Github user myui commented on the issue: https://github.com/apache/incubator-hivemall/pull/135 ```sql select NAMED_STRUCT("Name", "John", "age", 31), to_json( NAMED_STRUCT("Name", "John", "age", 31) ), to_json( NAMED_STRUCT("Name", "John", "age", 31), array('Name', 'age') ), to_json( NAMED_STRUCT("Name", "John", "age", 31), array('name', 'age') ), to_json( NAMED_STRUCT("Name", "John", "age", 31), array('age') ), to_json( NAMED_STRUCT("Name", "John", "age", 31), array() ), to_json( null, array() ), to_json( struct("123", "456", 789, array(314,007)), array('ti','si','i','bi') ), to_json( struct("123", "456", 789, array(314,007)), 'ti,si,i,bi' ), to_json( struct("123", "456", 789, array(314,007)) ), to_json( NAMED_STRUCT("country", "japan", "city", "tokyo") ), to_json( NAMED_STRUCT("country", "japan", "city", "tokyo"), array('city') ), to_json( ARRAY( NAMED_STRUCT("country", "japan", "city", "tokyo"), NAMED_STRUCT("country", "japan", "city", "osaka") ) ), to_json( ARRAY( NAMED_STRUCT("country", "japan", "city", "tokyo"), NAMED_STRUCT("country", "japan", "city", "osaka") ), array('city') ); ``` > {"name":"John","age":31} {"name":"John","age":31} {"Name":"John","age":31} {"name":"John","age":31} {"age":31} {}NULL {"ti":"123","si":"456","i":789,"bi":[314,7]} {"ti":"123","si":"456","i":789,"bi":[314,7]} {"col1":"123","col2":"456","col3":789,"col4":[314,7]} {"country":"japan","city":"tokyo"} {"city":"tokyo"} [{"country":"japan","city":"tokyo"},{"country":"japan","city":"osaka"}] [{"country":"japan","city":"tokyo"},{"country":"japan","city":"osaka"}] ```sql select from_json( '{ "person" : { "name" : "makoto" , "age" : 37 } }', 'struct<name:string,age:int>', array('person') ), from_json( '[0.1,1.1,2.2]', 'array<double>' ), from_json(to_json( ARRAY( NAMED_STRUCT("country", "japan", "city", "tokyo"), NAMED_STRUCT("country", "japan", "city", "osaka") ) ),'array<struct<country:string,city:string>>'), from_json(to_json( ARRAY( NAMED_STRUCT("country", "japan", "city", "tokyo"), NAMED_STRUCT("country", "japan", "city", "osaka") ), array('city') ), 'array<struct<country:string,city:string>>'), from_json(to_json( ARRAY( NAMED_STRUCT("country", "japan", "city", "tokyo"), NAMED_STRUCT("country", "japan", "city", "osaka") ) ),'array<struct<city:string>>'); ``` > {"name":"makoto","age":37} [0.1,1.1,2.2] [{"country":"japan","city":"tokyo"},{"country":"japan","city":"osaka"}] [{"country":"japan","city":"tokyo"},{"country":"japan","city":"osaka"}] [{"city":"tokyo"},{"city":"osaka"}]
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