Csc 8711, Databases and the Web - Project 3

Due: Wednesday, March 13th
Individual Assignment.

JSON Parsing

Consider the concept of a complex attribute in the Entity-Relationship data model. A brief definition and explanation is given here. We will consider a JSON coding of complex attributes, as explained below:

• (complex) attributes are either simple or composite
• simple attributes are described in json as follows:

  { "name": "c", 
    "cardinality": "1", 
    "simple": "integer"
  }
  

  where "name" is the name of the attribute, "cardinality" is either "1" or "n", and "simple" contains the data type ("integer" or "string")
• composite attributes are described in json as follows:

  { "name": "b", 
    "cardinality": "1", 
    "composite": [
      { "name": "c",
        "cardinality": "1",
        "simple": "integer"
      },
      { "name": "d",
        "cardinality": "1",
        "simple": "string"
      }
    ]
  }
  

  where "name" and "cardinality" are as before; "composite" contains a list of sub-attributes, each of which may be simple or composite (recursive!)

Some examples of attribute schema and corresponding instance files are shown in the following examples:

• schema1.json, instance11.json, instance12.json.
• schema2.json, instance21.json, instance22.json, instance23.json.
• schema3.json, instance31.json.

1. Write an JSON Schema specification for the complex attribute schema documents.
2. Write a Python program (application) that parses JSON schema and instance files for complex attributes to validate a complex attribute instance document against a complex attribute schema document. You should accept the json files as command line arguments as shown below:

   $python3 CAValidator.py schema3.json instance32.json
   instance32 conforms to schema in schema3
   or
   instance32 does not conform to schema in schema3
   (error message??)