table 1
|id | name |
|1 | Test |
|2 | Hello|
|3 | Hii |
table 2
|id | related_id | date | time
|1 | 1 | 2014-09-11 | 12.56.25
|2 | 2 | 2014-09-11 | 12.56.25
|3 | 2 | 2014-09-12 | 11.56.25
|4 | 2 | 2014-09-12 | 12.56.31 (Last record)
OUTPUT
|id | name | date | time
|1 | test | 2014-09-11 | 12.56.25
|2 | Hello | 2014-09-12 | 12.56.31 (This is the last record from table 2)
|3 | Hii | - | -
SO in output table, Id=2 is last record of table 2 where relative id=2 ... and I also want all records from table 1.
So Which kind of Join Query I can use?
You can do so by using self join for table2 to get the last row for each related_id
group and use left join with inner select with your table1
select a.*,
d.`date`,
d.`time`
from table1 a
left join (
select b.*
from table2 b
inner join (
select
max(id) id ,
related_id
from table2
group by related_id ) c
on(b.id=c.id and b.related_id = c.related_id)
) d
on(a.id = d.related_id)
Another way would be use substring_index
and group_concat
with order by
select a.*,
substring_index(group_concat(b.`date` order by b.id desc),',',1) `date`,
substring_index(group_concat(b.`time` order by b.id desc),',',1) `time`
from table1 a
left join table2 b
on(a.id = b.related_id)
group by a.id
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