Display mysql results in one row - mysql

Question

mysql> select * from facts;
+----+---------+------------+---------+
| id | fact_id | fact_value | host_id |
+----+---------+------------+---------+
| 1 | 1 | rh5 | 1 |
| 2 | 1 | rh4 | 2 |
| 3 | 2 | virtual | 1 |
| 4 | 2 | virtual | 2 |
| 5 | 3 | rack 2 | 1 |
+----+---------+------------+---------+
mysql> select * from hosts;
+---------+-----------+
| host_id | host_name |
+---------+-----------+
| 1 | bellagio |
| 2 | mirage |
+---------+-----------+
The query I used does the following:
mysql> select host_name,fact_value from hosts as a left join facts as b on
> b.host_id=a.host_id and b.fact_id in (1,2,3);
+-----------+------------+
| host_name | fact_value |
+-----------+------------+
| bellagio | rh5 |
| bellagio | virtual |
| bellagio | rack 2 |
| mirage | rh4 |
| mirage | virtual |
+-----------+------------+
I want the results to print one row for each host, notice how it prints each fact_value on a separate row. The reason why i have the IN clause is that this table has over 40 possible columns for each host. I only want a handful (I select 3 in this example).
Here's what i'm looking for.
+-----------+--------+-----------+-----------+
| host_name | value1 | value 2 | value 3 |
+-----------+--------+-----------+-----------+
| bellagio | rh5 | virtual | rack 2 |
| mirage | rh4 | virtual | NULL |
+-----------+--------+-----------+-----------+

Answer 1

SELECT GROUP_CONCAT(fact_value)...
...
GROUP BY host_name

Answer 2

You could try creating a view on each of the value columns and then joining the columns.
create view [first_values] as
select fact_value, host_id
from facts where fact_id = 1;
create view [second_values] as
select fact_value, host_id
from facts where fact_id = 2;
create view [third_values] as
select fact_value, host_id
from facts where fact_id = 3;
now join the columns:
select h.host_name, f.fact_value as value1, s.fact_value as value2, t.fact_value as value3
from hosts as h
left join [first_values] as f on h.host_id = f.host_id
left join [second_values] as s on h.host_id = s.host_id
left join [third_values] as t on h.host_id = t.host_id;

Answer 3

This works ... granted some of the field names have changed since I last posted.
select distinct t0.host_id, t1.name, t2.value as os_type, t3.value as ip_addr, t4.value as rack, t5.value as host_owner, t6.value as host_memory,
t7.value as host_swap, t8.value as host_make, t9.value as host_model
FROM fact_values t0 left outer join hosts t1 on (t0.host_id=t1.id)
left outer join fact_values t2 on (t0.host_id=t2.host_id and t2.fact_name_id = 30)
left outer join fact_values t3 on (t0.host_id = t3.host_id and t3.fact_name_id = 13)
left outer join fact_values t4 on (t0.host_id = t4.host_id and t4.fact_name_id = 65)
left outer join fact_values t5 on (t0.host_id = t5.host_id and t5.fact_name_id = 81)
left outer join fact_values t6 on (t0.host_id = t6.host_id and t6.fact_name_id = 18)
left outer join fact_values t7 on (t0.host_id = t7.host_id and t7.fact_name_id = 51)
left outer join fact_values t8 on (t0.host_id = t8.host_id and t8.fact_name_id = 36)
left outer join fact_values t9 on (t0.host_id = t9.host_id and t9.fact_name_id = 47)
WHERE t1.name = '$hostname'

Answer 4

SELECT u.user_id,u2.acc_no AS pacc,u3.acc_no AS sacc
FROM table_name AS u
LEFT JOIN table_name AS u2 ON u2.user_id=u.user_id AND u2.acc_type='P' AND u2.lab_id = ? AND u2.category = 'SOMETHING'
LEFT JOIN table_name AS u3 ON u3.user_id=u.user_id AND u3.acc_type='S' AND u3.lab_id = ? AND u3.category = 'SOMETHING'
GROUP BY u.user_id
I have used the abouve query to get multiple rows to single row from the same table . Which is worked fine with me ..