A clause used in SQL SELECT statements to sort query results.

learn more… | top users | synonyms (1)

3
votes
2answers
88 views

Optmizing ORDER BY

I'm new to MySQL and have written the following query (see below). PROBLEM: The query returns accurate data but takes about 40 seconds to execute. However, When I remove the ORDER BY part, it takes ...
0
votes
1answer
47 views

MYSQL ORDER BY Performance

We have a query like this: SELECT PROJECT.PROJECTID, REQUEST.REQUESTID, SAMPLE.SAMPLEID,SAMPLE.OTHERSAMPLEID, ILLUMINASEQPROTOCOL2.SAMPLEID FROM ILLUMINASEQPROTOCOL2, PROJECT, SAMPLE, ...
0
votes
1answer
81 views

How to sort query filename output like Windows explorer?

i would like to order my query output the way Windows Explorer does. First special characters like _, then the numbers, and the letters last. _ttt.bmp 0.gif bbb.png
0
votes
1answer
46 views

Filter and then sort products by availability

I have table with products. Each product can be avaible in 1+ suppliers, so product can be present multiple times. products - id_productSupplier (primary key) - id_product (foreign key) - ...
0
votes
1answer
32 views

MySQL order of query

My query return like this. 12 14 14 99 78 78 54 I want result to be sorted so that no same number comes consecutively in the result. The result that I want is like this. 12 14 99 14 78 54 78
2
votes
0answers
48 views

How to order by fields of joined table while selecting for update?

For selecting some rows of table Fwt_Chipkarte for update I use the following SQL statement (IBM DB2): SELECT o.Archiviert, o.Id, o.IdComm, o.Kartennummer, o.Konto, o.LetzteAenderung, o....
2
votes
0answers
123 views

Schema for user drag and drop ordering

I'm trying to work out the schema for a system where users will be able to order items in an (unlimited length) list by drag and drop. Is there any kind of standard way of storing this ordering ...
1
vote
0answers
10 views

MariaDB / mYSQL Order BY PrimaryKey DESC vs DESC set by Default

What do you guys think about: After each query, I put "Order BY PrimaryKey DESC" VS I set "PrimaryKey Sort by DESC Default" and each query I don't need to put Order By there. Which one will be ...
1
vote
0answers
342 views

Performance hits with MySQL Left Joins and Order By

There are a lot of questions out there regarding this issue, but most answers seem to be very case-specific. I've tried to make this general so it'll help others too. The Issue We have a smallish ...
1
vote
0answers
24 views

Custom cycling order in MySQL

Having following Foo table: id | name | group ===|=========|====== 1 | "John" | 1 2 | "Paul" | 1 3 | "Marry" | 1 4 | "Josh" | 1 5 | "Mike" | 2 6 | "Kevin" | 2 7 | "Ramon" | 2 8 | "Kim" ...
1
vote
0answers
117 views

PostgreSQL query slow when using tsvector and ORDER BY despite having index

Running on a large database (around 1.5G) The following query takes about 70 seconds to run, SELECT x FROM DBText x WHERE x.status = 2 AND x.publishedTime < 4574590406397 AND x.service = '...
1
vote
0answers
56 views

Slow MySQL Query when Ordering

This query takes around 2 seconds when the order by is included, without the order it takes less than a tenth of a second. The field that is doing the sorting, qc_products.addedDate, is an index and ...
1
vote
0answers
558 views

group by and order by making query very slow in mysql?

Query works fast: select SQL_NO_CACHE users.id, users.name from useres left join user_statistics on users.id = user_statistics.user_id where users.is_deleted = 0 group by users.id ...
1
vote
0answers
116 views

MySQL query with order by decreased performance

Here is my schema: CREATE TABLE `UserMst` ( `UserID` mediumint(8) unsigned NOT NULL AUTO_INCREMENT, `EMailID` varchar(50) DEFAULT NULL, `UserName` varchar(20) DEFAULT NULL, `FullName` ...
1
vote
0answers
381 views

MySQL GROUP BY and ORDER BY giving inconsistent results

I'm currently working with WordPress, and I've added a new meta value which is a number between 0 and 30. Zero is ignored and up to 30 need to be organised in order and only the latest (based on the ...
0
votes
0answers
46 views

Mysql: slow down with order by, global database problem

i create nasty query for testing reasons. Only for speed testing. EXPLAIN SELECT m.post_id FROM wp_postmeta m LEFT JOIN wp_postmeta mi ON m.`post_id` = mi.`post_id` LEFT JOIN wp_postmeta md ON (md.`...
0
votes
0answers
32 views

Which of these two queries is better - can be optimized more?

With regards to the usage of the IF statement, which is better to use? Query #1: SELECT whatever FROM auctions AS a LEFT JOIN ............... WHERE ............... ORDER BY IF(a....
0
votes
0answers
712 views

Using an enum as part of an index definition

When I use an ENUM column in a table the ORDER BY uses the ordinal of the ENUM not its value. I wasn't aware of that. So my question is what are the subtle issues when an ENUM is part of an index ...
0
votes
0answers
271 views

Slow query with ORDER BY with index created (more than 4mins on 0.6million records

I ran into a very weird query performance situation. If I run this query without order by, it finish in millsecs, with order by, it ends up with more than 4mins. EXPLAIN SELECT `book_book`.`id`, `...