array_union
array_union
array_union
description
Syntax
ARRAY<T> array_union(ARRAY<T> array1, ARRAY<T> array2)
Returns an array of the elements in the union of array1 and array2, without duplicates. If the input parameter is null, null is returned.
notice
Only supported in vectorized engine
example
mysql> set enable_vectorized_engine=true;
mysql> select k1,k2,k3,array_union(k2,k3) from array_type_table;
+------+-----------------+--------------+-------------------------+
| k1 | k2 | k3 | array_union(`k2`, `k3`) |
+------+-----------------+--------------+-------------------------+
| 1 | [1, 2, 3] | [2, 4, 5] | [1, 2, 3, 4, 5] |
| 2 | [2, 3] | [1, 5] | [2, 3, 1, 5] |
| 3 | [1, 1, 1] | [2, 2, 2] | [1, 2] |
+------+-----------------+--------------+-------------------------+
mysql> select k1,k2,k3,array_union(k2,k3) from array_type_table_nullable;
+------+-----------------+--------------+-------------------------+
| k1 | k2 | k3 | array_union(`k2`, `k3`) |
+------+-----------------+--------------+-------------------------+
| 1 | [1, NULL, 3] | [1, 3, 5] | [1, NULL, 3, 5] |
| 2 | [NULL, NULL, 2] | [2, NULL, 4] | [NULL, 2, 4] |
| 3 | NULL | [1, 2, 3] | NULL |
+------+-----------------+--------------+-------------------------+
mysql> select k1,k2,k3,array_union(k2,k3) from array_type_table_varchar;
+------+----------------------------+----------------------------------+---------------------------------------------------+
| k1 | k2 | k3 | array_union(`k2`, `k3`) |
+------+----------------------------+----------------------------------+---------------------------------------------------+
| 1 | ['hello', 'world', 'c++'] | ['I', 'am', 'c++'] | ['hello', 'world', 'c++', 'I', 'am'] |
| 2 | ['a1', 'equals', 'b1'] | ['a2', 'equals', 'b2'] | ['a1', 'equals', 'b1', 'a2', 'b2'] |
| 3 | ['hasnull', NULL, 'value'] | ['nohasnull', 'nonull', 'value'] | ['hasnull', NULL, 'value', 'nohasnull', 'nonull'] |
| 4 | ['hasnull', NULL, 'value'] | ['hasnull', NULL, 'value'] | ['hasnull', NULL, 'value'] |
+------+----------------------------+----------------------------------+---------------------------------------------------+
mysql> select k1,k2,k3,array_union(k2,k3) from array_type_table_decimal;
+------+------------------+-------------------+----------------------------+
| k1 | k2 | k3 | array_union(`k2`, `k3`) |
+------+------------------+-------------------+----------------------------+
| 1 | [1.1, 2.1, 3.44] | [2.1, 3.4, 5.4] | [1.1, 2.1, 3.44, 3.4, 5.4] |
| 2 | [NULL, 2, 5] | [NULL, NULL, 5.4] | [NULL, 2, 5, 5.4] |
| 4 | [1, NULL, 2, 5] | [1, 3.1, 5.4] | [1, NULL, 2, 5, 3.1, 5.4] |
+------+------------------+-------------------+----------------------------+
keywords
ARRAY,UNION,ARRAY_UNION
