| --- |
| { |
| "title": "EXPLODE_JSON_ARRAY_JSON_OUTER", |
| "language": "en" |
| } |
| --- |
| |
| ## Description |
| The `explode_json_array_json_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<JSON>))`. |
| It should be used together with [`LATERAL VIEW`](../../../query-data/lateral-view.md). |
| |
| ## Syntax |
| ```sql |
| EXPLODE_JSON_ARRAY_JSON_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<JSON>`. |
| - If `<json>` is NULL or an empty array (number of elements is 0), 1 row with NULL is returned. |
| |
| ## Examples |
| 0. Prepare data |
| ```sql |
| create table example( |
| k1 int |
| ) properties( |
| "replication_num" = "1" |
| ); |
| |
| insert into example values(1); |
| ``` |
| 1. Regular parameters |
| ```sql |
| select * from example lateral view explode_json_array_json_outer('[4, "abc", {"key": "value"}, 5.23, null]') t2 as c; |
| ``` |
| ```text |
| +------+-----------------+ |
| | k1 | c | |
| +------+-----------------+ |
| | 1 | 4 | |
| | 1 | "abc" | |
| | 1 | {"key":"value"} | |
| | 1 | 5.23 | |
| | 1 | NULL | |
| +------+-----------------+ |
| ``` |
| 2. Empty array |
| ```sql |
| select * from example lateral view explode_json_array_json_outer('[]') t2 as c; |
| ``` |
| ```text |
| +------+------+ |
| | k1 | c | |
| +------+------+ |
| | 1 | NULL | |
| +------+------+ |
| ``` |
| 3. NULL parameter |
| ```sql |
| select * from example lateral view explode_json_array_json_outer(NULL) t2 as c; |
| ``` |
| ```text |
| +------+------+ |
| | k1 | c | |
| +------+------+ |
| | 1 | NULL | |
| +------+------+ |
| ``` |
| 4. Non-array parameter |
| ```sql |
| select * from example lateral view explode_json_array_json_outer('{}') t2 as c; |
| ``` |
| ```text |
| +------+------+ |
| | k1 | c | |
| +------+------+ |
| | 1 | NULL | |
| +------+------+ |
| ``` |