实例表:
postgres=# \d book Table "public.book" Column | Type | Modifiers --------+-------------------+--------------------------------------------------- id | integer | not null default nextval('book_id_seq'::regclass) name | character varying | tag | character varying |
postgres=# select * from book; id | name | tag ----+------+---------- 1 | java | aa,bb,cc 2 | C++ | dd,ee (2 rows)需要的效果:
name | unnest ------+-------- java | aa java | bb java | cc C++ | dd C++ | ee (5 rows)
postgres=# select name,unnest(string_to_array(tag,',')) from book; name | unnest ------+-------- java | aa java | bb java | cc C++ | dd C++ | ee (5 rows)
postgres=# select string_to_array(tag,') from book; string_to_array ----------------- {aa,cc} {dd,ee} (2 rows)方法2:regexp_split_to_table(字符串,分隔符)
postgres=# select name,regexp_split_to_table(tag,') from book; name | regexp_split_to_table ------+----------------------- java | aa java | bb java | cc C++ | dd C++ | ee (5 rows)
另外,字符串变数组的方法:
postgres=# select name,string_to_array(tag,') from book; name | string_to_array ------+----------------- java | {aa,cc} C++ | {dd,ee} (2 rows)
postgres=# select name,regexp_split_to_array(tag,') from book; name | regexp_split_to_array ------+----------------------- java | {aa,cc} C++ | {dd,ee} (2 rows)
原文地址:https://www.jb51.cc/postgresql/195308.html
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。