Bad Query? - Node.js

app.get("/user/:id", function (req, res) {
    connection.query("SELECT * FROM tbl_user WHERE id_user='" + req.params.id + "'", function(err, row, fields){
        connection.query("SELECT * FROM tbl_user_follow WHERE follower='" + req.params.id + "' AND following='" + req.cookies.idUser + "'", function(err, rowFollowStat, fields){
            connection.query("SELECT COUNT(follower) AS followerCount FROM tbl_user_follow WHERE follower='" + req.params.id + "'", function(err, rowFollower, fields){
                connection.query("SELECT COUNT(following) AS followingCount FROM tbl_user_follow WHERE following='" + req.params.id + "'", function(err, rowFollowing, fields){
                    var followStat = "";
                    var followUrl = "";

                    if (rowFollowStat.length > 0) {
                        followStat = "Unfollow";
                        followUrl = "/unfollow/" + row[0].id_user;
                    }else {
                        followStat = "Follow";
                        followUrl = "/follow/" + row[0].id_user;
                    }

                    res.render("user", {
                        title: "User",
                        name: row[0].username,
                        email: row[0].email,
                        followUrl: followUrl,
                        followStat: followStat,
                        follower: rowFollower[0].followerCount,
                        following: rowFollowing[0].followingCount
                    });
                });
            });
        });
    });
});