Question

I have this query…

    $sQuery = "
        SELECT SQL_CALC_FOUND_ROWS ".str_replace(" , ", " ", implode(", ", $aColumns))."
        FROM   dominios left join datas on dominios.id_dominio=datas.id_dominio
left join dnss on dominios.id_dominio=dnss.id_dominio
left join entidades_gestoras on dominios.id_dominio=entidades_gestoras.id_dominio
left join estados on dominios.id_dominio=estados.id_dominio
left join ips on dominios.id_dominio=ips.id_dominio
left join quantidade_dnss on dominios.id_dominio=quantidade_dnss.id_dominio
left join responsaveis_tecnicos on dominios.id_dominio=responsaveis_tecnicos.id_dominio
left join titulares on dominios.id_dominio=titulares.id_dominio 
        WHERE dominios.estado not like 2 and dominios.estado not like 0 AND data_expiracao > '".date("Ymd")."' $sWhere $where 
        GROUP BY dominio 
        $sOrder
        $sLimit
        ";

It returns me the results I ‘need’…
But the Group By, it show me the first result that appear on the database, and I needed the last…

How can I do this? :s

Edited
This is the final query, without those variables

  SELECT SQL_CALC_FOUND_ROWS `datas`.`data_insercao`, `datas`.`data_expiracao`, `datas`.`data_registo`, 
`dominios`.`dominio`, 
`titulares`.`nome`, `titulares`.`morada`, `titulares`.`email`, `titulares`.`localidade`, `titulares`.`cod_postal`, 
`entidades_gestoras`.`nome`, `entidades_gestoras`.`email`, 
`responsaveis_tecnicos`.`nome`, `responsaveis_tecnicos`.`email`, 
`ips`.`ip`, `dominios`.`id_dominio` FROM dominios left join datas on dominios.id_dominio=datas.id_dominio 
left join dnss on dominios.id_dominio=dnss.id_dominio 
left join entidades_gestoras on dominios.id_dominio=entidades_gestoras.id_dominio 
left join estados on dominios.id_dominio=estados.id_dominio 
left join ips on dominios.id_dominio=ips.id_dominio 
left join quantidade_dnss on dominios.id_dominio=quantidade_dnss.id_dominio 
left join responsaveis_tecnicos on dominios.id_dominio=responsaveis_tecnicos.id_dominio left join titulares on dominios.id_dominio=titulares.id_dominio WHERE dominios.estado not like 2 and dominios.estado not like 0 AND data_expiracao > '20120730' GROUP BY dominio ORDER BY `datas`.`data_insercao` asc LIMIT 0, 10

Answer 1

General considerations

I’m not sure what columsn you have in aColumns, or what table that dominio column comes from. When you group a number of rows using GROUP BY, then the columns you select for your result should either have the same value for all rows of the group (i.e. be functionally dependent), or should be some aggregate function combining the values of all the rows in the group.

Some SQL dialects enforce this. MySQL doesn’t, but if you select an unaggregated column which has different values within the group, there are no guarantees as to what value will actually be returned to you. It might come from any row within the group. So there is no way to get the “last” of these rows, as there isn’t any inherent order. In simple cases you can use MIN or MAX to select the value you need. In more complicated cases, you’ll most likely have to use subqueries to do the selection from within the groups.

For example, this answer computes for every Name (which corresponds to your dominio grouping column) the last value of Action based on an ordering by ascending Time. Or rather the first value using a descending ordering, which is the same.

Your application

As your comment below indicates that you want the maximal id_dominio for each dominio in dominios, I suggest the following:

SELECT …
FROM (SELECT MAX(id_dominio) AS id_dominio
      FROM dominios
      GROUP BY dominio
      WHERE estado <> 2
        AND estado <> 0
     ) domIds
LEFT JOIN datas ON domIds.id_dominio=datas.id_dominio
…

So there will be one subquery to compute the maximal id_dominio for each dominio group, and all subsequent joins can use the IDs from that subquery instead of the full dominio table. If you need other columns from the dominio table as well, you might have to include that in the join again, so that you can get all the values from those row3s whose IDs you selected in the subquery.