explode
explode
description
表函数,需配合 Lateral View 使用。
将 array 列展开成多行。当 array 为NULL或者为空时,explode_outer
返回NULL。
explode
和 explode_outer
均会返回 array 内部的NULL元素。
syntax
explode(expr)
explode_outer(expr)
example
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