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How to create a paid keyvalue store

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3

I'd like to create a contract through which people can set publicly available key=value information in exchange for some Ether sent to me (the owner of the contract).
This is to create a public decentralized database on which anyone can read and write, and the Ether cost would be to limit spam.

However, I'd like it to be free for all users to retrieve any key stored in the contract. My understanding of Ethereum is limited, is this possible?

contract-development contract-design

share|improve this question

asked 1 hour ago

thewonderedthewondered

161

New contributor

thewondered is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

add a comment | 

3

I'd like to create a contract through which people can set publicly available key=value information in exchange for some Ether sent to me (the owner of the contract).
This is to create a public decentralized database on which anyone can read and write, and the Ether cost would be to limit spam.

However, I'd like it to be free for all users to retrieve any key stored in the contract. My understanding of Ethereum is limited, is this possible?

contract-development contract-design

share|improve this question

asked 1 hour ago

thewonderedthewondered

161

New contributor

thewondered is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

add a comment | 

I'd like to create a contract through which people can set publicly available key=value information in exchange for some Ether sent to me (the owner of the contract).
This is to create a public decentralized database on which anyone can read and write, and the Ether cost would be to limit spam.

However, I'd like it to be free for all users to retrieve any key stored in the contract. My understanding of Ethereum is limited, is this possible?

contract-development contract-design

share|improve this question

asked 1 hour ago

thewonderedthewondered

161

New contributor

thewondered is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

asked 1 hour ago

thewonderedthewondered

161

New contributor

thewondered is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

asked 1 hour ago

thewonderedthewondered

161

New contributor

thewondered is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked 1 hour ago

thewonderedthewondered

161

New contributor

thewondered is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked 1 hour ago

thewonderedthewondered

161

2 Answers
2

active

oldest

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2

I'd like to create a contract through which people can set publicly
available key=value information

You can use a mapping to store data and public method to set values

exchange for some Ether sent to me (the owner of the contract)

You can make the set method payable and check for an amount of Ether from sender

I'd like it to be free for all users to retrieve any key stored in the
contract

You can create the function a view one so no cost or transaction invlolved in reading values

is this possible?

Yes, This looks possible. It would look like below.

pragma solidity >=0.4.22 <0.6.0;



contract Store {

    mapping(bytes32 => bytes32) public keyValStore;

    address payable public  owner; 

    uint storeFee;



    constructor(uint fee) public {

        owner = msg.sender;  // setting contract creator address as the owner

        storeFee = fee; // setting a store fee for to set values

    }



    function set(bytes32 key, bytes32 value) public payable {

        require(msg.value >= storeFee); // check if Ether value is greater than the store fee

        owner.transfer(msg.value); // transfer Ether to owner account

        keyValStore[key] = value; // setting the key value pair in mapping

    }



    function get(bytes32 key) public view returns (bytes32) {

        bytes32 val = keyValStore[key]; // get the relavant value for the given key

        return val;

    }

}

share|improve this answer

edited 30 mins ago

answered 54 mins ago

Achala DissanayakeAchala Dissanayake

3,74481629

add a comment | 

0

Yes it's possible, here's an example key/value store contract to help you get started that requires 1 ether to set a key/value and anyone can read the data for free:

pragma solidity >=0.4.22 <0.6.0;

contract Store {

    mapping(bytes32 => bytes32) private store;

    mapping(bytes32 => address) private authors;

    address private owner;



    constructor() public {

        owner = msg.sender;

    }



    function set(bytes32 key, bytes32 value) public payable {

        require(msg.value == 1 ether);

        require(store[key] == 0 || authors[key] == msg.sender);

        store[key] = value;

        authors[key] = msg.sender;

    }



    function get(bytes32 key) public view returns(bytes32) {

        return store[key];

    }



    function withdraw(address payable receiver) public {

        require(msg.sender == owner);

        receiver.transfer(address(this).balance);

    }

}

https://rinkeby.etherscan.io/address/0xf7e0caef5cd7a18d31343670b60ff463fa23d5c8

share|improve this answer

edited 45 mins ago

answered 54 mins ago

Miguel MotaMiguel Mota

2,8421027

add a comment | 

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2

I'd like to create a contract through which people can set publicly
available key=value information

You can use a mapping to store data and public method to set values

exchange for some Ether sent to me (the owner of the contract)

You can make the set method payable and check for an amount of Ether from sender

I'd like it to be free for all users to retrieve any key stored in the
contract

You can create the function a view one so no cost or transaction invlolved in reading values

is this possible?

Yes, This looks possible. It would look like below.

pragma solidity >=0.4.22 <0.6.0;



contract Store {

    mapping(bytes32 => bytes32) public keyValStore;

    address payable public  owner; 

    uint storeFee;



    constructor(uint fee) public {

        owner = msg.sender;  // setting contract creator address as the owner

        storeFee = fee; // setting a store fee for to set values

    }



    function set(bytes32 key, bytes32 value) public payable {

        require(msg.value >= storeFee); // check if Ether value is greater than the store fee

        owner.transfer(msg.value); // transfer Ether to owner account

        keyValStore[key] = value; // setting the key value pair in mapping

    }



    function get(bytes32 key) public view returns (bytes32) {

        bytes32 val = keyValStore[key]; // get the relavant value for the given key

        return val;

    }

}

share|improve this answer

edited 30 mins ago

answered 54 mins ago

Achala DissanayakeAchala Dissanayake

3,74481629

add a comment | 

2

I'd like to create a contract through which people can set publicly
available key=value information

You can use a mapping to store data and public method to set values

exchange for some Ether sent to me (the owner of the contract)

You can make the set method payable and check for an amount of Ether from sender

I'd like it to be free for all users to retrieve any key stored in the
contract

You can create the function a view one so no cost or transaction invlolved in reading values

is this possible?

Yes, This looks possible. It would look like below.

pragma solidity >=0.4.22 <0.6.0;



contract Store {

    mapping(bytes32 => bytes32) public keyValStore;

    address payable public  owner; 

    uint storeFee;



    constructor(uint fee) public {

        owner = msg.sender;  // setting contract creator address as the owner

        storeFee = fee; // setting a store fee for to set values

    }



    function set(bytes32 key, bytes32 value) public payable {

        require(msg.value >= storeFee); // check if Ether value is greater than the store fee

        owner.transfer(msg.value); // transfer Ether to owner account

        keyValStore[key] = value; // setting the key value pair in mapping

    }



    function get(bytes32 key) public view returns (bytes32) {

        bytes32 val = keyValStore[key]; // get the relavant value for the given key

        return val;

    }

}

share|improve this answer

edited 30 mins ago

answered 54 mins ago

Achala DissanayakeAchala Dissanayake

3,74481629

add a comment | 

I'd like to create a contract through which people can set publicly
available key=value information

You can use a mapping to store data and public method to set values

exchange for some Ether sent to me (the owner of the contract)

You can make the set method payable and check for an amount of Ether from sender

I'd like it to be free for all users to retrieve any key stored in the
contract

You can create the function a view one so no cost or transaction invlolved in reading values

is this possible?

Yes, This looks possible. It would look like below.

pragma solidity >=0.4.22 <0.6.0;



contract Store {

    mapping(bytes32 => bytes32) public keyValStore;

    address payable public  owner; 

    uint storeFee;



    constructor(uint fee) public {

        owner = msg.sender;  // setting contract creator address as the owner

        storeFee = fee; // setting a store fee for to set values

    }



    function set(bytes32 key, bytes32 value) public payable {

        require(msg.value >= storeFee); // check if Ether value is greater than the store fee

        owner.transfer(msg.value); // transfer Ether to owner account

        keyValStore[key] = value; // setting the key value pair in mapping

    }



    function get(bytes32 key) public view returns (bytes32) {

        bytes32 val = keyValStore[key]; // get the relavant value for the given key

        return val;

    }

}

share|improve this answer

edited 30 mins ago

answered 54 mins ago

Achala DissanayakeAchala Dissanayake

3,74481629

pragma solidity >=0.4.22 <0.6.0;



contract Store {

    mapping(bytes32 => bytes32) public keyValStore;

    address payable public  owner; 

    uint storeFee;



    constructor(uint fee) public {

        owner = msg.sender;  // setting contract creator address as the owner

        storeFee = fee; // setting a store fee for to set values

    }



    function set(bytes32 key, bytes32 value) public payable {

        require(msg.value >= storeFee); // check if Ether value is greater than the store fee

        owner.transfer(msg.value); // transfer Ether to owner account

        keyValStore[key] = value; // setting the key value pair in mapping

    }



    function get(bytes32 key) public view returns (bytes32) {

        bytes32 val = keyValStore[key]; // get the relavant value for the given key

        return val;

    }

}

share|improve this answer

edited 30 mins ago

answered 54 mins ago

Achala DissanayakeAchala Dissanayake

3,74481629

answered 54 mins ago

Achala DissanayakeAchala Dissanayake

3,74481629

answered 54 mins ago

Achala DissanayakeAchala Dissanayake

3,74481629

0

Yes it's possible, here's an example key/value store contract to help you get started that requires 1 ether to set a key/value and anyone can read the data for free:

pragma solidity >=0.4.22 <0.6.0;

contract Store {

    mapping(bytes32 => bytes32) private store;

    mapping(bytes32 => address) private authors;

    address private owner;



    constructor() public {

        owner = msg.sender;

    }



    function set(bytes32 key, bytes32 value) public payable {

        require(msg.value == 1 ether);

        require(store[key] == 0 || authors[key] == msg.sender);

        store[key] = value;

        authors[key] = msg.sender;

    }



    function get(bytes32 key) public view returns(bytes32) {

        return store[key];

    }



    function withdraw(address payable receiver) public {

        require(msg.sender == owner);

        receiver.transfer(address(this).balance);

    }

}

https://rinkeby.etherscan.io/address/0xf7e0caef5cd7a18d31343670b60ff463fa23d5c8

share|improve this answer

edited 45 mins ago

answered 54 mins ago

Miguel MotaMiguel Mota

2,8421027

add a comment | 

0

Yes it's possible, here's an example key/value store contract to help you get started that requires 1 ether to set a key/value and anyone can read the data for free:

pragma solidity >=0.4.22 <0.6.0;

contract Store {

    mapping(bytes32 => bytes32) private store;

    mapping(bytes32 => address) private authors;

    address private owner;



    constructor() public {

        owner = msg.sender;

    }



    function set(bytes32 key, bytes32 value) public payable {

        require(msg.value == 1 ether);

        require(store[key] == 0 || authors[key] == msg.sender);

        store[key] = value;

        authors[key] = msg.sender;

    }



    function get(bytes32 key) public view returns(bytes32) {

        return store[key];

    }



    function withdraw(address payable receiver) public {

        require(msg.sender == owner);

        receiver.transfer(address(this).balance);

    }

}

https://rinkeby.etherscan.io/address/0xf7e0caef5cd7a18d31343670b60ff463fa23d5c8

share|improve this answer

edited 45 mins ago

answered 54 mins ago

Miguel MotaMiguel Mota

2,8421027

add a comment | 

Yes it's possible, here's an example key/value store contract to help you get started that requires 1 ether to set a key/value and anyone can read the data for free:

pragma solidity >=0.4.22 <0.6.0;

contract Store {

    mapping(bytes32 => bytes32) private store;

    mapping(bytes32 => address) private authors;

    address private owner;



    constructor() public {

        owner = msg.sender;

    }



    function set(bytes32 key, bytes32 value) public payable {

        require(msg.value == 1 ether);

        require(store[key] == 0 || authors[key] == msg.sender);

        store[key] = value;

        authors[key] = msg.sender;

    }



    function get(bytes32 key) public view returns(bytes32) {

        return store[key];

    }



    function withdraw(address payable receiver) public {

        require(msg.sender == owner);

        receiver.transfer(address(this).balance);

    }

}

https://rinkeby.etherscan.io/address/0xf7e0caef5cd7a18d31343670b60ff463fa23d5c8

share|improve this answer

edited 45 mins ago

answered 54 mins ago

Miguel MotaMiguel Mota

2,8421027

pragma solidity >=0.4.22 <0.6.0;

contract Store {

    mapping(bytes32 => bytes32) private store;

    mapping(bytes32 => address) private authors;

    address private owner;



    constructor() public {

        owner = msg.sender;

    }



    function set(bytes32 key, bytes32 value) public payable {

        require(msg.value == 1 ether);

        require(store[key] == 0 || authors[key] == msg.sender);

        store[key] = value;

        authors[key] = msg.sender;

    }



    function get(bytes32 key) public view returns(bytes32) {

        return store[key];

    }



    function withdraw(address payable receiver) public {

        require(msg.sender == owner);

        receiver.transfer(address(this).balance);

    }

}

share|improve this answer

edited 45 mins ago

answered 54 mins ago

Miguel MotaMiguel Mota

2,8421027

answered 54 mins ago

Miguel MotaMiguel Mota

2,8421027

answered 54 mins ago

Miguel MotaMiguel Mota

2,8421027