SQL MongoDB

MongoDB

• What is MongoDB?
  It is a kind of NoSQL, no relation between tables.
  Java Script is for MongoDB’s query.

• Terminology on NoSQL

1. tables = collections
2. documents = records
3. create databases = use [database name]
4. query in MySQL = begin with Select but query in NoSQL = db.[collection name].find()
5. if there are some conditions about data, add the conditions in ().
6. operator begins with $.

• comparative operator:

1. $lt = < (less than), $lte = <= (less than and equal)
2. $gt = > (greater than), $gte = >= (greater than and equal)
3. $eq = = (is equal)

• logical operator: $or, $and, $not, $nor

1. function: begin with
   var [variance name] = function(~){
   formula
   return ~
   }
2. making an order = sort: 1 = asc, -1 = desc, .sort({column name: 1 or -1})
3. skip(#).limit(#) = limit #, # in MySQL

• please check the extra examples and the formula in depth on my Naver blog and Github blog!