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SinceVersion dev
array_map(lambda,array1,array2….)
description
Syntax
ARRAY<T> array_map(lambda, ARRAY<T> array1, ARRAY<T> array2)
使用一个lambda表达式作为输入参数，对其他的输入ARRAY参数的内部数据做对应表达式计算。 在lambda表达式中输入的参数为1个或多个，必须和后面的输入array列数量一致。 在lambda中可以执行合法的标量函数，不支持聚合函数等。
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
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
