explode-json-array-double-outer

---

{ "title": "EXPLODE_JSON_ARRAY_DOUBLE_OUTER", "language": "en" }

Description

The explode_json_array_double_outer table function accepts a JSON array. Its implementation logic is to convert the JSON array to an array type and then call the explode_outer function for processing. The behavior is equivalent to: explode_outer(cast(<json_array> as Array<DOUBLE>)). It should be used together with LATERAL VIEW.

Syntax

EXPLODE_JSON_ARRAY_DOUBLE_OUTER(<json>)

Parameters

• <json> JSON type, the content should be an array.

Return Value

• Returns a single-column, multi-row result composed of all elements in <json>. The column type is Nullable<DOUBLE>.
• If <json> is NULL or an empty array (number of elements is 0), 1 row with NULL is returned.
• If the elements in the JSON array are not of DOUBLE type, the function will try to convert them to DOUBLE. Elements that cannot be converted to DOUBLE will be converted to NULL. For type conversion rules, please refer to JSON Type Conversion.

Examples

0. Prepare data

   create table example(
       k1 int
   ) properties(
       "replication_num" = "1"
   );
   
   insert into example values(1);
1. Regular parameters

   select * from example lateral view explode_json_array_double_outer('[4, 5, 5.23, null]') t2 as c;

   +------+------+
   | k1   | c    |
   +------+------+
   |    1 |    4 |
   |    1 |    5 |
   |    1 | 5.23 |
   |    1 | NULL |
   +------+------+
2. DOUBLE type

   select * from example 
       lateral view 
       explode_json_array_double_outer('[123.445, 9223372036854775807.0, 9223372036854775808.0, -9223372036854775808.0, -9223372036854775809.0]') t2 as c;

   +------+------------------------+
   | k1   | c                      |
   +------+------------------------+
   |    1 |                123.445 |
   |    1 |  9.223372036854776e+18 |
   |    1 |  9.223372036854776e+18 |
   |    1 | -9.223372036854776e+18 |
   |    1 | -9.223372036854776e+18 |
   +------+------------------------+
3. Empty array

   select * from example lateral view explode_json_array_double_outer('[]') t2 as c;

   +------+------+
   | k1   | c    |
   +------+------+
   |    1 | NULL |
   +------+------+
4. NULL parameter

   select * from example lateral view explode_json_array_double_outer(NULL) t2 as c;

   +------+------+
   | k1   | c    |
   +------+------+
   |    1 | NULL |
   +------+------+
5. Non-array parameter

   select * from example lateral view explode_json_array_double_outer('{}') t2 as c;

   +------+------+
   | k1   | c    |
   +------+------+
   |    1 | NULL |
   +------+------+