I have the following two separate queries:
SELECT qry_tbl_G_ov_uni_atp.ID, Max(qry_tbl_G_ov_uni_atp.nElo_Ov) AS MaxOfnElo_Ov
FROM qry_tbl_G_ov_uni_atp
GROUP BY qry_tbl_G_ov_uni_atp.ID;
And:
SELECT qry_tbl_G_ov_uni_atp.ID, Max(qry_tbl_G_ov_uni_atp.nElo_Sur) AS MaxOfnElo_Sur1
FROM qry_tbl_G_ov_uni_atp
WHERE qry_tbl_G_ov_uni_atp.ID_C = 1
GROUP BY qry_tbl_G_ov_uni_atp.ID;
Both run fine and within a second or two. I want to combine them into one query so I have ID, MaxOfnElo_Ov and MaxOfnElo_Sur1 in the same output.
I know I need to use a sub query but my attempts take absolutely ages to display anything and then are barely useable as any attempt at scrolling locks Access up for an age again. I'm clearly not doing something right. Here's my sub query code:
SELECT qry_tbl_G_ov_uni_atp.ID, Max(qry_tbl_G_ov_uni_atp.nElo_Ov) AS MaxOfnElo_Ov, (SELECT Max(tt.nElo_Sur)
FROM qry_tbl_G_ov_uni_atp as tt
WHERE tt.ID_C = 1
AND tt.ID = qry_tbl_G_ov_uni_atp.ID) AS MaxOfnElo_Sur1
FROM qry_tbl_G_ov_uni_atp
GROUP BY qry_tbl_G_ov_uni_atp.ID;
You can use a subquery to achieve this as you have indicated. By using a sub-query in the JOIN as well you will get all results from a (your first query) and matching results from b (your second query):
SELECT a.ID,
a.MaxOfnElo_Ov,
b.MaxOfnElo_Sur1
FROM (
SELECT qry_tbl_G_ov_uni_atp.ID,
Max(qry_tbl_G_ov_uni_atp.nElo_Ov) AS MaxOfnElo_Ov
FROM qry_tbl_G_ov_uni_atp
GROUP BY qry_tbl_G_ov_uni_atp.ID
) a
LEFT JOIN (
SELECT qry_tbl_G_ov_uni_atp.ID,
Max(qry_tbl_G_ov_uni_atp.nElo_Sur) AS MaxOfnElo_Sur1
FROM qry_tbl_G_ov_uni_atp
WHERE qry_tbl_G_ov_uni_atp.ID_C = 1
GROUP BY qry_tbl_G_ov_uni_atp.ID
) b ON b.ID = a.ID
Note that this is untested, and assumes the ID is the same in both a and b (which I believe it is).
Related
I am trying to produce a result that shows duplicates in a table. One method I found for getting duplicates and showing them is to run the select statement again through an inner join. However, one of my columns needs to be the result of a function, and the only thing I can think to do is use an alias, however I can't use the alias twice in a SELECT statement.
I am not sure what the best way to run this code for getting the duplicates I need.
My code below
SELECT EXTRACT(YEAR_MONTH FROM date) as 'ndate', a.transponderID
FROM dispondo_prod_disposition.event a
inner JOIN (SELECT EXTRACT(YEAR_MONTH FROM date) as ???,
transponderID, COUNT(*)
FROM dispondo_prod_disposition.event
GROUP BY mdate, transponderID
HAVING count(*) > 1 ) b
ON ndate = ???
AND a.transponderID = b.transponderID
ORDER BY b.transponderID
SELECT b.ndate, transponderID
FROM dispondo_prod_disposition.event a
INNER JOIN ( SELECT EXTRACT(YEAR_MONTH FROM date) as ndate,
transponderID
FROM dispondo_prod_disposition.event
GROUP BY 1, 2
HAVING COUNT(*) > 1 ) b USING (transponderID)
WHERE b.ndate = ??? -- for example, WHERE b.ndate = 202201
ORDER BY transponderID
Server won't byte on this query, it takes too long to execute:
select prodavac.id, count(artikl.id) as brojartikala, count(poruceno.id) as brojporudzbina from prod_prodavac prodavac
inner join prod_artikl artikl
on prodavac.id=artikl.prodavacid
inner join prod_poruceno poruceno
on prodavac.id=poruceno.prodavacid
group by prodavac.id
On the other hand, both semi-queries run mega fast:
select prodavac.id, count(artikl.id) as brojartikala from prod_prodavac prodavac
inner join prod_artikl artikl
on prodavac.id=artikl.prodavacid
group by prodavac.id
Also the other one:
select prodavac.id, count(poruceno.id) as brojporudzbina from prod_prodavac prodavac
inner join prod_poruceno poruceno
on prodavac.id=poruceno.prodavacid
group by prodavac.id
order by prodavac.id asc
I would really like to do it in one query, so how to merge them correct way? All IDs are indexed integers.
Explain select shows this:
Depending on the relations between the tables and the data, your combined query might not even return the desired result. For a simple count of relations you can use correlated subqueries in the SELECT clause:
select prodavac.id, (
select count(*)
from prod_artikl artikl
where artikl.prodavacid = prodavac.id
) as brojartikala, (
select count(*)
from prod_poruceno poruceno
where poruceno.prodavacid = prodavac.id
) as brojporudzbina
from prod_prodavac prodavac
order by prodavac.id asc
While working with following query on mysql, Its getting locked,
SELECT event_list.*
FROM event_list
INNER JOIN members
ON members.profilenam=event_list.even_loc
WHERE (even_own IN (SELECT frd_id
FROM network
WHERE mem_id='911'
GROUP BY frd_id)
OR even_own = '911' )
AND event_list.even_active = 'y'
GROUP BY event_list.even_id
ORDER BY event_list.even_stat ASC
The Inner query inside IN constraint has many frd_id, So because of that above query is slooow..., So please help.
Thanks.
Try this:
SELECT el.*
FROM event_list el
INNER JOIN members m ON m.profilenam = el.even_loc
WHERE el.even_active = 'y' AND
(el.even_own = 911 OR EXISTS (SELECT 1 FROM network n WHERE n.mem_id=911 AND n.frd_id = el.even_own))
GROUP BY el.even_id
ORDER BY el.even_stat ASC
You don't need the GROUP BY on the inner query, that will be making the database engine do a lot of unneeded work.
If you put even_own = '911' before the select from network, then if even_own IS 911 then it will not have to do the subquery.
Also why do you have a group by on the subquery?
Also run explain plan top find out what is taking the time.
This might work better:
( SELECT e.*
FROM event_list AS e
INNER JOIN members AS m ON m.profilenam = e.even_loc
JOIN network AS n ON e.even_own = n.frd_id
WHERE n.mem_id = '911'
AND e.even_active = 'y'
ORDER BY e.even_stat ASC )
UNION DISTINCT
( SELECT e.*
FROM event_list AS e
INNER JOIN members AS m ON m.profilenam = e.even_loc
WHERE e.even_own = '911'
AND e.even_active = 'y' )
ORDER BY e.even_stat ASC
Since I don't know whether the JOINs one-to-many (or what), I threw in DISTINCT to avoid dups. There may be a better way, or it may be unnecessary (that is, UNION ALL).
Notice how I avoid two things that are performance killers:
OR -- turned into UNION
IN (SELECT...) -- turned into JOIN.
I made aliases to cut down on the clutter. I moved the ORDER BY outside the UNION (and added parens to make it work right).
I am trying to retrieve the max(date_entered) for a group of computer_ids.
The first query won't return accurate results. The second query gives me accurate results but essentially hangs unless I filter by a specific computer_id.
I'd rather use this first query
SELECT *, max(reports.date_entered)
FROM reports, hardware_reports
WHERE reports.report_id=hardware_reports.report_id
GROUP BY computer_id;
than this second query
SELECT *
FROM reports a
JOIN hardware_reports
ON a.report_id=hardware_reports.report_id
AND a.date_entered = (
SELECT MAX(date_entered)
FROM reports AS b
WHERE a.computer_id = b.computer_id)
and computer_id = 1648;
I need to either optimize second or get max to work in first.
You can alternative join it on a subquery that gets the latest record for every computer_ID.
SELECT a.*, c.*
FROM reports a
INNER JOIN
(
SELECT computer_ID, MAX(date_entered) date_entered
FROM reports
GROUP BY computer_ID
) b ON a.computer_ID = b.computer_ID
AND a.date_entered = b.date_entered
INNER JOIN hardware_reports c
ON a.report_id = c.report_id
To make it more efficient, provide an index on columns:
ALTER TABLE reports INDEX idx_report_compDate (computer_ID, date_entered)
Everything in the following query results in one line for each invBlueprintTypes row with the correct information. But I'm trying to add something to it. See below the codeblock.
Select
blueprintType.typeID,
blueprintType.typeName Blueprint,
productType.typeID,
productType.typeName Item,
productType.portionSize,
blueprintType.basePrice * 0.9 As bpoPrice,
productGroup.groupName ItemGroup,
productCategory.categoryName ItemCategory,
blueprints.productionTime,
blueprints.techLevel,
blueprints.researchProductivityTime,
blueprints.researchMaterialTime,
blueprints.researchCopyTime,
blueprints.researchTechTime,
blueprints.productivityModifier,
blueprints.materialModifier,
blueprints.wasteFactor,
blueprints.maxProductionLimit,
blueprints.blueprintTypeID
From
invBlueprintTypes As blueprints
Inner Join invTypes As blueprintType On blueprints.blueprintTypeID = blueprintType.typeID
Inner Join invTypes As productType On blueprints.productTypeID = productType.typeID
Inner Join invGroups As productGroup On productType.groupID = productGroup.groupID
Inner Join invCategories As productCategory On productGroup.categoryID = productCategory.categoryID
Where
blueprints.techLevel = 1 And
blueprintType.published = 1 And
productType.marketGroupID Is Not Null And
blueprintType.basePrice > 0
So what I need to get in here is the following table with the columns below it so I can use the values timestamp and sort the entire result by profitHour
tablename: invBlueprintTypesPrices
columns: blueprintTypeID, timestamp, profitHour
I need this information with the following select in mind. Using a select to show my intention of the JOIN/in-query select or whatever that can do this.
SELECT * FROM invBlueprintTypesPrices
WHERE blueprintTypeID = blueprintType.typeID
ORDER BY timestamp DESC LIMIT 1
And I need the main row from table invBlueprintTypes to still show even if there is no result from the invBlueprintTypesPrices. The LIMIT 1 is because I want the newest row possible, but deleting the older data is not a option since history is needed.
If I've understood correctly I think I need a subquery select, but how to do that? I've tired adding the exact query that is above with a AS blueprintPrices after the query's closing ), but did not work with a error with the
WHERE blueprintTypeID = blueprintType.typeID
part being the focus of the error. I have no idea why. Anyone who can solve this?
You'll need to use a LEFT JOIN to check for NULL values in invBlueprintTypesPrices. To mimic the LIMIT 1 per TypeId, you can use the MAX() or to truly make sure you only return a single record, use a row number -- this depends on whether you can have multiple max time stamps for each type id. Assuming not, then this should be close:
Select
...
From
invBlueprintTypes As blueprints
Inner Join invTypes As blueprintType On blueprints.blueprintTypeID = blueprintType.typeID
Inner Join invTypes As productType On blueprints.productTypeID = productType.typeID
Inner Join invGroups As productGroup On productType.groupID = productGroup.groupID
Inner Join invCategories As productCategory On productGroup.categoryID = productCategory.categoryID
Left Join (
SELECT MAX(TimeStamp) MaxTime, TypeId
FROM invBlueprintTypesPrices
GROUP BY TypeId
) blueprintTypePrice On blueprints.blueprintTypeID = blueprintTypePrice.typeID
Left Join invBlueprintTypesPrices blueprintTypePrices On
blueprintTypePrice.TypeId = blueprintTypePrices.TypeId AND
blueprintTypePrice.MaxTime = blueprintTypePrices.TimeStamp
Where
blueprints.techLevel = 1 And
blueprintType.published = 1 And
productType.marketGroupID Is Not Null And
blueprintType.basePrice > 0
Order By
blueprintTypePrices.profitHour
Assuming you might have the same max time stamp with 2 different records, replace the 2 left joins above with something similar to this getting the row number:
Left Join (
SELECT #rn:=IF(#prevTypeId=TypeId,#rn+1,1) rn,
TimeStamp,
TypeId,
profitHour,
#prevTypeId:=TypeId
FROM (SELECT *
FROM invBlueprintTypesPrices
ORDER BY TypeId, TimeStamp DESC) t
JOIN (SELECT #rn:=0) t2
) blueprintTypePrices On blueprints.blueprintTypeID = blueprintTypePrices.typeID AND blueprintTypePrices.rn=1
You don't say where you are putting the subquery. If in the select clause, then you have a problem because you are returning more than one value.
You can't put this into the from clause directly, because you have a correlated subquery (not allowed).
Instead, you can put it in like this:
from . . .
(select *
from invBLueprintTypesPrices ibptp
where ibtp.timestamp = (select ibptp2.timestamp
from invBLueprintTypesPrices ibptp2
where ibptp.blueprintTypeId = ibptp2.blueprintTypeId
order by timestamp desc
limit 1
)
) ibptp
on ibptp.blueprintTypeId = blueprintType.TypeID
This identifies the most recent records for all the blueprintTypeids in the subquery. It then joins in the one that matches.