StudentDb.sol

// SPDX-License-Identifier:MIT;
pragma solidity 0.8.0;




contract DB {
// 0xAb8483F64d9C6d1EcF9b849Ae677dD3315835cb2  //1
// 0x4B20993Bc481177ec7E8f571ceCaE8A9e22C02db  //2
// 0x78731D3Ca6b7E34aC0F824c42a7cC18A495cabaB //3
        address owner;
        struct Student{
            string name;
            uint256 age;
            uint256[] score;
        }

        mapping(address => Student) studentsDb;  // studentsDb[_address]
        string name;
        string symbol;
        uint8 decimal;

        constructor() {
            owner = msg.sender;
        }
        // admin === register && access their data;


            modifier onlyAdmin() {
                require(owner == msg.sender, "Only admin");
                _;
            }

            // register a student
        function InitRec(address _address, string memory _name, uint256 _age, uint256 _score) public  onlyAdmin{
            Student storage s = studentsDb[_address];
            s.name = _name;
            s.age = _age;
            s.score.push(_score);
        }

        // returns the data one a particular student

        function returnInit(address _address) public view returns (Student memory){
            return studentsDb[_address];
        }
// [0x1, 0x2] =>   student
        // returns the array of student info

        function returnArrayInit(address[] memory query) public view onlyAdmin returns  (Student[] memory c){
            c = new Student[](query.length);

            for(uint256 i=0; i < query.length; i++){
                c[i] = studentsDb[query[i]];
            }
        }



        // update the array of score

        function UpdateInitRec(address _address, uint256 _score) onlyAdmin public {
            Student storage s = studentsDb[_address];
                s.score.push(_score);
        }
 

}

// 0xAb8483F64d9C6d1EcF9b849Ae677dD3315835cb2

// 0x4B20993Bc481177ec7E8f571ceCaE8A9e22C02db

Thank you boss.

thank you for the code