| --- | |
| { | |
| "title": "EXPLODE_SPLIT", | |
| "language": "en", | |
| "description": "The explodesplit table function is used to split a string into multiple substrings according to the specified delimiter," | |
| } | |
| --- | |
| ## Description | |
| The `explode_split` table function is used to split a string into multiple substrings according to the specified delimiter, and expand each substring into a separate row. | |
| It should be used together with [`LATERAL VIEW`](../../../query-data/lateral-view.md) to flatten nested data structures into a standard flat table format. | |
| The main difference between `explode_split` and [`explode_split_outer`](./explode-split-outer.md) is how they handle null values. | |
| ## Syntax | |
| ```sql | |
| EXPLODE_SPLIT(<str>, <delimiter>) | |
| ``` | |
| ## Parameters | |
| - `<str>` String type, the string to be split. | |
| - `<delimiter>` String type, the delimiter. | |
| ## Return Value | |
| - Returns a column composed of the split substrings, with column type String. | |
| ## Usage Notes | |
| 1. If `<str>` is NULL, 0 rows are returned. | |
| 2. If `<str>` is an empty string ("") or cannot be split, 1 row is returned. | |
| 3. If `<delimiter>` is NULL, 0 rows are returned. | |
| 4. If `<delimiter>` is an empty string (""), `<str>` will be split by bytes([`SPLIT_BY_STRING`](../scalar-functions/string-functions/split-by-string.md)). | |
| ## 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_split("ab,cd,ef", ",") t2 as c; | |
| ``` | |
| ```text | |
| +------+------+ | |
| | k1 | c | | |
| +------+------+ | |
| | 1 | ab | | |
| | 1 | cd | | |
| | 1 | ef | | |
| +------+------+ | |
| ``` | |
| 2. Empty string and unsplittable cases | |
| ```sql | |
| select * from example lateral view explode_split("", ",") t2 as c; | |
| ``` | |
| ```text | |
| +------+------+ | |
| | k1 | c | | |
| +------+------+ | |
| | 1 | | | |
| +------+------+ | |
| ``` | |
| ```sql | |
| select * from example lateral view explode_split("abc", ",") t2 as c; | |
| ``` | |
| ```text | |
| +------+------+ | |
| | k1 | c | | |
| +------+------+ | |
| | 1 | abc | | |
| +------+------+ | |
| ``` | |
| 3. NULL parameter | |
| ```sql | |
| select * from example lateral view explode_split(NULL, ',') t2 as c; | |
| ``` | |
| ```text | |
| Empty set (0.03 sec) | |
| ``` | |
| 4. Empty delimiter | |
| ```sql | |
| select * from example lateral view explode_split('abc', '') t2 as c; | |
| ``` | |
| ```text | |
| +------+------+ | |
| | k1 | c | | |
| +------+------+ | |
| | 1 | a | | |
| | 1 | b | | |
| | 1 | c | | |
| +------+------+ | |
| ``` | |
| 5. Delimiter is NULL | |
| ```sql | |
| select * from example lateral view explode_split('abc', null) t2 as c; | |
| ``` | |
| ```text | |
| Empty set (0.03 sec) | |
| ``` |