Representing a DB schema in JSON - json

Question

Let's say I have two tables in my database, employee and car defined thusly.
employee:
+--------------+------------+
| col_name | data_type |
+--------------+------------+
| eid | int |
| name | string |
| salary | int |
| destination | string |
+--------------+------------+
car:
+------------+----------------+
| col_name | data_type |
+------------+----------------+
| cid | int |
| name | string |
| model | string |
| cylinders | int |
| price | int |
+------------+----------------+
I would like to export this schema to a JSON object so that I can populate an HTML dropdown menu based on the table - for instance, the table menu would have employee and car. Selecting employee would populate another dropdown with the column names and types corresponding to that table.
Given this use case, would the optimal json representation of the database be this?
{
"employee": {
"salary": "int",
"destination": "string",
"eid": "int",
"name": "string"
},
"car": {
"price": "int",
"model": "string",
"cylinders": "int",
"name": "string",
"cid": "int"
}
}
EDIT:
Or would this be more appropriate?
{
"employee": [
{
"type": "int",
"colname": "eid"
},
{
"type": "string",
"colname": "name"
},
{
"type": "int",
"colname": "salary"
},
{
"type": "string",
"colname": "destination"
}
],
"car": [
{
"type": "int",
"colname": "cid"
},
{
"type": "string",
"colname": "name"
},
{
"type": "string",
"colname": "model"
},
{
"type": "int",
"colname": "cylinders"
},
{
"type": "int",
"colname": "price"
}
]
}

Answer 1

In the first example, all your data is stored in objects. Assuming the structure is stored in a var mytables, you can get the names with Object.keys(mytables), which returns ['employee', 'car']. Equivalent for the columns inside: Object.keys(mytables['employee'].cols) returns ['salary','destination','eid','name'].
In the second example I would suggest to also store the tables in an array as the columns, like
[name: 'employee',
cols: [ {
"type": "int",
"colname": "cid"
}, ...]
Then you can easily iterate over the arrays and get the names by accessing mytables[i].name
for (t in tables){
console.log(tables[t].name);
for (c in tables[t].cols)
console.log(" - ",tables[t].cols[c].colname, ": ", tables[t].cols[c].type);
}