I am building an application that I am dumping the data from one table into a json object. When I try to use this json object via angular I dont see the data. So I took the data from the json object and ran it in a parser and was told that there are too many characters in my json object. What is this limit?
Part 2, if this is the case, any ideas on how I could break up the data? Thanks
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I want to convert incoming JSON data from Kafka into a dataframe.
I am using structured streaming with Scala 2.12
Most people add a hard coded schema, but if the json can have additional fields, it requires changing the code base every-time, which is tedious.
One approach is to write it into a file and infer it with but I rather avoid doing that.
Is there any other way to approach this problem?
Edit: Found a way to turn a json string into a dataframe but cant extract it from the stream source, it is possible to extract it?
One way is to store the schema itself in the message headers (not in the key or value).
Though, this increases message size, it will be easy to parse the JSON value without the need for any external resource like a file or a schema registry.
New messages can have new schemas while at the same time old messages can still be processed using their old schema itself, because the schema is within the message itself.
Alternatively, you can version the schemas and include an id for every schema in the message headers (or) a magic byte in the key or value and infer the schema from there.
This approach is followed by Confluent Schema registry. It allows you to basically go through different versions of same schema and see how your schema has evolved over time.
Read the data as string and then convert it to map[string,String], this way you can process the any json without even knowing its schema
based on JavaTechnical answer , the best approach would be to use a schema registry and
avro data instead of json, there is no going around hardcoding a schema (for now).
include your schema name and id as a header and use them to read the schema from the schema registry.
use the from_avro fucntion to turn that data into a df!
I am working with a much larger JSON file than I am used too and I am getting confused on how to parse the file to extract an object.
resultJSON['BACSDocument']['Data'][0]['ARUDD'][0]['Advice'][0]['OriginatingAccountRecords'][0]['OriginatingAccountRecord'][0]['ReturnedDebitItem']
This is what I used to extract the "ReturnedDebitItem" array. I cannot use this as the json will come in different schemas but will always contain a "ReturnedDebitItem" so I need to parse the document.
I have tried using a couple of for loops but I am just receiving errors - any insight would be much appreciated. I am working with node but any pseudo code would also be helpful!
Hi is it possible to import any random json file into cassandra.
The json file is not exported from sstable2json. The json file is from a different website and needs to be imported into cassandra. Please could anyone advise whether this is possible
JSON support won't be introduced until Cassandra 3.0 (see CASSANDRA-7970) and in this case you still need to define a schema for your json data to map to. You do have some other options:
Use maps which sort of map to JSON. Maps can be indexed as of Cassandra 2.1 (CASSANDRA-4511) There is also a good Stack Exchange post about this.
You mention 'any random json file'. You could just have a string column that contains the raw JSON, but then you lose any query-ability of that data.
Come up with some kind of schema for your JSON data and map it to a CQL table and write some code that parses the JSON and writes it to the CQL table mapping to that data. This doesn't sound like an option for you since you want to be able to import any random JSON file.
If you are looking to only do json document storage, you might want to look at more document-oriented solutions instead of a column-oriented solution like cassandra.
I'm really at my wit's end here... I'm using VB-JSON Parser (http://www.ediy.co.nz/vbjson-json-parser-library-in-vb6-xidc55680.html) and I have the following array :
[{"timestamp":1410001952,"tid":2834225,"price":"483.77"}]
The documentation is really minimal and I have no clue whatsoever of how to access the array, been searching for several hours now on how to resolve this.
How can I get the "price" value? I know that i can use .item("price") when there is no array but I don't know what to do when there's an array and there is no name before it.
First have a look at Parsing JSON in Excel VBA
It explains the JScript way of parsing JSON string.
Browsing through the net, I found it really hard to get a complete VBA based JSON parser.
Some options are available in the VB version and then there are few online parsers who promise to parse JSON and convert them in Excel. These ones work fine with simple JSON data structure. But once you feed in a complex data set with nested arrays and structures, they simply fail.
Using JavaScript features of parsing JSON, on top of ScriptControl, we can create a parser in VBA which will list each and every data point inside the JSON. No matter how nested or complex the data structure is, as long as we provide a valid JSON, this parser will return a complete tree structure.
JavaScript’s Eval, getKeys and getProperty methods provide building blocks for validating and reading JSON.
Coupled with a recursive function in VBA we can iterate through all the keys (up to nth level) in a JSON string. Then using a Tree control (used in this article) or a dictionary or even on a simple worksheet, we can arrange the JSON data as required.
Here, you can find a complete VBA example.
There is a JSON serializer in .NET: http://msdn.microsoft.com/en-us/library/system.runtime.serialization.json
I am loading data from a mongodb collection to a mysql table through Kettle transformation.
First I extract them using MongodbInput and then I use json input step.
But since json input step has very low performance, I wanted to replace it with a
javacript script.
I am a beginner in Javascript and even though i tried somethings, the kettle javascript script is not recognizing any keywords.
can anyone give me sample code to convert Json data to different columns using javascript?
To solve your problem you need to see three aspects:
Reading from MongoDB
Reading from JSON
Reading from (probably) String
Reading from MongoDB Except if you changed the interface, MongoDB returns not JSON but BSON files (~binary JSON). You need to see the MongoDB documentation about reading and writing BSON: probably something like BSON.to() and BSON.from() but I don't know it by heart.
Reading from JSON Once you have your BSON in JSON format, you can read it using JSON.stringify() which returns a String.
Reading from (probably) String If you want to use the capabilities of JSON (why else would you use JSON?), you also want to use JSON.parse() which returns a JSON object.
My experience is that to send a JSON object from one step to the other, using a String is not a bad idea, i.e. at the end of a JavaScript step, you write your JSON object to a String and at the beginning of the next JavaScript step (can be further down the stream) you parse it back to JSON to work with it.
I hope this answers your question.
PS: writing JavaScript steps requires you to learn JavaScript. You don't have to be a master, but the basics are required. There is no way around it.
you could use the json input step to get the values of this json and put in common rows