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Newtonsoft.Json.JsonConvert.DeserializeObject 失敗的情況
test...more
dotnet ef dbcontext scaffold
...more
[ASP.NET] 利用 aspnet_regiis 加密 web.config
...more
IIS ARR (reverse proxy) 服務安裝
...more
[錯誤訊息] 請加入 ScriptResourceMapping 命名的 jquery (區分大小寫)
...more
用 Javascript 跨網頁讀取 cookie (Cookie cross page, path of cookie)
...more
線上客服 - MSN
本人信箱被盜用以致資料外洩，是否可以請貴平台予以協助刪除該信箱之使用謝謝囉...more
插入文字到游標或選取處
aaaaa...more
IIS 配合 AD (Active Directory) 認証, 使用 .Net 6.0
太感謝你了~~~你救了我被windows 認證卡了好幾天QQ...more
PostgreSQL 的 monitor trigger
FOR EACH ROW 可能要改為 FOR EACH STATEMENT ...more

標籤

搜尋 table 結果：

流量異常原因查找

由實體機追查哪一台 VM 的流量最大

# 抓取第一次數據
$before = Get-Counter -Counter @(
'\Hyper-V Virtual Network Adapter(*)\Bytes Sent/sec',
'\Hyper-V Virtual Network Adapter(*)\Bytes Received/sec'
)

# 等待 10 秒
Start-Sleep -Seconds 10

# 抓取第二次數據
$after = Get-Counter -Counter @(
'\Hyper-V Virtual Network Adapter(*)\Bytes Sent/sec',
'\Hyper-V Virtual Network Adapter(*)\Bytes Received/sec'
)

# 分析並計算平均每秒流量
$results = @()

for ($i = 0; $i -lt $before.CounterSamples.Count; $i++) {
$instance = $before.CounterSamples[$i].InstanceName

$sentIndex = $i
$recvIndex = $i + $before.CounterSamples.Count / 2

$sentBefore = $before.CounterSamples[$sentIndex].CookedValue
$sentAfter = $after.CounterSamples[$sentIndex].CookedValue

$recvBefore = $before.CounterSamples[$recvIndex].CookedValue
$recvAfter = $after.CounterSamples[$recvIndex].CookedValue

$sentPerSec = ($sentAfter - $sentBefore) / 10
$recvPerSec = ($recvAfter - $recvBefore) / 10

$results += [PSCustomObject]@{
AdapterName = $instance
SentPerSec = [math]::Round($sentPerSec, 2)
ReceivedPerSec = [math]::Round($recvPerSec, 2)
TotalPerSec = [math]::Round($sentPerSec + $recvPerSec, 2)
}
}

# 顯示結果，依照總流量排序
$results | Sort-Object TotalPerSec -Descending | Format-Table -AutoSize

用 performance monitor 監查看各VM的流量(找不到)
Get-Counter '\Hyper-V Virtual Network Adapter(*)\Bytes Total/sec'

在 VM 上追查哪個網站流量最大
用 performance monitor 監查看各網站的流量
Web Service: Bytes Sent/sec

More...

Bike, 2025/8/4 上午 11:11:06

Chrome 連接藍芽 BLE 印表機(出單機)，使用 ESC / POS 列印繁體中文和 Qrcode

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <meta name="viewport" content="width=device-width, initial-scale=1.0">

    <title>BLE Printer Test</title>

    <script src="https://cdn.jsdelivr.net/npm/iconv-lite-umd@0.6.10/lib/iconv-lite-umd.js"></script>

</head>

<body>

    <h1>BLE Printer Test 123</h1>

    <button id="printTestButton">Test Print</button>

    <button id="printAgain">Print Again</button>

    <pre id="log"></pre>

    <script>

        // Function to log messages on the page

        function logMessage(message) {

            const logElement = document.getElementById('log');

            logElement.textContent += message + '\n';

        }

        var device;

        var server;

        var service;

        var characteristic;

        var name = 'T58_6752'; // 藍芽設備的名稱

        var uuid = 0x1800; //service UUID (用 BLE Scanner 找到的)

        var characteristicUuid = 0x2A00; // characteristic UUID (用 BLE Scanner 找到的)

        // Function to connect to BLE printer and send test data



        async function connectAndTestPrint() {



            try {

                logMessage("Requesting Bluetooth device...");



                // Request the BLE device

                device = await navigator.bluetooth.requestDevice({

                    //acceptAllDevices: true,

                    filters: [

                        { name: name }

                    ],

                    optionalServices: [uuid] // Replace with the correct service UUID

                });



                logMessage(`Device selected: ${device.name}`);

                logMessage(`Device uuid: ${device.id}`);



                await printAgain();





            } catch (error) {

                logMessage(`Error: ${error.message}`);

            }

        }



        // 转码方法

        function stringToGbk(str) {

            const ranges = [

                [0xA1, 0xA9, 0xA1, 0xFE],

                [0xB0, 0xF7, 0xA1, 0xFE],

                [0x81, 0xA0, 0x40, 0xFE],

                [0xAA, 0xFE, 0x40, 0xA0],

                [0xA8, 0xA9, 0x40, 0xA0],

                [0xAA, 0xAF, 0xA1, 0xFE],

                [0xF8, 0xFE, 0xA1, 0xFE],

                [0xA1, 0xA7, 0x40, 0xA0],

            ]

            const codes = new Uint16Array(23940)

            let i = 0



            for (const [b1Begin, b1End, b2Begin, b2End] of ranges) {

                for (let b2 = b2Begin; b2 <= b2End; b2++) {

                    if (b2 !== 0x7F) {

                        for (let b1 = b1Begin; b1 <= b1End; b1++) {

                            codes[i++] = b2 << 8 | b1

                        }

                    }

                }

            }

            const cstr = new TextDecoder('gbk').decode(codes)



            // 编码表

            const table = new Uint16Array(65536)

            for (let i = 0; i < cstr.length; i++) {

                table[cstr.charCodeAt(i)] = codes[i]

            }

            const buf = new Uint8Array(str.length * 2)

            let n = 0



            for (let i = 0; i < str.length; i++) {

                const code = str.charCodeAt(i)

                if (code < 0x80) {

                    buf[n++] = code

                } else {

                    const gbk = table[code]

                    buf[n++] = gbk & 0xFF

                    buf[n++] = gbk >> 8

                }

            }

            u8buf = buf.subarray(0, n)

            // console.log(u8buf);

            return u8buf

        }



        async function printAgain() {

            // Connect to the GATT server

            server = await device.gatt.connect();

            logMessage("Connected to GATT server.");



            // Get the printer service

            service = await server.getPrimaryService(uuid); // Replace with your printer's service UUID

            logMessage("Printer service retrieved.");



            // Get the characteristic for writing data

            characteristic = await service.getCharacteristic(characteristicUuid); // Replace with the correct characteristic UUID

            logMessage("Printer characteristic retrieved.");



            // Prepare test print data

            const encoder = new TextEncoder();

            const testData = encoder.encode("TEST PRINT: Hello from Web Bluetooth!\n");

            const finalData = encoder.encode("--\n--\n \n \n");



            const setFontSize = new Uint8Array([0x1D, 0x21, 0x11]); // GS ! n

            const setFontSize2 = new Uint8Array([0x1D, 0x21, 0x22]); // GS ! n

            const setFontSize3 = new Uint8Array([0x1D, 0x21, 0x33]); // GS ! n



            // Write test data to the printer

            logMessage("Sending test data to printer...");



            await characteristic.writeValue(new Uint8Array([0x1D, 0x21, 0x00]));

            await characteristic.writeValue(encoder.encode("1x1!\n"));

            await characteristic.writeValue(setFontSize);

            await characteristic.writeValue(encoder.encode("2x2!\n"));

            await characteristic.writeValue(setFontSize2);

            await characteristic.writeValue(encoder.encode("3x3!\n"));

            await characteristic.writeValue(setFontSize3);

            await characteristic.writeValue(encoder.encode("4x4!\n"));





            const initPrinter = new Uint8Array([0x1B, 0x40]); // ESC @

            await characteristic.writeValue(initPrinter);



            // 3. 設置字符集為 GBK

            const setGBK = new Uint8Array([0x1B, 0x74, 0x11]); // ESC t 0x11 (GBK)

            await characteristic.writeValue(setGBK);



            const text = "繁體中文測試\n \n";

            const encodedText = stringToGbk(text);

            await characteristic.writeValue(encodedText);

            logMessage("Test data sent successfully!");



            // QrCode 列印

            const qrData = "https://example.com"; // Your QR code data

            const qrDataLength = qrData.length + 3;

            const pL = qrDataLength & 0xFF; // Low byte

            const pH = (qrDataLength >> 8) & 0xFF; // High byte



            const commands = [

                0x1B, 0x40, // Initialize printer

                0x1D, 0x28, 0x6B, pL, pH, 0x31, 0x50, 0x30, ...new TextEncoder().encode(qrData), // Store data

                0x1D, 0x28, 0x6B, 0x03, 0x00, 0x31, 0x51, 0x30 // Print QR code

            ];



            const buffer = new Uint8Array(commands);

            await characteristic.writeValue(buffer);

            logMessage("QrCode sent successfully!");



            await characteristic.writeValue(finalData);

            logMessage("finalData sent successfully!");



            // Disconnect the GATT server

            server.disconnect();

            logMessage("Disconnected from printer.");

        }



        // Bind the function to the button

        document.getElementById('printTestButton').addEventListener('click', connectAndTestPrint);

        document.getElementById('printAgain').addEventListener('click', printAgain);

    </script>

</body>

</html>

More...

Bike, 2025/1/2 下午 02:20:15

postgreSql 大型 table 跑 Count 非常慢

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

More...

Bike, 2024/2/5 上午 06:55:40

查詢佔用 CPU 的排程

DECLARE @tblVariable TABLE(SPID INT, Status VARCHAR(200), [Login] VARCHAR(200), HostName VARCHAR(200),
BlkBy VARCHAR(200), DBName VARCHAR(200), Command VARCHAR(200), CPUTime INT,
DiskIO INT, LastBatch VARCHAR(200), ProgramName VARCHAR(200), _SPID INT,
RequestID INT)

INSERT INTO @tblVariable
EXEC Master.dbo.sp_who2

SELECT v.*, t.TEXT
FROM @tblVariable v
INNER JOIN sys.sysprocesses sp ON sp.spid = v.SPID
CROSS APPLY sys.dm_exec_sql_text(sp.sql_handle) AS t
ORDER BY BlkBy DESC, CPUTime DESC

kill xxx

參考: https://learn.microsoft.com/en-us/answers/questions/842347/sql-server-how-to-find-out-who-lock-my-specific-ta

More...

Bike, 2023/8/17 上午 10:44:05

Entity Framework 用起來和 Daper 越來越像了

Entity Framework 提供了 ExecuteSqlRawAsync 和 FromSqlRaw 之後，可以和 Dapper 非常類似的用法。

我們在用 Dapper 時。最常用的就是 sql command 加上一個物件做為參數，就可以執行 CRUD 的動作。

其實用 Entity Framework 的 ExecuteSqlRawAsync 和 FromSqlRaw 也可以逹到幾乎一樣的效果。

ExecuteSqlRawAsync 和 FromSqlRaw 接受的參數是 object array (其實是 Microsoft.Data.SqlClient.SqlParameter 的 array)

所以我們先做一個 Object to Microsoft.Data.SqlClient.SqlParameter Array 的擴充, 可參考: https://gist.github.com/aliozgur/75182b2e9b0a58b83443

不過很奇怪的是，原作者提供的擴充轉出來的會是 System.Data.SqlClient.SqlParameter Array 無法直接使用於 ExecuteSqlRawAsync 和 FromSqlRaw，所以要稍微改一下，把 using System.Data.SqlClient; 改為 using Microsoft.Data.SqlClient; 即可:

另外，我們再自行對 DbContext 做一個擴充如下:

        /// <summary>

        /// 會把物件 Parameter 的各 Property 帶入 SQL 中.

        /// </summary>

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

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

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

        /// <returns></returns>

        public static async Task<int> ExecuteParameterSqlAsync(this DbContext dbct, string sql, object parameters)

        {

            return await dbct.Database.ExecuteSqlRawAsync(sql, parameters.ToSqlParamsArray());

        }

最後的結果可以做到以下的效果: (res3 和 res4 是配合 FormattableString 的範例 )

範例程式碼:

        public async Task<object> EfTest()

        {

            var dbct = Ds.NewContext.GvContext;

            var insertSql = @"Insert into ProfileEvent(JobId,[Name],GvShoplineId,LiShoplineId,Phone,Email,LineId,GaClientId)

            Values(@JobId, @Name, null , null , null , @Email, @GaClientId , @GaClientId )";



            //執行 SQL 的原生寫法

            await dbct.Database.ExecuteSqlRawAsync(insertSql, new object[]

            {

                new SqlParameter("@JobId", 10),

                new SqlParameter("@Email", "XX'TT"),

                new SqlParameter("@Name", "AA'BB"),

                new SqlParameter("@GaClientId", "GaClientId"),

            });



            //執行 SQL 的擴充寫法

            await dbct.ExecuteParameterSqlAsync(insertSql, new

            {

                JobId = 10,

                Email = "XX'TT",

                Name = "AA'BB",

                GaClientId = "GaClientId"

            });



            //關於查詢

            string name = "%'B%";

            //原生寫法

            var res1 = await dbct.ProfileEvents.FromSqlRaw("Select top 100 * from ProfileEvent where Name like @name",

                new object[]

                    {

                        new SqlParameter("@name", "%'B%")

                    })

                .ToListAsync();



            //擴充, object to SqlParameter array

            var res2 = await dbct.ProfileEvents.FromSqlRaw("Select top 100 * from ProfileEvent where Name like @name",

                new { name }.ToSqlParamsArray())

                .ToListAsync();



            var res3 = await dbct.ProfileEvents.FromSql($"Select top 100 * from ProfileEvent where Name like {name}")

                .ToListAsync();



            var res4 = await dbct.ProfileEvents.FromSqlInterpolated($"Select top 100 * from ProfileEvent where Name like {name}")

                .ToListAsync();



            return new { res1, res2, res3, res4 };

        }

More...

Bike, 2023/5/6 下午 05:37:19

Visual Studio DbContext Scaffold

關於Scaffold的參數，官網雖然有文件但不是很好找，因此在此紀錄一下。
(於PM Console輸入'dotnet ef dbcontext scaffold -h'也可以查看)

-d | --data-annotations : 使用屬性定義模型
-c | --context <NAME> : 產生的DbContext名稱
--context-dir <PATH> : 產生的DbContext位置
-f | --force : 覆寫現有檔案
-o | --output-dir <PATH> : 產生的Entity Model位置
--schema <SCHEMA_NAME1>, <SCHEMA_NAME2>... : 指定Schemas產生Entity
-t | --table <TABLE_NAME1>, <TABLE_NAME2>... : 指定Table產生Entity
--use-database-names : 強制使用DB中Table與Column Name
--json : 輸出Json格式資料表於PM Console
-n | --namespace <NAMESPACE> : 指定命名空間，預設會依照專案與資料夾命名
--context-namespace <NAMESPACE> : 指定DbContext命名空間，預設會依照專案與資料夾命名
--no-onconfiguring : 不產生DbContext中的OnConfiguring
--no-pluralize : 關閉自動複數判別
-p | --project <PROJECT> : 指定專案
-s | --startup-project <PROJECT> : 指定指令執行時起始專案
--framework <FRAMEWORK> : 指定框架版本
--configuration <CONFIGURATION> : 指定配置
--no-build : 跳過專案建置

More...

梨子, 2022/12/15 下午 12:12:11

Orable table lock soluiton

當發現於Developer下Script時，ScriptRunner一直在跑都不會停的時候，請先暫停該Query。

1. 查出哪隻Session將Table lock住了
select b.owner,b.object_name,a.session_id,a.locked_mode from v$locked_object a,dba_objects b where b.object_id = a.object_id;

2. 取得該Session SID與SERIAL#，順便可以看是哪個SQL帳號Lock的
select b.username,b.sid,b.serial#,logon_time from v$locked_object a,v$session b where a.session_id = b.sid order by b.logon_time;

3. 使用下面這段SQL，帶入SID與SERIAL#即可將該Session Kill
alter system kill session'{SID}, {SERIAL#}';

More...

梨子, 2022/10/26 下午 08:35:31

資料庫 where 條件要注意的兩件事

最近剛好發生跟 MS SQL 有關的狀況，所以就記錄一下

1. where 字串欄位要不要加 N'' (unicode)
範例: Select * from OrderDetail where OrderDetailId= N'20220923084533'
基本上，欄位是 char、varchar 就不需要。nvarchar nchar 就要加 N
這好像是廢話，但往往寫程式會沒注意，甚至是會覺得通通加 N 比較沒問題
但如果欄位牽涉到 index 就會影響搜尋，所以寫程式當下要注意

-- 假設 OrderDetailId 是 varchar(20)

-- OrderDetail 有千萬筆資料



Select * from OrderDetail where OrderDetailId= N'20220923084533'

-- 結果跑超級久 (未使用 PK 找，掃整個 table)

Select * from OrderDetail where OrderDetailId= '20220923084533'

-- 結果一下就出來 (使用 PK 找)

-- **資料庫設計最好以數值來當 key 比較好

2. 當欄位有 null 值，where [clumnName] not in ('A') 也會排除 null 的狀況
直覺上，只要下 not in (..) 那會其他項目都會抓出，但是實際上，該欄位是 null的資料也會被排除
因為資料庫一旦你對某欄位下條件，他就會排除 null 的欄位，除非你指定 [clumnName] is null 才會有資料

More...

darren, 2022/9/23 下午 04:06:22

PostgreSQL 的 monitor trigger

--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.

    }

}

More...

Bike, 2022/7/20 上午 10:05:39

資料存取架構比較 Entity Framework, Data Table, Dapper

比較方式: 對相同的資料表讀取 1000 次，來比較速度。
資料庫為 MS SQL

這裡做了 4 個 Case:

Case 1:
使用 Entity Framework，DbContext 為每次 new 一個。

Case 2:
使用 Entity Framework，使用同一個 DbContext。

Case 3:
用 DAO，轉為 Data Table 的格式 (使用 DtFromSql)。

Case 4:
使用 Dapper。

專案啟動時的記憶體使用量約為: 123 MB

測試一:
第一次讀取
Case 1, 時間: 3673.0303 ms, 記憶體: 566 MB

Case 2, 時間: 3889.9379 ms, 記憶體: 304 MB (這個時間有時會測試到 3000 ms)

Case 3, 時間: 1665.7748 ms, 記憶體: 205 MB

Case 4, 時間: 1639.7211 ms, 記憶體: 193 MB

讀取五次
Case 1, 時間: 1984.6395, 記憶體: 544MB (有發生 GC)

Case 2, 時間: 2367.9792 ms, 記憶體: 627 MB (沒有發生 GC)

Case 3, 時間: 1395.1132 ms, 記憶體: 280 MB (有發生 GC)

Case 4, 時間: 1531.3555 ms, 記憶體: 271 MB

結果: Dapper 看來完勝，速度上和直接使用 DAO 轉進 Data Table 的速度相近。但 Dapper 傳回的結果已經轉換為物件 List，操作上會更為方便。

Entity Framework 一如預期的較慢，且花費較多的記憶體。但和想像中最大的差異是，使用同一個 DbContext 比 new 1000 個 DbContext 的速度還要慢，花費的記憶體在 GC 之後，差異不大。

所以不一定要用 DI 注入 DbContext, 在各 function 中一直傳遞 DbContext. 在 Static 的 function 中，可以安心的 new 一個 DbContext 出來使用吧，只是要記得用 using 哦，否則可能會有 connection 沒有關閉的問題。

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Bike, 2022/7/18 上午 09:46:34