Union and order by together

0

Well I have in the MYSQL database the chatlogs table with: from, to, msg, datetime.

Where are the messages exchanged and information ok, starting from this point I would like to know how to do a history of the messages, for example:

  

user carlos logged into his account in maria's chat so he would retrieve the old conversations again in order by datahr using datetime

Ex:

select msg from chatlogs where de = joana and para = carlos order by datetime ... conseguiria recuperar o historico msgs dela em ordem ... porem preciso que o histórico mostre tudo em ordem minhas msg tambem ... 

Ex:

  

joana: hi   Hi, how are you?   joana: Yes, and you?   carlos: td ok

of correct order + I do not know how I would have done it,

select msg from chatlogs where de = joana and para = carlos 
union
select msg from chatlogs where de = carlos and para = joana 
order by datetime

Explanation of what I tried to do: I tried to get all msg sent from carlos to joana and all msg from joana to carlos and joined with union everything and then I had to receive in order by datehr.

Any suggestions?

    
asked by anonymous 11.03.2015 / 20:37

1 answer

2

You can have this result simply by changing your select without the need to use union .

select msg from chatlogs where (de = joana and para = carlos) or (de = carlos and para = joana) order by datetime
    
11.03.2015 / 20:49