explode
Description
This is a table function that is used in combination with Lateral View.
It converts an array column to multiple rows. If array
is null or empty, the returned explode_outer
part will be NULL. will return NULL. Bothexplode
and explode_outer
keep the nested NULL elements of array
.
Syntax:
explode(expr)
explode_outer(expr)
Example
mysql> set enable_vectorized_engine = true
mysql> select e1 from (select 1 k1) as t lateral view explode([1,2,3]) tmp1 as e1;
+------+
| e1 |
+------+
| 1 |
| 2 |
| 3 |
+------+
mysql> select e1 from (select 1 k1) as t lateral view explode_outer(null) tmp1 as e1;
+------+
| e1 |
+------+
| NULL |
+------+
mysql> select e1 from (select 1 k1) as t lateral view explode([]) tmp1 as e1;
Empty set (0.010 sec)
mysql> select e1 from (select 1 k1) as t lateral view explode([null,1,null]) tmp1 as e1;
+------+
| e1 |
+------+
| NULL |
| 1 |
| NULL |
+------+
mysql> select e1 from (select 1 k1) as t lateral view explode_outer([null,1,null]) tmp1 as e1;
+------+
| e1 |
+------+
| NULL |
| 1 |
| NULL |
+------+
Keywords
EXPLODE,EXPLODE_OUTER,ARRAY