Example:
SELECT `cat`.`id_catalog`, COUNT(parent.id_catalog) - 1) AS `level` FROM `tbl_catalog` AS `cat`, `tbl_catalog` AS `parent` WHERE (cat.`left` BETWEEN parent.`left` AND parent.`right`) GROUP BY `cat`.`id_catalog` ORDER BY `cat`.`left` ASC
It doesn't seem to work if it use ZF. ZF create this query with join only. How to create the select without join in ZF_DB.
By the way may be I do smth wrong in this query. It is simple nested set DB with parent, left and right fields. Perhaps there are another way to use join to get deep for some node. Anyway it would be interesting to get answer for both way:)
Thanks in advance to all who looks it through:)
Related
I am trying to implement full outer join using tJoin component but I am not getting as expected results. Could anyone help me on this?
Screenshot of tJoin:
In fact Talend does not implement a full join, but you can achieve it by reading your inputs twice, performing a left and a right join for each reading, then unite the two flows using tUnite and get unique rows by tUniqRow
I think tJoin is for LEFT or INNER joins.
For FULL joins you need to use a tMap.
Regards,
TRF
I have a mongo database and I'm trying to write an Eloquent code to change some fields before using them in WHERE or ORDER BY clauses. something like this SQL query:
Select ag.*, ht.*
from agency as ag inner join hotel as ht on ag.hotel_id = ht.id
Where ht.title = 'OrangeHotel'
-- or --
Select ag.*, ht.*
from agency as ag inner join hotel as ht on ag.hotel_id = ht.id
Order by ht.title
sometimes there is no other table and I just need to use calculated field in Where or Order By clause:
Select *
from agency
Where func(agency_admin) = 'testAdmin'
Select *
from agency
Order by func(agency_admin)
where func() is my custom function.
any suggestion?
and I have read Laravel 4/5, order by a foreign column for half of my problem, but I don't know how can I use it.
For the first query: mongodb only support "join" partially with the aggregation pipeline, which limits your aggregation in one collection. For "join"s between different collections/tables, just select from collections one by one, first the one containing the "where" field, then the one who should "join" with the former, and so on.
The second question just puzzled me for some minutes until I see this question and realized it's the same as your first question: sort the collection containing your sort field and retrive some data, then go to another.
For the 3rd question, this question should serve you well.
I have a custom query along these lines. I get the list of orderIds from outside. I have the entire order object list with me, so I can change the query in any way, if needed.
#Query("SELECT p FROM Person p INNER JOIN p.orders o WHERE o.orderId in :orderIds)")
public List<Person> findByOrderIds(#Param("orderIds") List<String> orderIds);
This query works fine, but sometimes it may have anywhere between 50-1000 entries in the orderIds list sent from outside function. So it becomes very slow, taking as much as 5-6 seconds which is not fast enough. My question is, is there a better, faster way to do this? When I googled, and on this site, I see we can use ANY, EXISTS: Postgresql: alternative to WHERE IN respective WHERE NOT IN or create a temporary table: https://dba.stackexchange.com/questions/12607/ways-to-speed-up-in-queries-under-postgresql or join this to VALUES clause: Alternative when IN clause is inputed A LOT of values (postgreSQL). All these answers are tailored towards direct SQL calls, nothing based on JPA. ANY keyword is not supported by spring-data. Not sure about creating temporary tables in custom queries. I think I can do it with native queries, but have not tried it. I am using spring-data + OpenJPA + PostgresSQL.
Can you please suggest a solution or give pointers? I apologize if I missed anything.
thanks,
Alice
You can use WHERE EXISTS instead of IN Clause in a native SQL Query as well as in HQL in JPA which results in a lot of performance benefits. Please see sample below
Sample JPA Query:
SELECT emp FROM Employee emp JOIN emp.projects p where NOT EXISTS (SELECT project from Project project where p = project AND project.status <> 'Active')
My scenario is like this:
I have a couple of views in my databse (SQL Server 2005).
These views are queried from Excel across the organization.
My goal is to identify those views which have not been used by anyone for a long time.
Is there a way to count the number of times a view has been requested since a specific date?
Thanks
Avi
You can use following query to get some queries those executed. You can place "Like" operator in dest.text field to check for views.
SELECT deqs.last_execution_time AS [Time], dest.text AS [Query]
FROM sys.dm_exec_query_stats AS deqs
CROSS APPLY sys.dm_exec_sql_text(deqs.sql_handle) AS dest
ORDER BY deqs.last_execution_time DES
I think a combination of DMVs and sysobjects could tell you this. This should hopefully show you all queries run that refer to a view, the name of the view, when it was last run etc.
SELECT s2.text AS Query,
so.name AS ViewName,
creation_time,
last_execution_time,
execution_count
FROM sys.dm_exec_query_stats AS s1
CROSS APPLY sys.Dm_exec_sql_text(sql_handle) AS s2
INNER JOIN sys.objects so
ON so.object_id = s2.objectid
AND so.type = 'V'
I don't think that you'll be able to do this unless you are running a trace 24/7. You could turn on auditing in order to monitor it. But, it would be a big task for however has to read through the logs.
I usually use ORM instead of SQL and I am slightly out of touch on the different JOINs...
SELECT `order_invoice`.*
, `client`.*
, `order_product`.*
, SUM(product.cost) as net
FROM `order_invoice`
LEFT JOIN `client`
ON order_invoice.client_id = client.client_id
LEFT JOIN `order_product`
ON order_invoice.invoice_id = order_product.invoice_id
LEFT JOIN `product`
ON order_product.product_id = product.product_id
WHERE (order_invoice.date_created >= '2009-01-01')
AND (order_invoice.date_created <= '2009-02-01')
GROUP BY `order_invoice`.`invoice_id`
The tables/ columns are logically names... it's an shop type application... the query works... it's just very very slow...
I use the Zend Framework and would usually use Zend_Db_Table_Row::find(Parent|Dependent)Row(set)('TableClass') but I have to make lots of joins and I thought it'll improve performance by doing it all in one query instead of hundreds...
Can I improve the above query by using more appropriate JOINs or a different implementation? Many thanks.
The query is wrong, the GROUP BY is wrong. All columns in the SELECT-part that are not in an aggregate function, have to be in the GROUP BY. You mention only one column.
Change the SQL Mode, set it to ONLY_FULL_GROUP_BY.
When this is done and you have a correct query, use EXPLAIN to find out how the query is executed and what indexes are used. Then start optimizing.