---
{
    "title": "ARRAY_MAP",
    "language": "en"
}
---

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## array_map

array_map(lambda,array,....)

### description

#### Syntax
`ARRAY<T> array_map(lambda, ARRAY<T> array1, ARRAY<T> array2)`

Use a lambda expression as the input parameter to calculate the corresponding expression for the internal data of other input ARRAY parameters.
The number of parameters entered in the lambda expression is 1 or more, which must be consistent with the number of input array columns.
The scalar functions can be executed in lambda, and aggregate functions are not supported.

```
array_map(x->x, array1);
array_map(x->(x+2), array1);
array_map(x->(abs(x)-2), array1);

array_map((x,y)->(x = y), array1, array2);
array_map((x,y)->(power(x,2)+y), array1, array2);
array_map((x,y,z)->(abs(x)+y*z), array1, array2, array3);
```

### example

```shell

mysql [test]>select *, array_map(x->x,[1,2,3]) from array_test2 order by id;
+------+-----------------+-------------------------+----------------------------------------+
| id   | c_array1        | c_array2                | array_map([x] -> x(0), ARRAY(1, 2, 3)) |
+------+-----------------+-------------------------+----------------------------------------+
|    1 | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [1, 2, 3]                              |
|    2 | [6, 7, 8]       | [10, 12, 13]            | [1, 2, 3]                              |
|    3 | [1]             | [-100]                  | [1, 2, 3]                              |
|    4 | NULL            | NULL                    | [1, 2, 3]                              |
+------+-----------------+-------------------------+----------------------------------------+
4 rows in set (0.02 sec)

mysql [test]>select *, array_map(x->x+2,[1,2,3]) from array_test2 order by id;
+------+-----------------+-------------------------+--------------------------------------------+
| id   | c_array1        | c_array2                | array_map([x] -> x(0) + 2, ARRAY(1, 2, 3)) |
+------+-----------------+-------------------------+--------------------------------------------+
|    1 | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [3, 4, 5]                                  |
|    2 | [6, 7, 8]       | [10, 12, 13]            | [3, 4, 5]                                  |
|    3 | [1]             | [-100]                  | [3, 4, 5]                                  |
|    4 | NULL            | NULL                    | [3, 4, 5]                                  |
+------+-----------------+-------------------------+--------------------------------------------+
4 rows in set (0.02 sec)

mysql [test]>select c_array1, c_array2, array_map(x->x,[1,2,3]) from array_test2 order by id;
+-----------------+-------------------------+----------------------------------------+
| c_array1        | c_array2                | array_map([x] -> x(0), ARRAY(1, 2, 3)) |
+-----------------+-------------------------+----------------------------------------+
| [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [1, 2, 3]                              |
| [6, 7, 8]       | [10, 12, 13]            | [1, 2, 3]                              |
| [1]             | [-100]                  | [1, 2, 3]                              |
| NULL            | NULL                    | [1, 2, 3]                              |
+-----------------+-------------------------+----------------------------------------+
4 rows in set (0.01 sec)

mysql [test]>select c_array1, c_array2, array_map(x->power(x,2),[1,2,3]) from array_test2 order by id;
+-----------------+-------------------------+----------------------------------------------------+
| c_array1        | c_array2                | array_map([x] -> power(x(0), 2.0), ARRAY(1, 2, 3)) |
+-----------------+-------------------------+----------------------------------------------------+
| [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [1, 4, 9]                                          |
| [6, 7, 8]       | [10, 12, 13]            | [1, 4, 9]                                          |
| [1]             | [-100]                  | [1, 4, 9]                                          |
| NULL            | NULL                    | [1, 4, 9]                                          |
+-----------------+-------------------------+----------------------------------------------------+

mysql [test]>select c_array1, c_array2, array_map((x,y)->x+y,c_array1,c_array2) from array_test2 order by id;
+-----------------+-------------------------+----------------------------------------------------------+
| c_array1        | c_array2                | array_map([x, y] -> x(0) + y(1), `c_array1`, `c_array2`) |
+-----------------+-------------------------+----------------------------------------------------------+
| [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [11, 22, -37, 84, -95]                                   |
| [6, 7, 8]       | [10, 12, 13]            | [16, 19, 21]                                             |
| [1]             | [-100]                  | [-99]                                                    |
| NULL            | NULL                    | NULL                                                     |
+-----------------+-------------------------+----------------------------------------------------------+
4 rows in set (0.02 sec)

mysql [test]>select c_array1, c_array2, array_map((x,y)->power(x,2)+y,c_array1, c_array2) from array_test2 order by id;
+-----------------+-------------------------+----------------------------------------------------------------------+
| c_array1        | c_array2                | array_map([x, y] -> power(x(0), 2.0) + y(1), `c_array1`, `c_array2`) |
+-----------------+-------------------------+----------------------------------------------------------------------+
| [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [11, 24, -31, 96, -75]                                               |
| [6, 7, 8]       | [10, 12, 13]            | [46, 61, 77]                                                         |
| [1]             | [-100]                  | [-99]                                                                |
| NULL            | NULL                    | NULL                                                                 |
+-----------------+-------------------------+----------------------------------------------------------------------+
4 rows in set (0.03 sec)

mysql [test]>select *,array_map(x->x=3,c_array1) from array_test2 order by id;
+------+-----------------+-------------------------+----------------------------------------+
| id   | c_array1        | c_array2                | array_map([x] -> x(0) = 3, `c_array1`) |
+------+-----------------+-------------------------+----------------------------------------+
|    1 | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [0, 0, 1, 0, 0]                        |
|    2 | [6, 7, 8]       | [10, 12, 13]            | [0, 0, 0]                              |
|    3 | [1]             | [-100]                  | [0]                                    |
|    4 | NULL            | NULL                    | NULL                                   |
+------+-----------------+-------------------------+----------------------------------------+
4 rows in set (0.02 sec)

mysql [test]>select *,array_map(x->x>3,c_array1) from array_test2 order by id;
+------+-----------------+-------------------------+----------------------------------------+
| id   | c_array1        | c_array2                | array_map([x] -> x(0) > 3, `c_array1`) |
+------+-----------------+-------------------------+----------------------------------------+
|    1 | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [0, 0, 0, 1, 1]                        |
|    2 | [6, 7, 8]       | [10, 12, 13]            | [1, 1, 1]                              |
|    3 | [1]             | [-100]                  | [0]                                    |
|    4 | NULL            | NULL                    | NULL                                   |
+------+-----------------+-------------------------+----------------------------------------+
4 rows in set (0.02 sec)

mysql [test]>select *,array_map((x,y)->x>y,c_array1,c_array2) from array_test2 order by id;
+------+-----------------+-------------------------+----------------------------------------------------------+
| id   | c_array1        | c_array2                | array_map([x, y] -> x(0) > y(1), `c_array1`, `c_array2`) |
+------+-----------------+-------------------------+----------------------------------------------------------+
|    1 | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [0, 0, 1, 0, 1]                                          |
|    2 | [6, 7, 8]       | [10, 12, 13]            | [0, 0, 0]                                                |
|    3 | [1]             | [-100]                  | [1]                                                      |
|    4 | NULL            | NULL                    | NULL                                                     |
+------+-----------------+-------------------------+----------------------------------------------------------+
4 rows in set (0.02 sec)

mysql [test]>select array_map(x->cast(x as string), c_array1) from test_array_map_function;
+-----------------+-------------------------------------------------------+
| c_array1        | array_map([x] -> CAST(x(0) AS CHARACTER), `c_array1`) |
+-----------------+-------------------------------------------------------+
| [1, 2, 3, 4, 5] | ['1', '2', '3', '4', '5']                             |
| [6, 7, 8]       | ['6', '7', '8']                                       |
| []              | []                                                    |
| NULL            | NULL                                                  |
+-----------------+-------------------------------------------------------+
4 rows in set (0.01 sec)
```

### keywords

ARRAY,MAP,ARRAY_MAP