Hi,
Flink SQL JSON format supports nested formats like the schema that you
posted. Maybe the renaming with `from()` works not as expected. Did you
try it without the `from()` where schema fields are equal to JSON fields?
Alternatively, you could also define the schema only and use the
`deriveSchema()` mode of the format.
Btw there is a big bug in the JSON format that could affect how rows are
parsed (https://issues.apache.org/jira/browse/FLINK-11727).
Maybe it is worth it to write your own format and perform the JSON
parsing logic how you would like it.
Regards,
Timo
Am 04.03.19 um 08:38 schrieb 杨光:
Hi,
i am trying the flink sql api to read json formate data from kafka topic.
My json schema is a nested json like this
{
"type": "object",
"properties": {
"table": {
"type": "string"
},
"str2": {
"type": "string"
},
"obj1": {
"type": "object",
"properties": {
"rkey": {
"type": "string"
},
"val": {
"type": "string"
},
"lastTime": {
"type": "number"
}
},
"required": ["lastTime", "rkey", "val"]
},
"obj2": {
"type": "object",
"properties": {
"val": {
"type": "string"
},
"lastTime": {
"type": "number"
}
},
"required": ["lastTime", "val"]
}
},
"required": ["table", "str2", "obj1", "obj2"]
}
i define a table sechema like this.
Schema schemaDesc1 = new Schema()
.......
.field("tablestr", Types.STRING).from("table")
.......
.field("rkey", Types.STRING).from("rkey");
when i run a debug case ,i got error about the "rkey" field (the file
in the nest obj1)
" SQL validation failed. Table field 'rkey' was resolved to
TableSource return type field 'rkey', but field 'rkey' was not found
in the return type Row".
My question is :does the org.apache.flink.table.descriptors.Json
format support nested json schema? If does ,how can i set the right
format or schema ? If not ,then how can i apply flink sql api on
nested json data source.
