Performing queries on based on the output of a subquery - mysql

I am trying to perform a query based on the output of a sub-query. I would join the tables and perform one big query but that forces the query to search the entire table of one of the tables. The goal is to have the who (from table1), the what (from table2) and the when (from table3).
Here's what I have,
SELECT
DB1.TB1.`Date`,
DB1.TB1.`Sequence`,
DB1.TB1.`InstanceId`
FROM
(
SELECT
DB1.TB2.`UserName` AS USER,
DB1.TB2.`FirstName`,
DB1.TB2.`LastName`,
DB1.TB3.`ObjectName` AS OBJECT,
DB1.TB3.`ObjectType`
FROM
DB1.TB2
INNER JOIN DB1.TB3 ON DB1.TB2.`UserName` = DB1.TB3.`UserName`
INNER JOIN DB1.TB4 ON DB1.TB3.`ObjectName` = DB1.TB4.`ObjectName`
WHERE
DB1.TB4.`ADD` = 'Y' AND
DB1.TB2.`ADUC` NOT LIKE 'ServiceAccount' AND
DB1.TB3.`ObjectName` NOT IN ('ThisAdmin','ThatAdmin')
) AS MySubQuery
WHERE
DB1.TB1.`UserName` LIKE 'USER' AND
DB1.TB1.`ActionDetail` LIKE '%OBJECT%'
ORDER BY
DB1.TB1.`Date` DESC LIMIT 1

Related

MySQL INNER JOIN returning duplicate results

I have the following query:
SELECT t2.* ,t3.title ,t3.locale as locale FROM DocumentsTopics t1
INNER JOIN Documents t2 ON t1.di_name = t2.di_name
INNER JOIN DocumentsContent t3 ON t2.di_name = t3.di_name
WHERE locale='locale'
AND (t3.title LIKE '%searchphrase%' OR t3.summary LIKE '%searchphrase%') ORDER BY t2.uploadDate asc
LIMIT 0, 100
This query returns several of the records twice and even 3 times. I noticed that when I change the part in ()
from this below
(t3.title LIKE '%searchphrase%' OR t3.summary LIKE '%searchphrase%')
to the line below, I do not get multiple results.
(t3.title LIKE '%searchphrase%')
But I do need my query to check in more then one field.
Please help

Understaing the difference between two queries from performance point

I have this two version of the same query. Both produce same results (164 rows). But the second one takes .5 sec while the 1st one takes 17 sec. Can someone explain what's going on here?
TABLE organizations : 11988 ROWS
TABLE transaction_metas : 58232 ROWS
TABLE contracts_history : 219469 ROWS
# TAKES 17 SEC
SELECT contracts_history.buyer_id as id, org.name, SUM(transactions_count) as transactions_count, GROUP_CONCAT(DISTINCT(tm.value)) as balancing_authorities
From `contracts_history`
INNER JOIN `organizations` as `org`
ON `org`.`id` = `contracts_history`.`buyer_id`
LEFT JOIN `transaction_metas` as `tm`
ON `tm`.`contract_token` = `contracts_history`.`token` and `tm`.`field` = '1'
WHERE `contracts_history`.`seller_id` = '850'
GROUP BY `contracts_history`.`buyer_id` ORDER BY `balancing_authorities` DESC
# TAKES .6 SEC
SELECT contracts_history.buyer_id as id, org.name, SUM(transactions_count) as transactions_count, GROUP_CONCAT(DISTINCT(tm.value)) as balancing_authorities
From `contracts_history`
INNER JOIN `organizations` as `org`
ON `org`.`id` = `contracts_history`.`buyer_id`
left join (select * from `transaction_metas` where contract_token in (select token from `contracts_history` where seller_id = 850)) as `tm`
ON `tm`.`contract_token` = `contracts_history`.`token` and `tm`.`field` = '1'
WHERE `contracts_history`.`seller_id` = '850'
GROUP BY `contracts_history`.`buyer_id` ORDER BY `balancing_authorities` DESC
Explain Results:
First Query: https://prnt.sc/hjtiw6
Second Query: https://prnt.sc/hjtjjg
As based on my debugging of the first query it was clear that left join to transaction_metas table was making it slow, So I tried to limit its rows instead of joining to the full table. It seems to work but I don't understand why.
Join is a set of combinations from rows in your tables. That in mind, in the first query the engine combines all the results to filter just after. In second case one it applies the filter before it tries make the combinations.
The best case would make use of filter in JOIN clause without subquery.
Much like this:
SELECT contracts_history.buyer_id as id, org.name, SUM(transactions_count) as transactions_count, GROUP_CONCAT(DISTINCT(tm.value)) as balancing_authorities
From `contracts_history`
INNER JOIN `organizations` as `org`
ON `org`.`id` = `contracts_history`.`buyer_id`
AND `contracts_history`.`seller_id` = '850'
LEFT JOIN `transaction_metas` as `tm`
ON `tm`.`contract_token` = `contracts_history`.`token`
AND `tm`.`field` = 1
GROUP BY `contracts_history`.`buyer_id` ORDER BY `balancing_authorities` DESC
Note: When you reduce the size of the join tables by filtering with subqueries, it may allow the rows fit into the buffer. Nice trick to small buffer limit.
A Better explication:
https://dev.mysql.com/doc/refman/5.5/en/explain-output.html

Join another table in this sql query

I'm using this one to get related softwares based on their keywords. Now I want to add one more condition that is in another table called software_status having software_id. I found this query on SO, so I can't understand it and can't edit it further.
SELECT softwares.*, count(DISTINCT similar.kid) as shared_tags
FROM softwares
INNER JOIN ( keywords_softwares AS this_software INNER JOIN keywords_softwares AS similar USING (kid) ) ON similar.sid = softwares.id
WHERE this_software.sid=:id
AND softwares.id != this_software.sid
AND (softwares.subcategory = :subcatid or softwares.category = :catid)
GROUP BY softwares.id
ORDER BY shared_tags DESC LIMIT 10

Query for self join in MySQL

I have a query which gets the correct result but it is taking 5.5 sec to get the output.. Is there any other way to write a query for this -
SELECT metricName, metricValue
FROM Table sm
WHERE createdtime = (
SELECT MAX(createdtime)
FROM Table b
WHERE sm.metricName = b.metricName
AND b.sinkName='xx'
)
AND sm.sinkName='xx'
In your code, the subselect has to be run for every result row of the outer query, which should be quite expensive. Instead, you could select your filter data in a separate query and join both accordingly:
SELECT `metricName`, `metricValue` FROM Table sm
INNER JOIN (SELECT max(`createdtime`) AS `maxTime, `metricName` from Table b WHERE b.sinkName='xx' GROUP BY `metricName` ) filter
ON (sm.`createdtime` = filter.`maxTime`) AND ( sm.`metricName` = filter.`metricName`)
WHERE sm.sinkName='xx'

MySQL Inner Join with where clause sorting and limit, subquery?

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.