Month: October 2016

CSS media Query

if screen width is less than 768px use this custom style:

#loginBody {
  width: 600px;
  height: 400px;
  margin-top: 100px;
  border-radius: 25px;
  background: rgb(238, 238, 238);
  background: -moz-linear-gradient(left, rgba(238, 238, 238, 1) 0%, #f8f8f8 100%);
  background: -webkit-linear-gradient(left, rgba(238, 238, 238, 1) 0%, #f8f8f8 100%);
  background: linear-gradient(to right, rgba(238, 238, 238, 1) 0%, #f8f8f8 100%);

  @media screen and (max-width: 768px) {
    width: 300px;
    height: 300px;
  }
}

http://www.w3schools.com/cssref/css3_pr_mediaquery.asp
http://www.w3schools.com/css/css_rwd_mediaqueries.asp
http://www.w3schools.com/css/css3_mediaqueries_ex.asp
http://www.w3schools.com/bootstrap/bootstrap_grid_system.asp

how to get the last N records in MongoDB

.sort()

db.foo.find().sort({x:1});

The 1 will sort ascending (oldest to newest) and -1 will sort descending (newest to oldest.)

If you use the auto created _id field it has a date embedded in it … so you can use that to order by …

db.foo.find().sort({_id:1});

That will return back all your documents sorted from oldest to newest.

Natural Order

You can also use a Natural Order mentioned above …

db.foo.find().sort({$natural:1});

Again, using 1 or -1 depending on the order you want.

Use .limit()

Lastly, it’s good practice to add a limit when doing this sort of wide open query so you could do either …

db.foo.find().sort({_id:1}).limit(50);

or

db.foo.find().sort({$natural:1}).limit(50);

References
http://stackoverflow.com/questions/4421207/mongodb-how-to-get-the-last-n-records

Install MongoDB on OpenSuse

after install run

sudo nano /etc/mongodb.conf
disable security
# Security settings.
#security:
#  authorization: enabled

the restart service and run with config

mongod --config /etc/mongodb.conf

other commands

db.createUser(
  {
    user: "admin",
    pwd: "admin",
    roles: [ { role: "root", db: "admin" } ]
  }
);
db.createUser(
    {
      user: "mahmood",
      pwd: "12345",
      roles: ["readWrite"]
    }
);

References
https://docs.mongodb.com/v3.0/reference/configuration-options/
http://stackoverflow.com/questions/23943651/mongodb-admin-user-not-authorized
http://stackoverflow.com/questions/35881662/mongodb-error-not-authorized-to-execute-command
https://docs.mongodb.com/manual/tutorial/enable-authentication/
http://stackoverflow.com/questions/23003391/how-do-i-add-an-admin-user-to-mongo-in-2-6