Search Results

Search found 17347 results on 694 pages for 'parameterized query'.

Page 2/694 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

• SQLAuthority News – Download Whitepaper – Understanding and Controlling Parallel Query Processing in SQL Server

  - by pinaldave

  My recently article SQL SERVER – Reducing CXPACKET Wait Stats for High Transactional Database has received many good comments regarding MAXDOP 1 and MAXDOP 0. I really enjoyed reading the comments as the comments are received from industry leaders and gurus. I was further researching on the subject and I end up on following white paper written by Microsoft. Understanding and Controlling Parallel Query Processing in SQL Server Data warehousing and general reporting applications tend to be CPU intensive because they need to read and process a large number of rows. To facilitate quick data processing for queries that touch a large amount of data, Microsoft SQL Server exploits the power of multiple logical processors to provide parallel query processing operations such as parallel scans. Through extensive testing, we have learned that, for most large queries that are executed in a parallel fashion, SQL Server can deliver linear or nearly linear response time speedup as the number of logical processors increases. However, some queries in high parallelism scenarios perform suboptimally. There are also some parallelism issues that can occur in a multi-user parallel query workload. This white paper describes parallel performance problems you might encounter when you run such queries and workloads, and it explains why these issues occur. In addition, it presents how data warehouse developers can detect these issues, and how they can work around them or mitigate them. To review the document, please download the Understanding and Controlling Parallel Query Processing in SQL Server Word document. Note: Above abstract has been taken from here. The real question is what does the parallel queries has made life of DBA much simpler or is it looked at with potential issue related to degradation of the performance? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQL White Papers, SQLAuthority News, T SQL, Technology

  Read the article

• SQL SERVER – MAXDOP Settings to Limit Query to Run on Specific CPU

  - by pinaldave

  This is very simple and known tip. Query Hint MAXDOP – Maximum Degree Of Parallelism can be set to restrict query to run on a certain CPU. Please note that this query cannot restrict or dictate which CPU to be used, but for sure, it restricts the usage of number of CPUs in a single [...]

  Read the article

• SQL SERVER – Quiz and Video – Introduction to Hierarchical Query using a Recursive CTE

  - by pinaldave

  This blog post is inspired from SQL Queries Joes 2 Pros: SQL Query Techniques For Microsoft SQL Server 2008 – SQL Exam Prep Series 70-433 – Volume 2.[Amazon] | [Flipkart] | [Kindle] | [IndiaPlaza] This is follow up blog post of my earlier blog post on the same subject - SQL SERVER – Introduction to Hierarchical Query using a Recursive CTE – A Primer. In the article we discussed various basics terminology of the CTE. The article further covers following important concepts of common table expression. What is a Common Table Expression (CTE) Building a Recursive CTE Identify the Anchor and Recursive Query Add the Anchor and Recursive query to a CTE Add an expression to track hierarchical level Add a self-referencing INNER JOIN statement Above six are the most important concepts related to CTE and SQL Server.  There are many more things one has to learn but without beginners fundamentals one can’t learn the advanced  concepts. Let us have small quiz and check how many of you get the fundamentals right. Quiz 1) You have an employee table with the following data. EmpID FirstName LastName MgrID 1 David Kennson 11 2 Eric Bender 11 3 Lisa Kendall 4 4 David Lonning 11 5 John Marshbank 4 6 James Newton 3 7 Sally Smith NULL You need to write a recursive CTE that shows the EmpID, FirstName, LastName, MgrID, and employee level. The CEO should be listed at Level 1. All people who work for the CEO will be listed at Level 2. All of the people who work for those people will be listed at Level 3. Which CTE code will achieve this result? WITH EmpList AS (SELECT Boss.EmpID, Boss.FName, Boss.LName, Boss.MgrID, 1 AS Lvl FROM Employee AS Boss WHERE Boss.MgrID IS NULL UNION ALL SELECT E.EmpID, E.FirstName, E.LastName, E.MgrID, EmpList.Lvl + 1 FROM Employee AS E INNER JOIN EmpList ON E.MgrID = EmpList.EmpID) SELECT * FROM EmpList WITH EmpListAS (SELECT EmpID, FirstName, LastName, MgrID, 1 as Lvl FROM Employee WHERE MgrID IS NULL UNION ALL SELECT EmpID, FirstName, LastName, MgrID, 2 as Lvl ) SELECT * FROM BossList WITH EmpList AS (SELECT EmpID, FirstName, LastName, MgrID, 1 as Lvl FROM Employee WHERE MgrID is NOT NULL UNION SELECT EmpID, FirstName, LastName, MgrID, BossList.Lvl + 1 FROM Employee INNER JOIN EmpList BossList ON Employee.MgrID = BossList.EmpID) SELECT * FROM EmpList 2) You have a table named Employee. The EmployeeID of each employee’s manager is in the ManagerID column. You need to write a recursive query that produces a list of employees and their manager. The query must also include the employee’s level in the hierarchy. You write the following code segment: WITH EmployeeList (EmployeeID, FullName, ManagerName, Level) AS ( –PICK ANSWER CODE HERE ) SELECT EmployeeID, FullName, ” AS [ManagerID], 1 AS [Level] FROM Employee WHERE ManagerID IS NULL UNION ALL SELECT emp.EmployeeID, emp.FullName mgr.FullName, 1 + 1 AS [Level] FROM Employee emp JOIN Employee mgr ON emp.ManagerID = mgr.EmployeeId SELECT EmployeeID, FullName, ” AS [ManagerID], 1 AS [Level] FROM Employee WHERE ManagerID IS NULL UNION ALL SELECT emp.EmployeeID, emp.FullName, mgr.FullName, mgr.Level + 1 FROM EmployeeList mgr JOIN Employee emp ON emp.ManagerID = mgr.EmployeeId Now make sure that you write down all the answers on the piece of paper. Watch following video and read earlier article over here. If you want to change the answer you still have chance. Solution 1) 1 2) 2 Now compare let us check the answers and compare your answers to following answers. I am very confident you will get them correct. Available at USA: Amazon India: Flipkart | IndiaPlaza Volume: 1, 2, 3, 4, 5 Please leave your feedback in the comment area for the quiz and video. Did you know all the answers of the quiz? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

  Read the article

• SQL SERVER – Relationship with Parallelism with Locks and Query Wait – Question for You

  - by Pinal Dave

  Today, I have one very simple question based on following image. A full disclaimer is that I have no idea why it is like that. I tried to reach out to few of my friends who know a lot about SQL Server but no one has any answer. Here is the question: If you go to server properties and click on Advanced you will see the following screen. Under the Parallelism section if you noticed there are four options: Cost Threshold for Parallelism Locks Max Degree of Parallelism Query Wait I can clearly understand why Cost Threshold for Parallelism and Max Degree of Parallelism belongs to Parallelism but I am not sure why we have two other options Locks and Query Wait belongs to Parallelism section. I can see that the options are ordered alphabetically but I do not understand the reason for locks and query wait to list under Parallelism. Here is the question for you – Why Locks and Query Wait options are listed under Parallelism section in SQL Server Advanced Properties? Please leave a comment with your explanation. I will publish valid answers on this blog with due credit. Reference: Pinal Dave (http://blog.sqlauthority.com)   Filed under: PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

  Read the article

• Undocumented Query Plans: Equality Comparisons

  - by Paul White

  The diagram below shows two data sets, with differences highlighted: To find changed rows using TSQL, we might write a query like this: The logic is clear: join rows from the two sets together on the primary key column, and return rows where a change has occurred in one or more data columns.  Unfortunately, this query only finds one of the expected four rows: The problem, of course, is that our query does not correctly handle NULLs.  The ‘not equal to’ operators <> and != do not evaluate...(read more)

  Read the article

• specify query timeout when using toplink essential query hint

  - by yhzs8

  Hi, For glassfish v2, I have searched through the web and I cannot find anyway to specify query timeout when using TopLink essential query hint. We have another option to migrate to EclipseLink but that is not feasible. have tried the solution in http://forums.oracle.com/forums/thread.jspa?threadID=974732&tstart=-1 but it seems the DatabaseQuery which one could set a timeout value is actually for Toplink, not TopLink essential. Do we have some other way to instruct the JDBC driver for this timeout value other than the query hint? I need to do it on query-basis and not system-basis (which is just to change the value of DISTRIBUTED_LOCK_TIMEOUT)

  Read the article

• mysql query query

  - by nightcoder1

  basically i need to write a query for mysql, but i have no experience in this and i cant find good tutorials on the old tinternet. i have a table called rels with columns "hosd_id" "linkedhost_id" "text link" and a table called hostlist with columns "id" "hostname" all i am trying to achieve is a query which outputs the "hostname" and "linked_id" when "host_id" is equal to "id" any help or pointers on syntax or code would be helpfull, or even a good mysql query guide

  Read the article

• mod_rewrite to redirect URL with query string

  - by meeble

  I've searched all over stackoverflow, but none of the answers seem to be working for this situation. I have a lot of working mod_rewrite rules already in my httpd.conf file. I just recently found that Google had indexed one of my non-rewritten URLs with a query string in it: http://domain.com/?state=arizona I would like to use mod_rewrite to do a 301 redirect to this URL: http://domain.com/arizona The issue is that later on in my rewrite rules, that 2nd URL is being rewritten to pass query variables on to WordPress. It ends up getting rewritten to: http://domain.com/index.php?state=arizona Which is the proper functionality. Everything I have tried so far has either not worked at all or put me in an endless rewrite loop. This is what I have right now, which is getting stuck in a loop: RewriteCond %{QUERY_STRING} state=arizona [NC] RewriteRule .* http://domain.com/arizona [R=301,L] #older rewrite rule that passes query string based on URL: RewriteRule ^([A-Za-z-]+)$ index.php?state=$1 [L] which gives me an endless rewrite loop and takes me to this URL: http://domain.com/arizona?state=arizona I then tried this: RewriteRule .* http://domain.com/arizona? [R=301,L] which got rid of the query string in the URL, but still creates a loop.

  Read the article

• Combining two-part SQL query into one query

  - by user332523

  Hello, I have a SQL query that I'm currently solving by doing two queries. I am wondering if there is a way to do it in a single query that makes it more efficient. Consider two tables: Transaction_Entries table and Transactions, each one defined below: Transactions - id - reference_number (varchar) Transaction_Entries - id - account_id - transaction_id (references Transactions table) Notes: There are multiple transaction entries per transaction. Some transactions are related, and will have the same reference_number string. To get all transaction entries for Account X, then I would do SELECT E.*, T.reference_number FROM Transaction_Entries E JOIN Transactions T ON (E.transaction_id=T.id) where E.account_id = X The next part is the hard part. I want to find all related transactions, regardless of the account id. First I make a list of all the unique reference numbers I found in the previous result set. Then for each one, I can query all the transactions that have that reference number. Assume that I hold all the rows from the previous query in PreviousResultSet UniqueReferenceNumbers = GetUniqueReferenceNumbers(PreviousResultSet) // in Java foreach R in UniqueReferenceNumbers // in Java SELECT * FROM Transaction_Entries where transaction_id IN (SELECT * FROM Transactions WHERE reference_number=R Any suggestions how I can put this into a single efficient query?

  Read the article

• query optimization

  - by Gaurav

  I have a query of the form SELECT uid1,uid2 FROM friend WHERE uid1 IN (SELECT uid2 FROM friend WHERE uid1='.$user_id.') and uid2 IN (SELECT uid2 FROM friend WHERE uid1='.$user_id.') The problem now is that the nested query SELECT uid2 FROM friend WHERE uid1='.$user_id.' returns a very large number of ids(approx. 5000). The table structure of the friend table is uid1(int), uid2(int). This table is used to determine whether two users are linked together as friends. Any workaround? Can I write the query in a different way? Or is there some other way to solve this issue. I'm sure I am not the first person to face such a problem. Any help would be greatly appreciated.

  Read the article

• Why this query is so slow?

  - by Silver Light

  This query appears in mysql slow query log: it takes 11 seconds. INSERT INTO record_visits ( record_id, visit_day ) VALUES ( '567', NOW() ); The table has 501043 records and it's structure looks like this: CREATE TABLE IF NOT EXISTS `record_visits` ( `id` int(11) NOT NULL AUTO_INCREMENT, `record_id` int(11) DEFAULT NULL, `visit_day` date DEFAULT NULL, `visit_cnt` bigint(20) DEFAULT '1', PRIMARY KEY (`id`), UNIQUE KEY `record_id_visit_day` (`record_id`,`visit_day`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 ; What could be wrong? Why this INSERT takes so long?

  Read the article

• Is there any way to send a column value from outer query to inner sub query? [closed]

  - by chetan

  'Discussions' table schema title description desid replyto upvote downvote views browser used a1 none 1 1 12 - bad topic b2 a1 2 3 14 sql database a3 none 4 5 34 - crome b4 a3 3 4 12 The above table has two types of content types Main Topics and Comments. Unique content identifier 'desid' used to identify that its a main topic or a comment. 'desid' starts with 'a' for Main Topic and for comment 'desid' starts with 'b'. For comment 'replyto' is the 'desid' of main topic to which this comment is associated. I like to find out the list of the top main topics that are arranged on the basis of (upvote+downvote+visits+number of comments to it) addition. The following query gives top topics list in order of (upvote+downvote+visits) select * with highest number of upvote+downvote+views by query "select * from [DB_user1212].[dbo].[discussions] where desid like 'a%' order by (upvote+downvote+visited) desc For (comments+upvote+downvote+views ) I tried select * from [DB_user1212].[dbo].[discussions] where desid like 'a%' order by ((select count(*) from [DB_user1212].[dbo].[discussions] where replyto = desid )+upvote+downvote+visited) desc but it didn't work because its not possible to send desid from outer query to inner subquery. How to solve this? Please note that I want solution in query language only.

  Read the article

• Query Optimizing Request

  - by mithilatw

  I am very sorry if this question is structured in not a very helpful manner or the question itself is not a very good one! I need to update a MSSQL table call component every 10 minutes based on information from another table call materials_progress I have nearly 60000 records in component and more than 10000 records in materials_progress I wrote an update query to do the job, but it takes longer than 4 minutes to complete execution! Here is the query : UPDATE component SET stage_id = CASE WHEN t.required_quantity <= t.total_received THEN 27 WHEN t.total_ordered < t.total_received THEN 18 ELSE 18 END FROM ( SELECT mp.job_id, mp.line_no, mp.component, l.quantity AS line_quantity, CASE WHEN mp.component_name_id = 2 THEN l.quantity*2 ELSE l.quantity END AS required_quantity, SUM(ordered) AS total_ordered, SUM(received) AS total_received , c.component_id FROM line l LEFT JOIN component c ON c.line_id = l.line_id LEFT JOIN materials_progress mp ON l.job_id = mp.job_id AND l.line_no = mp.line_no AND c.component_name_id = mp.component_name_id WHERE mp.job_id IS NOT NULL AND (mp.cancelled IS NULL OR mp.cancelled = 0) AND (mp.manual_override IS NULL OR mp.manual_override = 0) AND c.stage_id = 18 GROUP BY mp.job_id, mp.line_no, mp.component, l.quantity, mp.component_name_id, component_id ) AS t WHERE component.component_id = t.component_id I am not going to explain the scenario as it too complex.. could somebody please please tell me what makes this query this much expensive and a way to get around it? Thank you very very much in advance!!!

  Read the article

• How can I track the last location of a shipment effeciently using latest date of reporting?

  - by hash

  I need to find the latest location of each cargo item in a consignment. We mostly do this by looking at the route selected for a consignment and then finding the latest (max) time entered against nodes of this route. For example if a route has 5 nodes and we have entered timings against first 3 nodes, then the latest timing (max time) will tell us its location among the 3 nodes. I am really stuck on this query regarding performance issues. Even on few hundred rows, it takes more than 2 minutes. Please suggest how can I improve this query or any alternative approach I should acquire? Note: ATA= Actual Time of Arrival and ATD = Actual Time of Departure SELECT DISTINCT(c.id) as cid,c.ref as cons_ref , c.Name, c.CustRef FROM consignments c INNER JOIN routes r ON c.Route = r.ID INNER JOIN routes_nodes rn ON rn.Route = r.ID INNER JOIN cargo_timing ct ON c.ID=ct.ConsignmentID INNER JOIN (SELECT t.ConsignmentID, Max(t.firstata) as MaxDate FROM cargo_timing t GROUP BY t.ConsignmentID ) as TMax ON TMax.MaxDate=ct.firstata AND TMax.ConsignmentID=c.ID INNER JOIN nodes an ON ct.routenodeid = an.ID INNER JOIN contract cor ON cor.ID = c.Contract WHERE c.Type = 'Road' AND ( c.ATD = 0 AND c.ATA != 0 ) AND (cor.contract_reference in ('Generic','BP001','020-543-912')) ORDER BY c.ref ASC

  Read the article

• End user query syntax?

  - by weberc2

  I'm making a command line tool that allows end users to query a statically-schemed database; however, I want users to be able to specify boolean matchers in their query (effectively things like "get rows where (field1=abcd && field2=efgh) || field3=1234"). I did Googling a solution, but I couldn't find anything suitable for end users--still, this seems like it would be a very common problem so I suspect there is a standard solution. So: What (if any) standard query "languages" are there that might be appropriate for end users? What (if any) de facto standards are there (for example, Unix tools that solve similar problems). Failing the previous two options, can you suggest a syntax that would be simple, concise, and easy to validate?

  Read the article

• Joining two queries into one query or making a sub-query

  - by gary A.K.A. G4

  I am having some trouble with the following queries originally done for some Access forms: SELECT qry1.TCKYEAR AS Yr, COUNT(qry1.SID) AS STUDID, qry1.SID AS MID, table_tckt.tckt_tick_no FROM table_tckt INNER JOIN qry1 ON table_tckt.tckt_SID = qry1.SID GROUP BY qry1.TCKYEAR, qry1.SID, table_tckt.tckt_tick_no HAVING (((table_tckt.tick_no)=[forms]![frmNAME]![cboNAME])); SELECT table_tckt.sid, FORMAT([tckt_iss_date], 'yyyy') AS TCKYEAR, table_tckt.tckt_tick_no, table_tckt.licstate FROM table_tckt WHERE (((table_tckt.licstate)<>"NA")); I am no longer working with Access, but JSP for the forms. I need to somehow either combine these two queries into one query or find another way to have a query 'query' another one.

  Read the article

• Help with SQL query (list strings and count in same query)

  - by Mestika

  Hi everybody, I’m working on a small kind of log system to a webpage, and I’m having some difficulties with a query I want to do multiple things. I have tried to do some nested / subqueries but can’t seem to get it right. I’ve two tables: User = {userid: int, username} Registered = {userid: int, favoriteid: int} What I need is a query to list all the userid’s and the usernames of each user. In addition, I also need to count the total number of favoriteid’s the user is registered with. A user who is not registered for any favorite must also be listed, but with the favorite count shown as zero. I hope that I have explained my request probably but otherwise please write back so I can elaborate. By the way, the query I’ve tried with look like this: SELECT user.userid, user.username FROM user,registered WHERE user.userid = registered.userid(SELECT COUNT(favoriteid) FROM registered) However, it doesn’t do the trick, unfortunately Kind regards Mestika

  Read the article

• Can this sql query be simplified?

  - by Bas

  I have the following tables: Person, {"Id", "Name", "LastName"} Sports, {"Id" "Name", "Type"} SportsPerPerson, {"Id", "PersonId", "SportsId"} For my query I want to get all the Persons that excersise a specific Sport whereas I only have the Sports "Name" attribute at my disposal. To retrieve the correct rows I've figured out the following queries: SELECT * FROM Person WHERE Person.Id in ( SELECT SportsPerPerson.PersonId FROM SportsPerPerson INNER JOIN Sports on SportsPerPerson.SportsId = Sports.Id WHERE Sports.Name = 'Tennis' ) AND Person.Id in ( SELECT SportsPerPerson.PersonId FROM SportsPerPerson INNER JOIN Sports on SportsPerPerson.SportsId = Sports.Id WHERE Sports.Name = 'Soccer' ) OR SELECT * FROM Person WHERE Id IN (SELECT PersonId FROM SportsPerPerson WHERE SportsId IN (SELECT Id FROM Sports WHERE Name = 'Tennis')) AND Id IN (SELECT PersonId FROM SportsPerPerson WHERE SportsId IN (SELECT Id FROM Sports WHERE Name = 'Soccer')) Now my question is, isn't there an easier way to write this query? Using just OR won't work because I need the person who play 'Tennis' AND 'Soccer'. But using AND also doesn't work because the values aren't on the same row.

  Read the article

• How to make this sub-sub-query work?

  - by Josh Weissbock

  I am trying to do this in one query. I asked a similar question a few days ago but my personal requirements have changed. I have a game type website where users can attend "classes". There are three tables in my DB. I am using MySQL. I have four tables: hl_classes (int id, int professor, varchar class, text description) hl_classes_lessons (int id, int class_id, varchar lessonTitle, varchar lexiconLink, text lessonData) hl_classes_answers (int id, int lesson_id, int student, text submit_answer, int percent) hl_classes stores all of the classes on the website. The lessons are the individual lessons for each class. A class can have infinite lessons. Each lesson is available in a specific term. hl_classes_terms stores a list of all the terms and the current term has the field active = '1'. When a user submits their answers to a lesson it is stored in hl_classes_answers. A user can only answer each lesson once. Lessons have to be answered sequentially. All users attend all "classes". What I am trying to do is grab the next lesson for each user to do in each class. When the users start they are in term 1. When they complete all 10 lessons in each class they move on to term 2. When they finish lesson 20 for each class they move on to term 3. Let's say we know the term the user is in by the PHP variable $term. So this is my query I am currently trying to massage out but it doesn't work. Specifically because of the hC.id is unknown in the WHERE clause SELECT hC.id, hC.class, (SELECT MIN(output.id) as nextLessonID FROM ( SELECT id, class_id FROM hl_classes_lessons hL WHERE hL.class_id = hC.id ORDER BY hL.id LIMIT $term,10 ) as output WHERE output.id NOT IN (SELECT lesson_id FROM hl_classes_answers WHERE student = $USER_ID)) as nextLessonID FROM hl_classes hC My logic behind this query is first to For each class; select all of the lessons in the term the current user is in. From this sort out the lessons the user has already done and grab the MINIMUM id of the lessons yet to be done. This will be the lesson the user has to do. I hope I have made my question clear enough.

  Read the article

• Date/time query from Access table ( last month)

  - by chupeman

  Hello, I am using the query builder from Visual Studio 2008 to extract data from an Access mdb ( 2003), but I can't make it to work with a datetime field. When I run it with a third party query app I have works fine, but when I try to implement it into visual studio I can't do it. What is the correct way to extract last month data? This is what I have: SELECT [Datos].[ID], [Datos].[E-mail Address], [Datos].[ZIP/Postal Code], [Datos].[Store], [Datos].[date], [Datos].[gender], [Datos].[age] FROM [Datos] WHERE ([Datos].[date] =<|Last month|>) Any help is appreciated. Thank you

  Read the article

• building SQL Query From another Query in php

  - by Nina

  Hello when I Try to built Query from another Query in php code I Faced some problem can you tell me why? :( code : $First="SELECT ro.RoomID,ro.RoomName,ro.RoomLogo,jr.RoomID,jr.MemberID,ro.RoomDescription FROM joinroom jr,rooms ro where (ro.RoomID=jr.RoomID)AND jr.MemberID = '1' "; $sql1 = mysql_query($First); $constract .= "ro.RoomName LIKE '%$search_each%'"; $constract="SELECT * FROM $sql1 WHERE $constract ";// This statment is Make error

  Read the article

• Convert this Linq query from query syntax to lambda expression

  - by Jinkinz

  I'm not sure I like linq query syntax...its just not my preference. But I don't know what this query would look like using lambda expressions, can someone help? from securityRoles in user.SecurityRoles from permissions in securityRoles.Permissions where permissions.SecurableEntity.Name == "Unit" && permissions.PermissionType.Name == "Read" orderby permissions.PermissionLevel.Value descending select permissions There is a many-to-many relationship between users and security roles that makes this extra confusing. Thanks! Kelly

  Read the article

• EF query to fluent nhibernate query

  - by Shlomi Levi

  I have EF Query: IEnumerable<Account> accounts = (from a in dc.Accounts join m in dc.GroupMembers on a.AccountID equals m.AccountID where m.GroupID == GroupID && m.IsApproved select a).Skip((_configuration.NumberOfRecordsInPage * (PageNumber - 1))) .Take(_configuration.NumberOfRecordsInPage); How to write it in fluent nhibernate query with Session.CreateCriteria<? (My problem is with Join) Regards,

  Read the article

• Optimize GROUP BY&ORDER BY query

  - by Jan Hancic

  I have a web page where users upload&watch videos. Last week I asked what is the best way to track video views so that I could display the most viewed videos this week (videos from all dates). Now I need some help optimizing a query with which I get the videos from the database. The relevant tables are this: video (~239371 rows) VID(int), UID(int), title(varchar), status(enum), type(varchar), is_duplicate(enum), is_adult(enum), channel_id(tinyint) signup (~115440 rows) UID(int), username(varchar) videos_views (~359202 rows after 6 days of collecting data, so this table will grow rapidly) videos_id(int), views_date(date), num_of_views(int) The table video holds the videos, signup hodls users and videos_views holds data about video views (each video can have one row per day in that table). I have this query that does the trick, but takes ~10s to execute, and I imagine this will only get worse over time as the videos_views table grows in size. SELECT v.VID, v.title, v.vkey, v.duration, v.addtime, v.UID, v.viewnumber, v.com_num, v.rate, v.THB, s.username, SUM(vvt.num_of_views) AS tmp_num FROM video v LEFT JOIN videos_views vvt ON v.VID = vvt.videos_id LEFT JOIN signup s on v.UID = s.UID WHERE v.status = 'Converted' AND v.type = 'public' AND v.is_duplicate = '0' AND v.is_adult = '0' AND v.channel_id <> 10 AND vvt.views_date >= '2001-05-11' GROUP BY vvt.videos_id ORDER BY tmp_num DESC LIMIT 8 And here is a screenshot of the EXPLAIN result: So, how can I optimize this?

  Read the article

• A typical mysql query( how to use subquery column into main query)

  - by I Like PHP

  I HAVE TWO TABLES shown below table_joining id join_id(PK) transfer_id(FK) unit_id transfer_date joining_date 1 j_1 t_1 u_1 2010-06-05 2010-03-05 2 j_2 t_2 u_3 2010-05-10 2010-03-10 3 j_3 t_3 u_6 2010-04-10 2010-01-01 4 j_5 NULL u_3 NULL 2010-06-05 5 j_6 NULL u_4 NULL 2010-05-05 table_transfer id transfer_id(PK) pastUnitId futureUnitId effective_transfer_date 1 t_1 u_3 u_1 2010-06-05 2 t_2 u_6 u_1 2010-05-10 3 t_3 u_5 u_3 2010-04-10 now i want to know total employee detalis( using join_id) which are currently working on unit u_3 . means i want only join_id j_1 (has transfered but effective_transfer_date is future date, right now in u_3) j_2 ( tansfered and right now in `u_3` bcoz effective_transfer_date has been passed) j_6 ( right now in `u_3` and never transfered) what i need to take care of below steps( as far as i know ) <1> first need to check from table_joining whether transfer_id is NULL or not <2> if transfer_id= is NULL then see unit_id=u_3 where joining_date <=CURDATE() ( means that person already joined u_3) <3> if transfer_id is NOT NULL then go to table_transfer using transfer_id (foreign key reference) <4> now see the effective_transfer_date regrading that transfer_id whether effective_transfer_date<=CURDATE() <5> if transfer date has been passed(means transfer has been done) then return futureUnitID otherwise return pastUnitID i used two separate query but don't know how to join those query?? for step <1 ans <2 SELECT unit_id FROM table_joining WHERE joining_date<=CURDATE() AND transfer_id IS NULL AND unit_id='u_3' for step<5 SELECT IF(effective_transfer_date <= CURDATE(),futureUnitId,pastUnitId) AS currentUnitID FROM table_transfer // here how do we select only those rows which have currentUnitID='u_3' ?? please guide me the process?? i m just confused with JOINS. i think using LEFT JOIN can return the data i need, or if we use subquery value to main query? but i m not getting how to implement ...please help me. Thanks for helping me alwayz

  Read the article

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >