array_map

SinceVersion dev

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.

  1. array_map(x->x, array1);
  2. array_map(x->(x+2), array1);
  3. array_map(x->(abs(x)-2), array1);
  5. array_map((x,y)->(x = y), array1, array2);
  6. array_map((x,y)->(power(x,2)+y), array1, array2);
  7. array_map((x,y,z)->(abs(x)+y*z), array1, array2, array3);

example

  2. mysql [test]>select *, array_map(x->x,[1,2,3]) from array_test2 order by id;
  3. +------+-----------------+-------------------------+----------------------------------------+
  4. | id   | c_array1        | c_array2                | array_map([x] -> x(0), ARRAY(1, 2, 3)) |
  5. +------+-----------------+-------------------------+----------------------------------------+
  6. |    1 | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [1, 2, 3]                              |
  7. |    2 | [6, 7, 8]       | [10, 12, 13]            | [1, 2, 3]                              |
  8. |    3 | [1]             | [-100]                  | [1, 2, 3]                              |
  9. |    4 | NULL            | NULL                    | [1, 2, 3]                              |
  10. +------+-----------------+-------------------------+----------------------------------------+
  11. 4 rows in set (0.02 sec)
  13. mysql [test]>select *, array_map(x->x+2,[1,2,3]) from array_test2 order by id;
  14. +------+-----------------+-------------------------+--------------------------------------------+
  15. | id   | c_array1        | c_array2                | array_map([x] -> x(0) + 2, ARRAY(1, 2, 3)) |
  16. +------+-----------------+-------------------------+--------------------------------------------+
  17. |    1 | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [3, 4, 5]                                  |
  18. |    2 | [6, 7, 8]       | [10, 12, 13]            | [3, 4, 5]                                  |
  19. |    3 | [1]             | [-100]                  | [3, 4, 5]                                  |
  20. |    4 | NULL            | NULL                    | [3, 4, 5]                                  |
  21. +------+-----------------+-------------------------+--------------------------------------------+
  22. 4 rows in set (0.02 sec)
  24. mysql [test]>select c_array1, c_array2, array_map(x->x,[1,2,3]) from array_test2 order by id;
  25. +-----------------+-------------------------+----------------------------------------+
  26. | c_array1        | c_array2                | array_map([x] -> x(0), ARRAY(1, 2, 3)) |
  27. +-----------------+-------------------------+----------------------------------------+
  28. | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [1, 2, 3]                              |
  29. | [6, 7, 8]       | [10, 12, 13]            | [1, 2, 3]                              |
  30. | [1]             | [-100]                  | [1, 2, 3]                              |
  31. | NULL            | NULL                    | [1, 2, 3]                              |
  32. +-----------------+-------------------------+----------------------------------------+
  33. 4 rows in set (0.01 sec)
  35. mysql [test]>select c_array1, c_array2, array_map(x->power(x,2),[1,2,3]) from array_test2 order by id;
  36. +-----------------+-------------------------+----------------------------------------------------+
  37. | c_array1        | c_array2                | array_map([x] -> power(x(0), 2.0), ARRAY(1, 2, 3)) |
  38. +-----------------+-------------------------+----------------------------------------------------+
  39. | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [1, 4, 9]                                          |
  40. | [6, 7, 8]       | [10, 12, 13]            | [1, 4, 9]                                          |
  41. | [1]             | [-100]                  | [1, 4, 9]                                          |
  42. | NULL            | NULL                    | [1, 4, 9]                                          |
  43. +-----------------+-------------------------+----------------------------------------------------+
  45. mysql [test]>select c_array1, c_array2, array_map((x,y)->x+y,c_array1,c_array2) from array_test2 order by id;
  46. +-----------------+-------------------------+----------------------------------------------------------+
  47. | c_array1        | c_array2                | array_map([x, y] -> x(0) + y(1), `c_array1`, `c_array2`) |
  48. +-----------------+-------------------------+----------------------------------------------------------+
  49. | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [11, 22, -37, 84, -95]                                   |
  50. | [6, 7, 8]       | [10, 12, 13]            | [16, 19, 21]                                             |
  51. | [1]             | [-100]                  | [-99]                                                    |
  52. | NULL            | NULL                    | NULL                                                     |
  53. +-----------------+-------------------------+----------------------------------------------------------+
  54. 4 rows in set (0.02 sec)
  56. 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;
  57. +-----------------+-------------------------+----------------------------------------------------------------------+
  58. | c_array1        | c_array2                | array_map([x, y] -> power(x(0), 2.0) + y(1), `c_array1`, `c_array2`) |
  59. +-----------------+-------------------------+----------------------------------------------------------------------+
  60. | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [11, 24, -31, 96, -75]                                               |
  61. | [6, 7, 8]       | [10, 12, 13]            | [46, 61, 77]                                                         |
  62. | [1]             | [-100]                  | [-99]                                                                |
  63. | NULL            | NULL                    | NULL                                                                 |
  64. +-----------------+-------------------------+----------------------------------------------------------------------+
  65. 4 rows in set (0.03 sec)
  67. mysql [test]>select *,array_map(x->x=3,c_array1) from array_test2 order by id;
  68. +------+-----------------+-------------------------+----------------------------------------+
  69. | id   | c_array1        | c_array2                | array_map([x] -> x(0) = 3, `c_array1`) |
  70. +------+-----------------+-------------------------+----------------------------------------+
  71. |    1 | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [0, 0, 1, 0, 0]                        |
  72. |    2 | [6, 7, 8]       | [10, 12, 13]            | [0, 0, 0]                              |
  73. |    3 | [1]             | [-100]                  | [0]                                    |
  74. |    4 | NULL            | NULL                    | NULL                                   |
  75. +------+-----------------+-------------------------+----------------------------------------+
  76. 4 rows in set (0.02 sec)
  78. mysql [test]>select *,array_map(x->x>3,c_array1) from array_test2 order by id;
  79. +------+-----------------+-------------------------+----------------------------------------+
  80. | id   | c_array1        | c_array2                | array_map([x] -> x(0) > 3, `c_array1`) |
  81. +------+-----------------+-------------------------+----------------------------------------+
  82. |    1 | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [0, 0, 0, 1, 1]                        |
  83. |    2 | [6, 7, 8]       | [10, 12, 13]            | [1, 1, 1]                              |
  84. |    3 | [1]             | [-100]                  | [0]                                    |
  85. |    4 | NULL            | NULL                    | NULL                                   |
  86. +------+-----------------+-------------------------+----------------------------------------+
  87. 4 rows in set (0.02 sec)
  89. mysql [test]>select *,array_map((x,y)->x>y,c_array1,c_array2) from array_test2 order by id;
  90. +------+-----------------+-------------------------+----------------------------------------------------------+
  91. | id   | c_array1        | c_array2                | array_map([x, y] -> x(0) > y(1), `c_array1`, `c_array2`) |
  92. +------+-----------------+-------------------------+----------------------------------------------------------+
  93. |    1 | [1, 2, 3, 4, 5] | [10, 20, -40, 80, -100] | [0, 0, 1, 0, 1]                                          |
  94. |    2 | [6, 7, 8]       | [10, 12, 13]            | [0, 0, 0]                                                |
  95. |    3 | [1]             | [-100]                  | [1]                                                      |
  96. |    4 | NULL            | NULL                    | NULL                                                     |
  97. +------+-----------------+-------------------------+----------------------------------------------------------+
  98. 4 rows in set (0.02 sec)
  100. mysql [test]>select array_map(x->cast(x as string), c_array1) from test_array_map_function;
  101. +-----------------+-------------------------------------------------------+
  102. | c_array1        | array_map([x] -> CAST(x(0) AS CHARACTER), `c_array1`) |
  103. +-----------------+-------------------------------------------------------+
  104. | [1, 2, 3, 4, 5] | ['1', '2', '3', '4', '5']                             |
  105. | [6, 7, 8]       | ['6', '7', '8']                                       |
  106. | []              | []                                                    |
  107. | NULL            | NULL                                                  |
  108. +-----------------+-------------------------------------------------------+
  109. 4 rows in set (0.01 sec)

keywords

ARRAY,MAP,ARRAY_MAP