I have multiple json string lines. I loaded them as a DataFrame.
After merging data by Id, for an Id, all properties become arrays like:
{"id":123, "color":[A,B,C], "year":[1999], "nickname":[], "process":[[...]], ...}
I want to make this kind of json lines to:
{"id":123, "color":[A,B,C], "year":1999, "process":[...], ...} // deleting "nickname"
How can I do this?
Related
I want to retrieve data from an external nested JSON file on my seed.rb
The JSON looks like this:
{"people":[{"name":"John", "age":"23"}, {"name":"Jack", "age":"25"}]}
I saw a solution on GitHub but it only works on non-nested JSON.
Let's say you have JSON file db/seeds.json:
{"people":[{"name":"John", "age":"23"}, {"name":"Jack", "age":"25"}]}
You can use it like this in your db/seeds.rb:
seeds = JSON.parse(Rails.root.join("db", "seeds.json"), symbolize_names: true)
User.create(seeds[:people])
seeds[:people] in this case is array of hashes with user attributes
if you have:
json_data = {"people":[{"name":"John", "age":"23"}, {"name":"Jack", "age":"25"}]}
when you do:
json_data[:people]
you'll get an array:
[{:name=>"John", :age=>"23"}, {:name=>"Jack", :age=>"25"}]
if you want to use this array to populate a model, you can do:
People.create(json_data[:people])
if you want to read each item values, you can iterate through your data, like:
json_data[:people].each {|p| puts p[:name], p[:age]}
Many similar questions, but unfortunately non helped me solve my problem. I tried to && and #> and similar, but no success.
I have a postgres DB with a table, that has a "value" column typed "json". All rows have the same basic structure, a simple JSON object, with the att "value" holding an array of strings:
{
value: ['one', 'two', 'three']
}
I need to make a query accepting an array of strings and returns all the rows, in which the value array and the passed array of strings have at least one common element.
Following the upper example, if I send ['one', 'four'], it should return the row with value: ['one', 'two', 'three'], since there is an intersection - 'one'.
If I send the array ['four', 'five', 'six'], it will not return this row.
You can use the ?| operator for that. But as you are using json and not the recommended jsonb type, you need to cast your column:
select *
from the_table
where (value::jsonb -> 'value') ?| array['one', 'four']
I have wrote a code like below to concatenate two arrays together and save them as a JSON file.
In this code, "seg" is an array of some number, which has been produced somewhere in my code. info is also an array containing some data following by "Seg" array.
Defining variable types:
seg: Array<any> = [];
info: Array<any>=[];
final: Array<{info:any, Seg:any}>=[];
push value in array and concatenate them together:
this.info.push({date_created: 25 , description: 'aaa', year:'2015'});
this.final.push({info: this.info ,Seg:this.seg});
this.file.writeFile(this.file.externalApplicationStorageDirectory, 'test.json', JSON.stringify(this.final));
the produced file is something like this:
[{"info":[{"date_created: 25 , "description"="aaa", "year" :"2015"}],"seg":[2,3,4,5]}]
As you can see, the info information is placed between two bracket, so JSON file consider it as a list, not record.
Does anyone knows , how can I remove this brackets from the info array sides?
Should change the type of variable from array to anything else?
You can use like this to store as a record
seg: Array<any> = [];
info: Array<any>=[];
final:{info:any, Seg:any};
this.final.Seg = this.seg;
this.final.info = this.info;
The default output of JsonConvert.SerializeObject(ds2, Formatting.Indented) is an array of objects. I'd like to get an array of arrays with just the row data and not reapeating of the column name in each row.
I'd like to be able to present my recordset to DataTables as an array of columns and an array of row data items. Getting the column names into a variable is pretty easy and fast, but I'm wondering what's the fastest way to get the row data into an array.
I'm not interested in compressing the data in transit as described in another answer. The data needs to be processed on the client side in a jQuery DataTable. The more rows returned the slower the JavaScript gets.
To be clear, I want the JSON Serializer to return data in the following format:
aoColumns: [
"Name",
"Age",
"Location"
],
aaData: [
["Bob", 32, "Group1"],
["Sara", 43, "Group1"],
["Gary", 41, "Group2"]
]
aaData could be any name as DataTables can be told where to find the data and the column names.
I'm using Postgrex in Elixir, and when it returns query results, it returns them in the following struct format:
%{columns: ["id", "email", "name"], command: :select, num_rows: 2, rows: [{1, "me#me.com", "Bobbly Long"}, {6, "email#tts.me", "Woll Smoth"}]}
It should be noted I am using Postgrex directly WITHOUT Ecto.
The columns (table headers) are returned as a collection, but the results (rows) are returned as a list of tuples. (which seems odd, as they could get very large).
I'm trying to find the best way to programmatically create JSON objects for each result in which the JSON key is the column title and the JSON value the corresponding value from the tuple.
I've tried creating maps from both, merging and then serialising to JSON objects but it seems there should be an easier/better way of doing this.
Has anyone dealt with this before? What is the best way of creating a JSON object from a separate collection and tuple?
Something like this should work:
result = Postgrex.query!(...)
Enum.map(result.rows, fn row ->
Enum.zip(result.columns, Tuple.to_list(row))
|> Enum.into(%{})
|> JSON.encode
end)
This will result in a list of json objects where each row in the resultset is a json object.