> use db1
switched to db db1

> show dbs
admin   0.000GB
config  0.000GB
local   0.000GB

> db.stats()
{
        "db" : "db1",
        "collections" : 0,
        "views" : 0,
        "objects" : 0,
        "avgObjSize" : 0,
        "dataSize" : 0,
        "storageSize" : 0,
        "totalSize" : 0,
        "indexes" : 0,
        "indexSize" : 0,
        "scaleFactor" : 1,
        "fileSize" : 0,
        "fsUsedSize" : 0,
        "fsTotalSize" : 0,
        "ok" : 1
}

> db.dropDatabase()
{ "ok" : 1 }

>mongo
MongoDB shell version v5.0.2
connecting to: mongodb://127.0.0.1:27017/?compressors=disabled&gssapiServiceName=mongodb
Implicit session: session { "id" : UUID("958c42c1-e0fe-45ec-b53e-d1a0db49c950") }
MongoDB server version: 5.0.2
================
Warning: the "mongo" shell has been superseded by "mongosh",
which delivers improved usability and compatibility.The "mongo" shell has been deprecated and will be removed in
an upcoming release.
We recommend you begin using "mongosh".
For installation instructions, see
https://docs.mongodb.com/mongodb-shell/install/
================
Welcome to the MongoDB shell.
For interactive help, type "help".
For more comprehensive documentation, see
        https://docs.mongodb.com/
Questions? Try the MongoDB Developer Community Forums
        https://community.mongodb.com
---
The server generated these startup warnings when booting:
        2021-08-14T09:24:46.540+09:00: Access control is not enabled for the database. Read and write access to data and configuration is unrestricted
---
---
        Enable MongoDB's free cloud-based monitoring service, which will then receive and display
        metrics about your deployment (disk utilization, CPU, operation statistics, etc).

        The monitoring data will be available on a MongoDB website with a unique URL accessible to you
        and anyone you share the URL with. MongoDB may use this information to make product
        improvements and to suggest MongoDB products and deployment options to you.

        To enable free monitoring, run the following command: db.enableFreeMonitoring()
        To permanently disable this reminder, run the following command: db.disableFreeMonitoring()
---
> 

>pip install pymongo
Collecting pymongo
  Downloading pymongo-3.12.0-cp38-cp38-win_amd64.whl (397 kB)
     |████████████████████████████████| 397 kB 6.8 MB/s
Installing collected packages: pymongo
Successfully installed pymongo-3.12.0

pragma solidity ^0.4.11;
contract MarketPlaceOverflow {
    address public owner;
    uint public stockQuantity;

    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    /// 追加在庫数を表示するイベント
    event AddStock(uint _addedQuantity);
            
    /// コンストラクタ
    function MarketPlaceOverflow() {
        owner = msg.sender;
        stockQuantity = 0;          // 最大値をチェックするため100を0に変更
    }

    /// 在庫の追加処理
    function addStock(uint _addedQuantity) public onlyOwner {
        // オーバーフローチェック
        require(stockQuantity + _addedQuantity > stockQuantity);

        AddStock(_addedQuantity);
        stockQuantity += _addedQuantity;
    }
}

pragma solidity ^0.4.11;
contract MarketPlaceOverflow {
    address public owner;
    uint public stockQuantity;    // 在庫数  改善２ uint8 ⇒ uint

    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    /// 追加在庫数を表示するイベント
    event AddStock(uint _addedQuantity);   // 改善２ uint8 ⇒ uint
            
    /// コンストラクタ
    function MarketPlaceOverflow() {
        owner = msg.sender;
        stockQuantity = 100;
    }

    /// 在庫の追加処理
    function addStock(uint _addedQuantity) public onlyOwner {  // 改善２ uint8 ⇒ uint
        // オーバーフローチェック
        require(stockQuantity + _addedQuantity > stockQuantity);    // 改善１

        AddStock(_addedQuantity);
        stockQuantity += _addedQuantity;
    }
}

pragma solidity ^0.4.11;
contract MarketPlaceOverflow {
    address public owner;
    uint8 public stockQuantity;    // 在庫数

    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    /// 追加在庫数を表示するイベント
    event AddStock(uint8 _addedQuantity);
            
    /// コンストラクタ
    function MarketPlaceOverflow() {
        owner = msg.sender;
        stockQuantity = 100;
    }

    /// 在庫の追加処理
    function addStock(uint8 _addedQuantity) public onlyOwner {
        // オーバーフローチェック
        require(stockQuantity + _addedQuantity > stockQuantity);    // 改善１

        AddStock(_addedQuantity);
        stockQuantity += _addedQuantity;
    }
}

pragma solidity ^0.4.11;
contract MarketPlaceOverflow {
    address public owner;
    uint8 public stockQuantity;    // 在庫数

    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }

    /// 追加在庫数を表示するイベント
    event AddStock(uint8 _addedQuantity);
            
    /// コンストラクタ
    function MarketPlaceOverflow() {
        owner = msg.sender;
        stockQuantity = 100;
    }

    /// 在庫の追加処理
    function addStock(uint8 _addedQuantity) public onlyOwner {
        AddStock(_addedQuantity);
        stockQuantity += _addedQuantity;
    }
}

> eth.getTransaction('0xd34e1aa86318225a66a77399f95a835b250ac75139c1c01eb2a80d3636238939').input
"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"

> web3.toAscii("0x74657374")
"test"

> eth.getTransaction('0x1bf2c055abc6e5d0f861c64c52c7a84419c4b80a41edbf954bce7c78b4147392').input
"0x7ed6c926000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000076b6f757368696e00000000000000000000000000000000000000000000000000"

> web3.toAscii("0x6b6f757368696e")
"koushin"