Postgres：正则表达式和嵌套查询，例如Unix管道 [英] Postgres: regex and nested queries something like Unix pipes

问题描述

命令应该执行：如果模式 *@he.com位于除标题之外的行上，则给出1作为输出：

  user_id |用户名|电邮| passhash_md5 |登录| has_been_sent_a_moderator_message | was_last_checked_by_moderator_at_time | a_moderator 
 --------- + ---------- + ----------- + ------------ ---------------------- + ----------- + --------------- -------------------- + ----------------------------- ---------- + ------------- 
 9 |他| [e-mail] | 6f96cfdfe5ccc627cadf24b41725caa4 | 0 | 1 | 2009-08-23 19：16：46.316272 |简而言之，我想用Regex连接许多SELECT命令，就像Unix管道一样。上面的输出来自SELECT命令。一条与模式匹配的新SELECT命令应该给我1。
 
 
 
 相关 
解决方案
您的意思是
 
 
  SELECT regexp_matches（（在用户名='masi'的情况下从用户中选择任意名称），'masi'）;  
 
 
您显然无法将记录（ * ）喂给 regexp_matches ，但是我认为这不是您的问题，因为您提到了在主题中嵌套SQL查询的问题。
 
 
 
也许您的意思是
 
 
  SELECT regexp_matches（wn，'masi'）FROM（SELECT whatname AS wn FROM users WHERE username LIKE'％masi％'）AS sq;  
 
 
子查询产生多个结果。
 
Command should do: Give 1 as output if the pattern "*@he.com" is on the row excluding the headings: 
 user_id | username |   email   |           passhash_md5           | logged_in | has_been_sent_a_moderator_message | was_last_checked_by_moderator_at_time | a_moderator 
---------+----------+-----------+----------------------------------+-----------+-----------------------------------+---------------------------------------+-------------
       9 | he       | [e-mail] | 6f96cfdfe5ccc627cadf24b41725caa4 |         0 |                                 1 | 2009-08-23 19:16:46.316272            | 
In short, I want to connect many SELECT-commands with Regex, rather like Unix pipes. The output above is from a SELECT-command. A new SELECT-command with matching the pattern should give me 1.

Related 
解决方案
Did you mean

  
SELECT regexp_matches( (SELECT whatevername FROM users WHERE username='masi'), 'masi');
you obviously can not feed the record (*) to regexp_matches, but I assume this is not what your problem is, since you mention the issue of nesting SQL queries in the subject.

Maybe you meant something like 

  
SELECT regexp_matches( wn, 'masi' ) FROM (SELECT whatevername AS wn FROM users WHERE username LIKE '%masi%') AS sq;
for the case when your subquery yields multiple results.

                        
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