RE:Re: A complex SQL query

Yes, that's exactly what works for me.

Thanks a bunch!!!

--From: janis(at)puris(dot)lv
--To: pgsql-sql(at)lists(dot)postgresql(dot)org,jj08(at)drivehq(dot)com
--Date: 9/6/2019 5:56:10 AM --Subject: Re: A complex SQL query Would something like this work for you ? http://www.sqlfiddle.com/#!17/2e45eb/9 select user_id, max(start_date) as start_date, case when max(end_date) < max(start_date) then null else max(end_date) end as end_date</div> from employment where employer = 'Micro' group by user_id ; On 6 Sep 2019, 14:31 +0200, jj08 <jj08(at)drivehq(dot)com>
, wrote:

I hope someone can give me some pointers.

Here is my table.

+--------+----------+------------+-----------+

| usr_id | employer | start_date | end_date |

+--------+----------+------------+-----------+

| A | Goo | 201904 | - |

| A | Micro | 201704 | 201903 |

| B | Micro | 201706 | - |

| B | Goo | 201012 | 201705 |

| B | Micro | 201001 | 201011 |

+--------+----------+------------+-----------+

I am trying to list up people working for a company called &quot;Micro&quot;.

Some people work for a company multiple times, like user B.

I only need one line per user, displaying only the latest affiliation date.

For user_id &quot;B&quot;, I could do Select user_id, MAX(start_date), end_date where employer = 'Micro',

but that would fail to get record for user_id &quot;A&quot;.

If multiple records exist, I want to do MAX, but if only a single record exists, I don't need MAX.

How do I do that?

From the above data, I would like to see only two lines:

| A | Micro | 201704 | 201903 |

| B | Micro | 201706 | - |

Thank you.

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