{ “title”: “EXPLODE_JSON_OBJECT”, “language”: “en”, “description”: “The explodejsonobject table function expands a JSON object into multiple rows, each containing a key-value pair.” }

EXPLODE_JSON_OBJECT

Description

The explode_json_object table function expands a JSON object into multiple rows, each containing a key-value pair. It is commonly used to transform JSON objects into a more query-friendly format. This function only supports JSON objects with elements. It should be used together with LATERAL VIEW.

Syntax

EXPLODE_JSON_OBJECT(<json>)

Parameters

  • <json> JSON type, the content should be a JSON object.

Return Value

  • Returns a single-column, multi-row result composed of all elements in <json>. The column type is Nullable<Struct<String, JSON>>.
  • If <json> is NULL or not a JSON object (such as an array []), 0 rows are returned.
  • If <json> is an empty object (such as {}), 0 rows are returned.

Examples

  1. Prepare data
    create table example(
        k1 int
    ) properties(
        "replication_num" = "1"
    );
    
    insert into example values(1);
    
  2. Regular parameters
    select  * from example lateral view explode_json_object('{"k1": "v1", "k2": 123}') t2 as c;
    
    +------+------------------------------+
    | k1   | c                            |
    +------+------------------------------+
    |    1 | {"col1":"k1", "col2":""v1""} |
    |    1 | {"col1":"k2", "col2":"123"}  |
    +------+------------------------------+
    
  3. Expand key-value pairs into separate columns
    select  * from example lateral view explode_json_object('{"k1": "v1", "k2": 123}') t2 as k, v;
    
    +------+------+------+
    | k1   | k    | v    |
    +------+------+------+
    |    1 | k1   | "v1" |
    |    1 | k2   | 123  |
    +------+------+------+
    

    The type of v is JSON

  4. Empty object
    select  * from example lateral view explode_json_object('{}') t2 as c;
    
    Empty set (0.03 sec)
    
  5. NULL parameter
    select  * from example lateral view explode_json_object(NULL) t2 as c;
    
    Empty set (0.03 sec)
    
  6. Non-object parameter
    select  * from example lateral view explode_json_object('[]') t2 as c;
    
    Empty set (0.03 sec)