countequal

countequal

description

Syntax

BIGINT countequal(ARRAY<T> arr, T value)

判断数组中包含value元素的个数。返回结果如下：

num      - value在array中的数量；
0        - value不存在数组arr中；
NULL     - 如果数组为NULL。

example

mysql> select *, countEqual(c_array,5) from array_test;
+------+-----------------+--------------------------+
| id   | c_array         | countequal(`c_array`, 5) |
+------+-----------------+--------------------------+
|    1 | [1, 2, 3, 4, 5] |                        1 |
|    2 | [6, 7, 8]       |                        0 |
|    3 | []              |                        0 |
|    4 | NULL            |                     NULL |
+------+-----------------+--------------------------+
mysql> select *,countEqual(c_array, 1),countEqual(c_array, 5),countEqual(c_array, NULL) from array_test;
+------+-----------------------+--------------------------+--------------------------+-----------------------------+
| id   | c_array               | countequal(`c_array`, 1) | countequal(`c_array`, 5) | countequal(`c_array`, NULL) |
+------+-----------------------+--------------------------+--------------------------+-----------------------------+
|    1 | [1, 2, 3, 4, 5]       |                        1 |                        1 |                           0 |
|    2 | [6, 7, 8]             |                        0 |                        0 |                           0 |
|    3 | []                    |                        0 |                        0 |                           0 |
|    4 | NULL                  |                     NULL |                     NULL |                        NULL |
|    5 | [66, 77]              |                        0 |                        0 |                           0 |
|    5 | [66, 77]              |                        0 |                        0 |                           0 |
|    6 | NULL                  |                     NULL |                     NULL |                        NULL |
|    7 | [NULL, NULL, NULL]    |                        0 |                        0 |                           3 |
|    8 | [1, 2, 3, 4, 5, 5, 5] |                        1 |                        3 |                           0 |
+------+-----------------------+--------------------------+--------------------------+-----------------------------+

keywords

ARRAY,COUNTEQUAL