Hello, I am having trouble flattening a json column into multiple rows. Is there an easy way to do with FlinkSQL:

id      json_column 
 1      {"k1": "v1", "k2": "v11"}
 2      {"k1": "v2", "k2": "v22"}

id        k1    k2 
 1      "v1"    "v11"   
 2      "v2"    "v22"

Or even more complex

id      json_column 
 1      {"k1": "v1", "k11": "v11"}
 2      {"k2": "v2", "k22": "v22"}

id          key      value
 1         "k1"       "v1"   
 1        "k11"      "v11"   
 2         "k2"       "v2" 
 2        "k22"      "v22"

Any ideas?

Have you looked into UDTFs(User Defined Table Functions)? https://nightlies.apache.org/flink/flink-docs-release-1.17/docs/dev/table/functions/udfs/#table-functions