Solidity example code for getting volume data from CoinGecko via Band Protocol's OpenAPI

CoinGeckoVolumeDemo.sol

pragma solidity ^0.5.0;

interface Oracle {
  enum QueryStatus { INVALID, OK, NOT_AVAILABLE, DISAGREEMENT }
  function query(bytes calldata input)
    external payable returns (bytes32 output, uint256 updatedAt, QueryStatus status);
  function queryPrice() external view returns (uint256);
}

contract CoinGeckoVolumeContract {
  bytes public queryKey = hex"12202ac5043a71c56f6633403905f748302c8d9ca12f695e2b6de8c20e2f05ab10fe";
  uint256 public volume;

  function update(bytes memory coinId) public payable {
    Oracle oracle = Oracle(0x7f525974d824a6C4Efd54b9E7CB268eBEFc94aD8);
    
    uint256 queryPrice = oracle.queryPrice();
    require (address(this).balance >= queryPrice, "INSUFFICIENT_BALANCE_FOR_QUERY_FEE");
    
    (bytes32 raw, , Oracle.QueryStatus status) = oracle.query.value(queryPrice)(abi.encodePacked(queryKey, coinId));
            
    require(status == Oracle.QueryStatus.OK, "INVALID_QUERY_STATUS");
    
    volume = uint256(raw);
  }
}