ARRAY_EXCEPT

Description

Returns an array of the elements in array1 but not in array2, without duplicates. If the input parameter is null, null is returned.

Syntax

ARRAY_EXCEPT(<arr1> , <arr2> )

Parameters

Parameter	Description
<arr1>	The source array arr1
<arr2>	An array of elements to compare with arr1

Return Value

Returns an array, Special cases：

• If the input parameter is null, null is returned.

Example

CREATE TABLE array_type_table (
    k1 INT,
    k2 ARRAY<INT>,
    k3 ARRAY<INT>
)
duplicate key (k1)
distributed by hash(k1) buckets 1
properties(
  'replication_num' = '1'
);
INSERT INTO array_type_table VALUES
(1, [1, 2, 3], [2, 4, 5]),
(2, [2, 3], [1, 5]),
(3, [1, 1, 1], [2, 2, 2]);
select k1,k2,k3,array_except(k2,k3) from array_type_table;

+------+-----------------+--------------+--------------------------+
| k1   | k2              | k3           | array_except(`k2`, `k3`) |
+------+-----------------+--------------+--------------------------+
|    1 | [1, 2, 3]       | [2, 4, 5]    | [1, 3]                   |
|    2 | [2, 3]          | [1, 5]       | [2, 3]                   |
|    3 | [1, 1, 1]       | [2, 2, 2]    | [1]                      |
+------+-----------------+--------------+--------------------------+

CREATE TABLE array_type_table_nullable (
    k1 INT,
    k2 ARRAY<INT>,
    k3 ARRAY<INT>
)
duplicate key (k1)
distributed by hash(k1) buckets 1
properties(
  'replication_num' = '1'
);
INSERT INTO array_type_table_nullable VALUES
(1, [1, NULL, 3], [1, 3, 5]),
(2, [NULL, NULL, 2], [2, NULL, 4]),
(3, NULL, [1, 2, 3]);
select k1,k2,k3,array_except(k2,k3) from array_type_table_nullable;

+------+-----------------+--------------+--------------------------+
| k1   | k2              | k3           | array_except(`k2`, `k3`) |
+------+-----------------+--------------+--------------------------+
|    1 | [1, NULL, 3]    | [1, 3, 5]    | [NULL]                   |
|    2 | [NULL, NULL, 2] | [2, NULL, 4] | []                       |
|    3 | NULL            | [1, 2, 3]    | NULL                     |
+------+-----------------+--------------+--------------------------+

CREATE TABLE array_type_table_varchar (
    k1 INT,
    k2 ARRAY<VARCHAR>,
    k3 ARRAY<VARCHAR>
)
    duplicate key (k1)
distributed by hash(k1) buckets 1
properties(
  'replication_num' = '1'
);
INSERT INTO array_type_table_varchar VALUES
(1, ['hello', 'world', 'c++'], ['I', 'am', 'c++']),
(2, ['a1', 'equals', 'b1'], ['a2', 'equals', 'b2']),
(3, ['hasnull', NULL, 'value'], ['nohasnull', 'nonull', 'value']),
(3, ['hasnull', NULL, 'value'], ['hasnull', NULL, 'value']);
select k1,k2,k3,array_except(k2,k3) from array_type_table_varchar;

+------+----------------------------+----------------------------------+----------------------+
| k1   | k2                         | k3                               | array_except(k2, k3) |
+------+----------------------------+----------------------------------+----------------------+
|    1 | ["hello", "world", "c++"]  | ["I", "am", "c++"]               | ["hello", "world"]   |
|    2 | ["a1", "equals", "b1"]     | ["a2", "equals", "b2"]           | ["a1", "b1"]         |
|    3 | ["hasnull", null, "value"] | ["hasnull", null, "value"]       | []                   |
|    3 | ["hasnull", null, "value"] | ["nohasnull", "nonull", "value"] | ["hasnull", null]    |
+------+----------------------------+----------------------------------+----------------------+

CREATE TABLE array_type_table_decimal (
    k1 INT,
    k2 ARRAY<DECIMAL(10, 2)>,
    k3 ARRAY<DECIMAL(10, 2)>
)
duplicate key (k1)
distributed by hash(k1) buckets 1
properties(
  'replication_num' = '1'
);
INSERT INTO array_type_table_decimal VALUES
(1, [1.1, 2.1, 3.44], [2.1, 3.4, 5.4]),
(2, [NULL, 2, 5], [NULL, NULL, 5.4]),
(1, [1, NULL, 2, 5], [1, 3.1, 5.4]);
select k1,k2,k3,array_except(k2,k3) from array_type_table_decimal;

+------+--------------------------+--------------------+----------------------+
| k1   | k2                       | k3                 | array_except(k2, k3) |
+------+--------------------------+--------------------+----------------------+
|    1 | [1.00, null, 2.00, 5.00] | [1.00, 3.10, 5.40] | [null, 2.00, 5.00]   |
|    1 | [1.10, 2.10, 3.44]       | [2.10, 3.40, 5.40] | [1.10, 3.44]         |
|    2 | [null, 2.00, 5.00]       | [null, null, 5.40] | [2.00, 5.00]         |
+------+--------------------------+--------------------+----------------------+