I am using JOLTTransformJson Processor in Nifi.
My input is:
[
{
"col_name": "time",
"data_type": "timestamp",
"is_nullable": true
},
{
"col_name": "otherData",
"data_type": "string",
"is_nullable": false
}
]
I am using the below spec:
[
{
"operation": "shift",
"spec": {
"*": {
"col_name": "name",
"data_type": "type[0]",
"is_nullable": {
"true": "type[1]",
"false": "type[1]"
}
}
}
},
{
"operation": "default",
"spec": {
"*": {
"type[1]": "notnull"
}
}
}
]
Expected Output is :
{
"type": "record",
"name": "table_name",
"fields": [
{
"name": "time",
"type": [
"timestamp",
"null"
]
},
{
"name": "otherData",
"type": [
"string",
"notnull"
]
}
]
}
But getting the below one as the current result by combining all values in array like:
{
"name": [
"time",
"otherData"
],
"type": [
[
"timestamp",
"int"
],
null
]
}
Can someone please help what am I missing.
You can use the following first shift transformation spec through walking by the objects of the array in order to be able to repeatedly apply the techniques :
[
{
"operation": "shift",
"spec": {
"#record": "type", // fixed values formed by using # wildcards left-hand-side
"#table_name": "name",
"*": {
"col_*": "fields[#2].&(0,1)", // replicate the 1st replacement of the asterisk from the current(0th) level
"is_nullable": { // conditional logic starts here
"@(1,data_type)": "fields[#3].type",
"true": {
"#null": "fields[#4].type"
},
"false": {
"#notnull": "fields[#4].type"
}
}
}
}
},
{ //to sort the attributes within the fields array
"operation": "sort",
"spec": {
"fields": ""
}
},
{ //to sort whole result
"operation": "shift",
"spec": {
"type": "&",
"name": "&",
"fields": "&"
}
}
]
the second and third transformation are just added to sort the attributes/arrays as desired