开发的语言有数组的概念，对应于postgresql也有相关的数据字段类型，数组是英文array的翻译，可以定义一维，二维甚至更多维度，数学上跟矩阵很类似。在postgres里面可以直接存储使用，某些场景下使用很方便，也很强大。
PostgreSQL数组怎么添加元素
1、首先是插入数组数据，有两种方式
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# 方式1
postgres=# insert into t_kenyon(items) values('{1,2}');
INSERT 0 1
postgres=# insert into t_kenyon(items) values('{3,4,5}');
INSERT 0 1
# 方式2
postgres=# insert into t_kenyon(items) values(array[6,7,8,9]);
INSERT 0 1
postgres=# select * from t_kenyon;id | items
----+-----------
1 | {1,2}
2 | {3,4,5}
3 | {6,7,8,9}
(3 rows)2、数据删除
postgres=# delete from t_kenyon where id = 3; DELETe 1 postgres=# delete from t_kenyon where items[1] = 4; DELETe 0 postgres=# delete from t_kenyon where items[1] = 3; DELETe 1
3、数据更新（往数组内添加元素）
# 往后追加
postgres=# update t_kenyon set items = items||7;
UPDATE 1
postgres=# select * from t_kenyon;id | items
----+---------
1 | {1,2,7}
(1 row)
postgres=# update t_kenyon set items = items||'{99,66}';
UPDATE 1
postgres=# select * from t_kenyon;
id | items
----+------------------
1 | {1,2,7,55,99,66}
(1 row)
# 往前插
postgres=# update t_kenyon set items = array_prepend(55,items) ;
UPDATE 1
postgres=# select * from t_kenyon;
id | items
----+---------------------
1 | {55,1,2,7,55,99,66}
(1 row)
