue);

                        }

                    }

                }

            }



            //每兩秒檢查一次

            System.Threading.Thread.Sleep(2000);

        }

    }

    catch (Exception)

    {

        //依經驗, 只要 DB 能通, 這裡幾乎不會有問題, 所以這裡暫時不處理, 未來有問題時可以考慮寫入文字檔比較好.

    }

}