【AntDB数据库 SQL语法专栏】——常用函数（12）

示例

antdb=# select array_append(ARRAY[1,2], 3);
 array_append
--------------
 {1,2,3}
(1 row)

antdb=# select array_cat(ARRAY[1,2,3], ARRAY[4,5]);
  array_cat
-------------
 {1,2,3,4,5}
(1 row)

antdb=# select array_ndims(ARRAY[[1,2,3], [4,5,6]]);
 array_ndims
-------------
           2
(1 row)

antdb=# select array_dims(ARRAY[[1,2,3], [4,5,6]]);
 array_dims
------------
 [1:2][1:3]
(1 row)

antdb=# select array_fill(7, ARRAY[3], ARRAY[2]);
  array_fill
---------------
 [2:4]={7,7,7}
(1 row)

antdb=# select array_length(array[1,2,3], 1);
 array_length
--------------
            3
(1 row)

antdb=# select array_lower('[0:2]={1,2,3}'::int[], 1);
 array_lower
-------------
           0
(1 row)

antdb=# select array_position(ARRAY['sun','mon','tue','wed','thu','fri','sat'], 'mon');
 array_position
----------------
              2
(1 row)

antdb=# select array_positions(ARRAY['A','A','B','A'], 'A');
 array_positions
-----------------
 {1,2,4}
(1 row)

antdb=# select array_prepend(1, ARRAY[2,3]);
 array_prepend
---------------
 {1,2,3}
(1 row)

antdb=# select array_remove(ARRAY[1,2,3,2], 2);
 array_remove
--------------
 {1,3}
(1 row)

antdb=# select array_replace(ARRAY[1,2,5,4], 5, 3);
 array_replace
---------------
 {1,2,3,4}
(1 row)

antdb=# select array_to_string(ARRAY[1, 2, 3, NULL, 5], ',', '*');
 array_to_string
-----------------
 1,2,3,*,5
(1 row)

antdb=# select array_upper(ARRAY[1,8,3,7], 1);
 array_upper
-------------
           4
(1 row)

antdb=# select cardinality(ARRAY[[1,2],[3,4]]);
 cardinality
-------------
           4
(1 row)

antdb=# select string_to_array('xx~^~yy~^~zz', '~^~', 'yy');
 string_to_array
-----------------
 {xx,NULL,zz}
(1 row)

antdb=# select unnest(ARRAY[1,2]);
 unnest
--------
      1
      2
(2 rows)