Solidity: Contract should be marked as abstract

Question

I am trying to write a Smart Contract to generate Staking Rewards for an existing Cryptocurrency But I've been getting this error

Contract "Stakeable" should be marked as abstract

How do I fix this?

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.12;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
// import "@openzeppelin/contracts/access/Ownable.sol";
// import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
contract Stakeable is ERC20, Ownable{
        using SafeMath for uint256;
    
        string private constant _name = "Schrodinger";
        string private constant _symbol = "Kitty Dinger";
        
        /**
        * @notice We usually require to know who are all the stakeholders.
        */
        address[] internal stakeholders;
    
        /**
         * @notice The stakes for each stakeholder.
         */
        mapping(address => uint256) internal stakes;
    
        /**
         * @notice The accumulated rewards for each stakeholder.
         */
        mapping(address => uint256) internal rewards;
    
        /**
        * @notice The constructor for the Staking Token.
        * @param _owner The address to receive all tokens on construction.
        * @param _supply The amount of tokens to mint on construction.
        */
    
        constructor(string memory name_, string memory symbol_, address _owner, uint256 _supply)
        {    
            name_ = _name;
            symbol_ = _symbol;
            _mint(_owner, _supply);
        }

Answer 1

@ashhanai has a good point.

You are inheriting your contract from ERC20 but you didn't call the ERC20 constructor. If you'll update your constructor as like @ashhanai's suggestion, probably the problem will disappear.

Answer 2

Don't set the name and symbol properties directly, add call to ERC20 constructor instead.

Update constructor code:

constructor(string memory name_, string memory symbol_, address _owner, uint256 _supply) ERC20(name_, symbol_)
    {    
        _mint(_owner, _supply);
    }