CS3402 Lecture 3

Posted 2020-10-23 Charonnnnn

JSON

javascript Object Notation (JSON)

• Serializing data objects 
• Human-readable
• Data Interchange
• Representing and storing semistructured data 

 

Base Values:

• Number, String, Boolean, etc

Objects ():

• Sets of label-value pairs (key-value pairs) 

Arrays []:

• List of values

{
"book": [

{

         "id":"01",
         "language": "Java",
         "edition": "third",
         "author": "Herbert Schildt"

}, {

　　　　　　"id":"07",
　　　　　　"language": "C++",
　　　　　　"edition": "second",
　　　　　　"author": "E.Balagurusamy"

}

]

}

Relational VS JSON

Relational JSON

• Collection of Tables

• Fixed Schema

• Simple expressive language

• Mature native systems 

JSON

• Collection of Nested Sets and Arrays 
• Schema not required in advance
• Not as simple
• Coupled with programming languages
  • Used in NOSQL systems anddoc-oriented DBMS 

 

JSON and PostgreSQL

 

 

Selecting

 

Filtering

 

 

Aggregation