I tried to run the following query in my Cloud VPS cPanel phpMyadmin
SELECT bankcode, bankname
FROM newbankdetails
WHERE
type='DB' AND
bankcode IN ( SELECT drawingbankname
FROM dd1
WHERE entrydate BETWEEN '01/04/2014' AND '30/04/2014'
AND paymentmode='DD'
AND state='TAMIL NADU' )
It takes very very very long time nearly 5 to 6 hours and says out of time or keeps running for days and don't show any error also don't show results.
Whereas it works perfectly in my local machine xampp
It happens only when working on large size tables like 12GB and around like that
How to speed it up and display the result as it displays instantly in localhost xampp
I think, replacing IN with a LEFT JOIN can make more sense, like this:
SELECT
bankcode, bankname
FROM
newbankdetails nd
LEFT JOIN
dd1 ON nd.bankcode = dd1.drawingbankname
WHERE
nd.type='DB'
AND
dd1.entrydate BETWEEN '01/04/2014' AND '30/04/2014'
AND
dd1.paymentmode = 'DD'
AND
dd1.state = 'TAMIL NADU'
I can't test it, But I think with dd1.paymentmode = 'DD' automatically removes rows of dd1.paymentmode IS NULL because of using LEFT JOIN.
First you should use EXPLAIN QUERY (https://dev.mysql.com/doc/refman/5.0/en/using-explain.html)
That will give you information about what is slow.
Your problem seems to be related to the size of the table. On your localhost you may have a small table, but in production it is very large. Also put an index on the first table on nd.bankcode.
You should try to remove the subselect, and use a JOIN instead.
Also, you should put indexes on the columns you use for search.
Put an index on drawingbankname, entrydate, paymentmode, state. Put also an index on nd.backcode .
Column drawingbankname is varchar, you should convert it to fixed char.
Remove the subselect and use JOIN.
Use EXPLAIN after the changes to see progress.
Related
Here is my query for a maintenance dates list.
SELECT `checkdates`.`checkdateplanneddate`, `checkdates`.`checkdatevehicle`, `checktypes`.`checktype`, `checktypes`.`emailto`, `checktypes`.`daysnotice`
FROM `checkdates`
, `checktypes`
WHERE `checktypes`.`checktype` = `checkdates`.`checkdatechecktype`;
The idea is..
Everyday the server will email customers to let them know which checkdates are coming, based on the days notice that is set for that type of check. (see image)
Currently it is showing all checkdates.
All i need to do is filter the list so it only shows the dates that are
"Todays date plus checktypes.daysnotice"
I have tried many different queries, but cannot seem to get the right combo.
Thank you in advance
I have attached an image to show that the data is available
If I understand your question correctly, and assuming that you are running MySQL (as the use of backticks for quoting and the phpmyadmin screen copy indicate), you can use date arithmetics as follows:
SELECT cd.checkdateplanneddate, cd.checkdatevehicle, ct.checktype, ct.emailto, ct.daysnotice
FROM checkdates cd
INNER JOIN checktypes ct ON ct.checktype = cd.checkdatechecktype
WHERE cd.checkdateplanneddate = current_date + interval ct.daysnotice day
The where condition implements the desired logic.
Side notes:
Use standard, explicit joins! Implicit joins (with commas in the from clause) is a very old syntax, that should not be used in new code
Table aliases make the query easier to write and read
I have a query that works when I troubleshoot this within my code on my local pc, it works perfectly but the moment I put this up on the live server the query fails for some reason, I think, but I'm not sure, that this boils down to the date fields somehow but honestly I have no idea why it's failing on the server. I have tried the sql functions Date, date_to_string and my dates are in the format '2019-03-08' please assist, my query is as per below.
select posted_ads.id, posted_ads.title,
posted_ads.description, posted_ads.price,
posted_ads.datePosted,
posted_ads.adCategory,
posted_ads.adSuspended, posted_ads.suspensionEmailSent,
posted_ads.adSuspensionReason, posted_ads_images.id, posted_ads_images.imageName,
posted_ads_images.type, posted_ads_images.adID
from posted_ads inner join
posted_ads_images
on posted_ads.id = posted_ads_images.adID
where title like '%mechanic%' and
posted_ads.adExpired = 0 and
posted_ads.datePosted between '2018-12-09' and '2019-03-09'
group by posted_ads.id
limit 6 offset 6
Can anyone please advise me on this error...
The database has 40,000 news stories but only the fields 'story' is large,
'old' is a numeric value 0 or 1,
'title' and 'shortstory' are very short or NULL.
any advice appreciated. This is the result of running a search database query.
Error: MySQL client ran out of memory
Statement: SELECT news30_access.usehtml, old, title, story, shortstory, news30_access.name AS accessname, news30_users.user AS authorname, timestamp, news30_story.id AS newsid FROM news30_story LEFT JOIN news30_users ON news30_story.author = news30_users.uid LEFT JOIN news30_access ON news30_users.uid = news30_access.uid WHERE title LIKE ? OR story LIKE ? OR shortstory LIKE ? OR news30_users.user LIKE ? ORDER BY timestamp DESC
The simple answer is: don't use story in the SELECT clause.
If you want the story, then limit the number of results being returned. Start with, say, 100 results by adding:
limit 100
to the end of the query. This will get the 100 most recent stories.
I also note that you are using like with story as well as other string columns. You probably want to be using match with a full text index. This doesn't solve your immediate problem (which is returning too much data to the client). But, it will make your queries run faster.
To learn about full text search, start with the documentation.
I'm using the Wordnet SQL database from here: http://wnsqlbuilder.sourceforge.net
It's all built fine and users with appropriate privileges have been set.
I'm trying to find synonyms of words and have tried to use the two example statements at the bottom of this page: http://wnsqlbuilder.sourceforge.net/sql-links.html
SELECT synsetid,dest.lemma,SUBSTRING(src.definition FROM 1 FOR 60) FROM wordsXsensesXsynsets AS src INNER JOIN wordsXsensesXsynsets AS dest USING(synsetid) WHERE src.lemma = 'option' AND dest.lemma <> 'option'
SELECT synsetid,lemma,SUBSTRING(definition FROM 1 FOR 60) FROM wordsXsensesXsynsets WHERE synsetid IN ( SELECT synsetid FROM wordsXsensesXsynsets WHERE lemma = 'option') AND lemma <> 'option' ORDER BY synsetid
However, they never complete. At least not in any reasonable amount of time and I have had to cancel all of the queries. All other queries seem to work find and when I break up the second SQL example, I can get the individual parts to work and complete in reasonable times (about 0.40 seconds)
When I try and run the full statement however, the MySQL command line client just hangs.
Is there a problem with this syntax? What is causing it to take so long?
EDIT:
Output of "EXPLAIN SELECT ..."
Output of "EXPLAIN EXTENDED ...; SHOW WARNINGS;"
I did more digging and looking into the various statements used and found the problem was in the IN command.
MySQL repeats the statement for every single row in the database. This is the cause of the hang, as it had to run through hundreds of thousands of records.
My remedy to this was to split the command into two separate database calls first getting the synsets, and then dynamically creating a bound SQL string to look for the words in the synsets.
Due to an older version of MySQL I'm having to use some pretty outdated methods to get things done.
At the moment I am trying to copy similar rows to another table based on a few distinct columns. The table holddups will be taking data from assets where the SKU and Description match those of one in holdkey. The command I'm running is:
INSERT INTO holddups
SELECT *
FROM assets, holdkey
WHERE assets.SKU = holdkey.SKU
AND assets.Description = holdkey.Description
And the error I'm getting is:
#1136 - Column count doesn't match value count at row 1
I hope this is enough to sort this all out, but if not feel free to ask more.
Selecting just * will take all columns from assets and holdkey and try to put it in holdups. But holdups does not have that much columns. Using assets.*will only take all columns of assets and that is what you want, right?
INSERT INTO holddups
SELECT assets.*
FROM assets, holdkey
WHERE assets.SKU = holdkey.SKU
AND assets.Description = holdkey.Description