How can I access variables outside of the query function in node js

Question

var i = 5;
var userData = null;
for (let index = 1; index <= i; index++) {
    var sql = 'select * from sheet WHERE sheet_id ='+index;
    connect.query(sql, function(error, data, fiels){
        if(error){
            throw error;
        }else{
            userData = data;
            console.log(userData);
        }
    });
    console.log(userData);
}
console.log(userData);

I want to access userData every where. But I can access only inside the query function. Please help.