Logtstash kv

Elastic Stack Logstash
1

I converted my mysql field value to kv using kv filter...

filter{
kv{
field_split => "&?"
}
}
but when i saw the result....it was in key and value form only...but in string codes...means my line break to kv form but in showing string...

So I am not able to call individual key and value....bcz its again become string...

Is there is any solution...after break string to kv form ....it index in kv form only..not a string..

2

What does the event/field look like?

3

Actually I want to send json after logstash fetch data from mysql in this form...
{
"group" : "fans",
"user" : [
{
"first" : "John",
"last" : "Smith"
},
{
"first" : "Alice",
"last" : "White"
}
]
}

But logstash makes each field of the mysql in seperate key valye form...
and then sending to elasticsearch..
But before send to elasticsearch I want to make my data in the above code way...Is there any possible way...