I have an input parameter to a query I'm trying to write. Basically, if mostRecentSnapshot == true then I want to select only the most recent records from the process run (basically where max(creationDate)) and if mostRecentSnapshot == false then select creationDate and other columns normally.
To me, it makes sense to do this if statement in the from clause, but I don't think that's possible. Normally I would use a CTE, but I those don't exist in MySQL.
What is the best way to achieve this?
It would be something along the lines of this:
SELECT
CASE mostRecentSnapshot WHEN FALSE THEN
(
processauditheader.creationDate as processCreationDate,
processauditheader.processName,
processauditheader.processType,
processauditheader.processHost,
processauditheader.processDatabase,
processauditheader.tableAudited,
processauditheader.processInvokedByName,
processauditheader.processInvokedByType,
processauditheader.processInvokedByDatabase,
processauditheader.processIntervalValue,
processauditheader.processIntervalField,
processauditheader.auditScenarios,
processaudititerationdetail.creationDate as iterationDate,
processaudititerationdetail.connectionId,
processaudititerationdetail.processDate,
processaudititerationdetail.tableRowCount,
processaudititerationdetail.tableRowCountLastDay,
processaudititerationdetail.previousProcessAuditIterationDetailID,
processauditmetricdetail.creationDate,
processauditmetricdetail.processAuditIterationDetailID,
processauditmetricdetail.auditMetric,
processauditmetricdetail.auditTotal,
processauditmetricdetail.auditExample
)
WHEN TRUE THEN
(
((SELECT MAX(processaudititerationdetail.creationDate) as maxSnapshot,
processaudititerationdetail.id
from reporting_audit.processaudititerationdetail
group by processaudititerationdetail.creationDate) mostRecent
JOIN reporting_audit.processaudititerationdetail ON mostRecent.id = processaudititerationdetail.id)
)
END
FROM reporting_audit.processauditheader
JOIN processaudititerationdetail ON processaudititerationdetail.processAuditHeaderID = processauditheader.id
LEFT JOIN processauditmetricdetail ON processauditmetricdetail.processAuditIterationDetailID = processaudititerationdetail.id
A query can only return a fixed set of columns. Perhaps the following does what you want:
select paid.*
from reporting_audit.processaudititerationdetail paid
where (not v_mostRecentSnapshot) or
paid.creation_date = (select max(paid2.creationDate from reporting_audit.processaudititerationdetail paid2);
It will either select all records from the table or only the record(s) that have the most recent creationDate.
Related
I want to optimize these SQL queries using if-else but how I should use it? .
if this query result contain 'ALL'
SELECT
bdsubcategory.subcategoryID as ID,
bdsubcategory.subcategoryName as Name
FROM
phonebook.newsms_subscription
INNER JOIN bdsubcategory ON bdsubcategory.subcategoryID = newsms_subscription.subcategoryID
INNER JOIN newsms_client ON newsms_subscription.clientID =newsms_client.clientID
INNER JOIN newsms_person ON newsms_subscription.personID = newsms_person.personID
WHERE
newsms_subscription.isActive = 1 AND
newsms_person.personID = '856'
Then i want to query this
SELECT
bdsubcategory.subcategoryID as ID,
bdsubcategory.subcategoryName as Name
FROM
phonebook.newsms_subscription
INNER JOIN bdsubcategory ON bdsubcategory.subcategoryID = newsms_subscription.subcategoryID
INNER JOIN newsms_person ON newsms_subscription.personID = newsms_person.personID
WHERE
newsms_subscription.isActive = 1
GROUP BY subcategoryName
ORDER BY subcategoryName
otherwise take query1 result .
The problem is that if we do not refactor your project, then you always have to evaluate query1 and see whether it contains All or not. If it does not contain All, then you need to evaluate query2 as well. This can hardly be optimized, let's see a few approaches:
Quickening query1
Since All might be not be the very last evaluated element, adding it to the filter and limiting it is a good idea to quicken query1:
SELECT
COUNT(*)
FROM
phonebook.newsms_subscription
INNER JOIN bdsubcategory ON bdsubcategory.subcategoryID = newsms_subscription.subcategoryID
INNER JOIN newsms_client ON newsms_subscription.clientID =newsms_client.clientID
INNER JOIN newsms_person ON newsms_subscription.personID = newsms_person.personID
WHERE
newsms_subscription.isActive = 1 AND
newsms_person.personID = '856' AND
bdsubcategory.subcategoryName = 'ALL'
LIMIT 0, 1
So, you could create a stored procedure which evaluates query1' (query1' is the quickened version of query1, as seen above) and if there is a result, then we need to execute query1. Otherwise we need to execute query2. This way you still execute two queries, but the first query is optimized.
Refactoring
Note that the second query does not change. You could create a table where you could cache its results, using a periodic job. Then, you could skip the second table to
SELECT ID, Name
FROM MyNewTable;
without the many joins. You would also cache the results of the first query into a table where the items having ALL would be stored and query that table.
One option would be to use a CASE.
Change this:
newsms_person.personID = '856'
To this:
'Y' = CASE WHEN UPPER('856') = 'ALL' THEN 'Y'
WHEN newsms_person.personID = '856' THEN 'Y'
ELSE 'N' END
Alternatively, a stored procedure could be used to first validate whether the personID seems valid, then returns the appropriate data.
I have a table with exchange rate like below
And I am using the maxofdate to pick all these values based on currency code. But the query is giving blank.
Select USDAMOUNT * dbo.EXCHANGERATEAMT
from dbo.Amount_monthly
Left Join dbo.EXCHANGERATE on dbo.Amount_monthly.Currencycode=dbo.EXCHANGERATE.fromcurrencycode
WHERE ValidToDateTime = (Select MAX(ValidToDateTime) from dbo.EXCHANGERATE)
AND dbo.EXCHANGERATE.EXCHANGERATETYPECODE = 'DAY'
Using this statement
CONVERT(DATE,ValidToDateTime) = CONVERT(DATE,GETDATE()-1)
instead of subquery is giving me expected result.
Can someone correct this.
thanks in advance.
If I understand correctly, you need two things. First, the condition for the max() needs to match the condition in the outer query. Second, if you really want a left join, then conditions on the second table need to go in the on clause.
The resulting query looks like:
Select . . .
from dbo.Amount_monthly am Left Join
dbo.EXCHANGERATE er
on am.Currencycode = er.fromcurrencycode and
er.ValidToDateTime = (Select max(er2.ValidToDateTime)
from dbo.EXCHANGERATE er2
where er2.EXCHANGERATETYPECODE = 'DAY'
) and
er.EXCHANGERATETYPECODE = 'DAY';
I would write this using window functions, but that is a separate issue.
Try removing WHERE clause for ValidToDateTime and include it in the JOIN as AND condition
SELECT USDAMOUNT * dbo.EXCHANGERATEAMT
FROM dbo.Amount_monthly
LEFT JOIN dbo.EXCHANGERATE
ON dbo.Amount_monthly.Currencycode = dbo.EXCHANGERATE.fromcurrencycode
AND ValidToDateTime = (SELECT MAX(ValidToDateTime) --remove WHERE clause
FROM dbo.EXCHANGERATE)
AND dbo.EXCHANGERATE.EXCHANGERATETYPECODE = 'DAY';
I cleaned up your query a bit: as the other folks mentioned you needed to close the parentheses around the MAX(Date) sub-query, and if you reference a LEFT JOINed table in the WHERE clause, it behaves like an INNER JOIN, so I changed to in INNER. You also had "dbo" sprinkled in as a field prefix, but that (the namespace) only prefixes a database, not a field. I added the IS NOT NULL check just to avoid SQL giving the "null values were eliminated" SQL warning. I used the aliases "am" for the first table and "er" for the 2nd, which makes it more readable:
SELECT am.USDAMOUNT * er.EXCHANGERATEAMT
FROM dbo.Amount_monthly am
JOIN dbo.EXCHANGERATE er
ON am.Currencycode = er.fromcurrencycode
WHERE er.ValidToDateTime = (SELECT MAX(ValidToDateTime) FROM dbo.EXCHANGERATE WHERE ValidToDateTime IS NOT NULL)
AND er.EXCHANGERATETYPECODE = 'DAY'
If you're paranoid like I am, you might also want to make sure the exchange rate is not zero to avoid a divide-by-zero error.
I am working on a query for a datatable and I can't seem to get it to display how I want, I don't know if this is even possible in SQL What I am looking to do is get a query to respond with ideally an extra column of Boolean type.
Currently I can run two queries and they both work perfectly but I can't work out how to join them together bellow is the code from my first query what this does is return beers a user has tried this works fine and as expected and returns as expected.
SELECT *
FROM keg.beer
JOIN keg.userbeer
ON beer.id = userbeer.beer_id
WHERE userbeer.username_id = 1;
The second query is even simpler and is just a select getting the list of beers.
SELECT * FROM keg.beer
What I want to do is run a query and have it return a list of beers with a Boolean value if the user has tried it or not.
You're not going to run into too many scenarios for "Desired Results" that can't be produced with plain 'ol SQL. In this case you'll use a CASE statement to determine if the person has tried a beer. You'll also want a LEFT OUTER JOIN so you don't drop records coming from your beer table when your filtered userid doesn't have a userbeer record for that beer:
SELECT
beer.name,
beer.id,
beer.country,
CASE WHEN userbeer.username_id IS NULL THEN 0 ELSE 1 END AS user_tried_beer_boolean
FROM keg.beer
LEFT OUTER JOIN keg.userbeer
ON beer.id = userbeer.beer_id
AND userbeer.username_id = 1;
As #SeanLange mentioned in the comments here, the restriction of the WHERE statement for the userid would cause records to be dropped that you want in your result set, so we move the restriction of username_id = 1 to the ON portion of the LEFT OUTER JOIN so that the userbeer table results are restricted to just that user before it's joined to the beer table.
Now I need a drink.
SELECT b.id,
b.name,
CASE WHEN u.username_id IS NOT NULL THEN TRUE ELSE FALSE END AS userdrankbeer
FROM keg.beer b
LEFT JOIN ( SELECT * FROM keg.userbeer WHERE username_id = 1 ) u
ON beer.id = userbeer.beer_id
;
I am trying to build an access query with multiple criteria. The table to be queried is "tblVendor" which has information about vendor shipment data as shown below:
The second table is "tblSchedule" which has the schedule for each Vendor cutoff date. This table has cutoff dates for data analysis.
For each vendor, I need to select records which have the ShipDate >= CutoffDate. Although not shown in the data here, it may be possible that multiple vendors have same CutoffDate.
For small number of records in "tblCutoffdate", I can write a query which looks like:
SELECT tblVendors.ShipmentId, tblVendors.VendorNumber, tblVendors.VendorName,
tblVendors.Units, tblVendors.ShipDate
FROM tblVendors INNER JOIN tblCutoffDate ON tblVendors.VendorNumber =
tblCutoffDate.VendorNumber
WHERE (((tblVendors.VendorNumber) In (SELECT VendorNumber FROM [tblCutoffDate] WHERE
[tblCutoffDate].[CutoffDate] = #2/1/2014#)) AND ((tblVendors.ShipDate)>=#2/1/2014#)) OR
(((tblVendors.VendorNumber) In (SELECT VendorNumber FROM [tblCutoffDate] WHERE
[tblCutoffDate].[CutoffDate] = #4/1/2014#)) AND ((tblVendors.ShipDate)>=#4/1/2014#));
As desired, the query gives me a result which looks like:
What concerns me now is that I have a lot of records being added to the "tblCutoffDate" which makes it difficult for me to hardcode the dates in the query. Is there a better way to write the above SQL statement without any hardcoding?
You might try something like -- this should handle vendors having no past cutoff,
or those having no future cutoff
"today" needs a suitable conversion to just date w/o time
comparison "=" may go on both, or one, or none Max/Min
"null" may be replaced by 1/1/1900 and 12/31/3999 in Max/Min
SELECT tblvendors.shipmentid,
tblvendors.vendornumber,
tblvendors.vendorname,
tblvendors.units,
tblvendors.shipdate
FROM tblvendors
LEFT JOIN
( SELECT vendornum,
Max( iif cutoffdate < today, cutoffdate, null) as PriorCutoff,
Min( iif cutoffdate >= today, cutoffdate, null) as NextCutoff
FROM tblcutoffdate
GROUP BY vendornum
) as VDates
ON vendornumber = vendornum
WHERE tblvendors.shipdate BETWEEN PriorCutoff and NextCutoff
ORDER BY vendornumber, shipdate, shipmentid
A simpler WHERE clause should give you what you want.
SELECT
v.ShipmentId,
v.VendorNumber,
v.VendorName,
v.Units,
v.ShipDate
FROM
tblVendors AS v
INNER JOIN tblCutoffDate AS cd
ON v.VendorNumber = cd.VendorNumber
WHERE v.ShipDate >= cd.CutoffDate;
I want to count how many records from another table in the same select statement , i used Left join
and in the select statement i put count(ag.*)
see the
Example :
$q = Doctrine_Query::create()
->select("a.answer_id,a.date_added , count(ag.content_id) AS agree_count")
->from('Answer a')
->leftJoin("a.Agree ag ON a.answer_id = ag.content_id AND ag.content_type = 'answer' ")
->where('a.question_id= ? ', $questionId)
But its only returning the first record, can i Fix that? or to make another table and make it only for counting ?
You are missing a GROUP BY in your query.
More infos here.
When you don't have a GROUP BY clause, it's normal to get only one row.
Count(*) will only return one record if you don't use Group By. You are asking it to count all the records, so there can be only one result.
The count() SQL function changes how results are returned from the database - without a GROUP BY the database will only return one record, regardless of other colums in the SELECT.
if you add:
group by a.answer_id
to the end of your SQL query, that might DWYM.