I have a table:
custID orderID orderComponent
=====================================
1 123 pizza
1 123 wings
1 234 breadsticks
1 239 salad
2 456 pizza
2 890 salad
I have a list of values - pizza, wings, breadsticks, and salad. I need a way to just get a true/false value if a customer has at least one record containing each of these. Is that possible with a mysql query, or do I just have to do a select distinct(orderComponent)
for each user and use php to check the results?
If you are just looking to see if the customer has ordered all items, then you can use:
select t1.custid,
case when t2.total is not null
then 'true'
else 'false'
end OrderedAll
from yourtable t1
left join
(
select custid, count(distinct orderComponent) Total
from yourtable
where orderComponent in ('pizza', 'wings', 'breadsticks', 'salad')
group by custid
having count(distinct orderComponent) = 4
) t2
on t1.custid = t2.custid
If you want to expand this out, to see if the custid
has ordered all items in a single order, then you can use:
select t1.custid,
t1.orderid,
case when t2.total is not null
then 'true'
else 'false'
end OrderedAll
from yourtable t1
left join
(
select custid, orderid, count(distinct orderComponent) Total
from yourtable
where orderComponent in ('pizza', 'wings', 'breadsticks', 'salad')
group by custid, orderID
having count(distinct orderComponent) = 4
) t2
on t1.custid = t2.custid
and t1.orderId = t2.orderid
If you only want the custid and the true/false value, then you can add distinct
to the query.
select distinct t1.custid,
case when t2.total is not null
then 'true'
else 'false'
end OrderedAll
from yourtable t1
left join
(
select custid, count(distinct orderComponent) Total
from yourtable
where orderComponent in ('pizza', 'wings', 'breadsticks', 'salad')
group by custid
having count(distinct orderComponent) = 4
) t2
on t1.custid = t2.custid
Or by custid and orderid:
select distinct
t1.custid,
t1.orderid,
case when t2.total is not null
then 'true'
else 'false'
end OrderedAll
from yourtable t1
left join
(
select custid, orderid, count(distinct orderComponent) Total
from yourtable
where orderComponent in ('pizza', 'wings', 'breadsticks', 'salad')
group by custid, orderID
having count(distinct orderComponent) = 4
) t2
on t1.custid = t2.custid
and t1.orderId = t2.orderid
select case when
count(distinct orderComponent) = 4
then 'true'
else 'false'
end as bool
from tbl
where custID=1
Here's one approach. This approach does not require an inline view (derived table), and can be effective if you want to include flags for multiple conditions:
This returns custID
that has a row for all four items:
SELECT t.custID
, MAX(IF(t.orderComponent='breadsticks',1,0))
+ MAX(IF(t.orderComponent='pizza',1,0))
+ MAX(IF(t.orderComponent='salad',1,0))
+ MAX(IF(t.orderComponent='wings',1,0)) AS has_all_four
FROM mytable t
GROUP BY t.custID
HAVING has_all_four = 4
(This checked for a customer "order" that had all four items, rather than just a "custID".)
SELECT t.custID
, t.orderID
, MAX(IF(t.orderComponent='breadsticks',1,0))
+ MAX(IF(t.orderComponent='pizza',1,0))
+ MAX(IF(t.orderComponent='salad',1,0))
+ MAX(IF(t.orderComponent='wings',1,0)) AS has_all_four
-- , MAX(IF(t.orderComponent='breadsticks',1,0)) AS has_breadsticks
-- , MAX(IF(t.orderComponent='pizza',1,0)) AS has_pizza
-- , MAX(IF(t.orderComponent='salad',1,0)) AS has_salad
-- , MAX(IF(t.orderComponent='wings',1,0)) AS has_wings
FROM mytable t
GROUP BY t.custID, t.orderID
HAVING has_all_four = 4
That will get the "orders" that have all four items. If you want to return just values for custID, then use the query above as an inline view (wrap it in another query)
SELECT s.custID
FROM (
SELECT t.custID
, t.orderID
, MAX(IF(t.orderComponent='breadsticks',1,0))
+ MAX(IF(t.orderComponent='pizza',1,0))
+ MAX(IF(t.orderComponent='salad',1,0))
+ MAX(IF(t.orderComponent='wings',1,0)) AS has_all_four
FROM mytable t
GROUP BY t.custID, t.orderID
HAVING has_all_four = 4
) s
GROUP BY s.custID
@EmmyS: you can do it both ways. If you want to check using MySql use:
SELECT @rowcount:=COUNT(*) FROM orderComponent Where (Your Conditions);
IF (@rowcount > 0) THEN
'True'
ELSE
'False'
END IF
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