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  • Hibernate Criteria: Perform JOIN in Subquery/DetachedCriteria

    - by Gilean
    I'm running into an issue with adding JOIN's to a subquery using DetachedCriteria. The code looks roughly like this: Criteria criteria = createCacheableCriteria(ProductLine.class, "productLine"); criteria.add(Expression.eq("productLine.active", "Y")); DetachedCriteria subCriteria = DetachedCriteria.forClass(Models.class, "model"); subCriteria.setProjection(Projections.rowCount()); subCriteria.createAlias("model.language", "modelLang"); criteria.add(Expression.eq("modelLang.language_code", "EN")); subCriteria.add(Restrictions.eqProperty("model.productLine.id","productLine.id")); criteria.add(Subqueries.lt(0, subCriteria)); But the logged SQL does not contain the JOIN in the subquery, but does include the alias which is throwing an error SELECT * FROM PRODUCT_LINES this_ WHERE this_.ACTIVE=? AND ? < (SELECT COUNT(*) AS y0_ FROM MODELS this0__ WHERE modelLang3_.LANGUAGE ='EN' AND this0__.PRODUCT_LINE_ID =this_.ID ) How can I add the joins to the DetachedCriteria? Hibernate version: 3.2.6.ga Hibernate core: 3.3.2.GA Hibernate annotations: 3.4.0.GA Hibernate commons-annotations: 3.3.0.ga Hibernate entitymanager: 3.4.0.GA Hibernate validator: 3.1.0.GA

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  • Select the latest record for each category linked available on an object

    - by Simpleton
    I have a tblMachineReports with the columns: Status(varchar),LogDate(datetime),Category(varchar), and MachineID(int). I want to retrieve the latest status update from each category for every machine, so in effect getting a snapshot of the latest statuses of all the machines unique to their MachineID. The table data would look like Category - Status - MachineID - LogDate cata - status1 - 001 - date1 cata - status2 - 002 - date2 catb - status3 - 001 - date2 catc - status2 - 002 - date4 cata - status3 - 001 - date5 catc - status1 - 001 - date6 catb - status2 - 001 - date7 cata - status2 - 002 - date8 catb - status2 - 002 - date9 catc - status2 - 001 - date10 Restated, I have multiple machines reporting on multiple statuses in this tblMachineReports. All the rows are created through inserts, so their will obviously be duplicate entries for machines as new statuses come in. None of the columns can be predicted, so I can't do any ='some hard coded string' comparisons in any part of the select statement. For the sample table I provided, the desired results would look like: Category - Status - MachineID - LogDate catc - status2 - 002 - date4 cata - status3 - 001 - date5 catb - status2 - 001 - date7 cata - status2 - 002 - date8 catb - status2 - 002 - date9 catc - status2 - 001 - date10 What would the select statement look like to achieve this, getting the latest status for each category on each machine, using MS SQL Server 2008? I have tried different combinations of subqueries combined with aggregate MAX(LogDates)'s, along with joins, group bys, distincts, and what-not, but have yet to find a working solution.

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  • NHibernate - joining on a subquery using ICriteria

    - by owensymes.mp
    I have a SQL query that I need to represent using NHibernate's ICriteria API. SELECT u.Id as Id, u.Login as Login, u.FirstName as FirstName, u.LastName as LastName, gm.UserGroupId_FK as UserGroupId, inner.Data1, inner.Data2, inner.Data3 FROM dbo.User u inner join dbo.GroupMember gm on u.Id = gm.UserAnchorId_FK left join ( SELECT di.UserAnchorId_FK, sum(di.Data1) as Data1, sum(di.Data2) as Data2, sum(di.Data3) as Data3 FROM dbo.DailyInfo di WHERE di.Date between '2009-04-01' and '2009-06-01' GROUP BY di.UserAnchorId_FK ) inner ON inner.UserAnchorId_FK = u.Id WHERE gm.UserGroupId_FK = 195 Attempts so far have included mapping 'User' and 'DailyInfo' classes (my entities) and making a DailyInfo object a property of the User object. However, how to map the foreign key relationship between them is still a mystery, ie <one-to-one></one-to-one> <one-to-many></one-to-many> <generator class="foreign"><param name="property">Id</param></generator> (!) Solutions on the web are generally to do with subqueries within a WHERE clause, however I need to left join on this subquery instead to ensure NULL values are returned for rows that do not join. I have the feeling that I should be using a Criteria for the outer query, then forming a 'join' with a DetachedCriteria to represent the subquery?

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  • What is the proper query to get all the children in a tree?

    - by Nathan Adams
    Lets say I have the following MySQL structure: CREATE TABLE `domains` ( `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT, `domain` CHAR(50) NOT NULL, `parent` INT(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=MYISAM AUTO_INCREMENT=10 DEFAULT CHARSET=latin1 insert into `domains`(`id`,`domain`,`parent`) values (1,'.com',0); insert into `domains`(`id`,`domain`,`parent`) values (2,'example.com',1); insert into `domains`(`id`,`domain`,`parent`) values (3,'sub1.example.com',2); insert into `domains`(`id`,`domain`,`parent`) values (4,'sub2.example.com',2); insert into `domains`(`id`,`domain`,`parent`) values (5,'s1.sub1.example.com',3); insert into `domains`(`id`,`domain`,`parent`) values (6,'s2.sub1.example.com',3); insert into `domains`(`id`,`domain`,`parent`) values (7,'sx1.s1.sub1.example.com',5); insert into `domains`(`id`,`domain`,`parent`) values (8,'sx2.s2.sub1.example.com',6); insert into `domains`(`id`,`domain`,`parent`) values (9,'x.sub2.example.com',4); In my mind that is enough to emulate a simple tree structure: .com | example / \ sub1 sub2 ect My problem is that give sub1.example.com I want to know all the children of sub1.example.com without using multiple queries in my code. I have tried joining the table to itself and tried to use subqueries, I can't think of anything that will reveal all the children. At work we are using MPTT to keep in hierarchal order a list of domains/subdomains however, I feel that there is an easier way to do it. I did some digging and someone did something similar but they required the use of a function in MySQL. I don't think for something simple like this we would need a whole function. Maybe I am just dumb and not seeing some sort of obvious solution. Also, feel free to alter the structure.

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  • django: can't adapt error when importing data from postgres database

    - by Oleg Tarasenko
    Hi, I'm having strange error with installing fixture from dumped data. I am using psycopg2, and django1.1.1 silver:probsbox oleg$ python manage.py loaddata /Users/oleg/probs.json Installing json fixture '/Users/oleg/probs' from '/Users/oleg/probs'. Problem installing fixture '/Users/oleg/probs.json': Traceback (most recent call last): File "/opt/local/lib/python2.5/site-packages/django/core/management/commands/loaddata.py", line 153, in handle obj.save() File "/opt/local/lib/python2.5/site-packages/django/core/serializers/base.py", line 163, in save models.Model.save_base(self.object, raw=True) File "/opt/local/lib/python2.5/site-packages/django/db/models/base.py", line 495, in save_base result = manager._insert(values, return_id=update_pk) File "/opt/local/lib/python2.5/site-packages/django/db/models/manager.py", line 177, in _insert return insert_query(self.model, values, **kwargs) File "/opt/local/lib/python2.5/site-packages/django/db/models/query.py", line 1087, in insert_query return query.execute_sql(return_id) File "/opt/local/lib/python2.5/site-packages/django/db/models/sql/subqueries.py", line 320, in execute_sql cursor = super(InsertQuery, self).execute_sql(None) File "/opt/local/lib/python2.5/site-packages/django/db/models/sql/query.py", line 2369, in execute_sql cursor.execute(sql, params) File "/opt/local/lib/python2.5/site-packages/django/db/backends/util.py", line 19, in execute return self.cursor.execute(sql, params) ProgrammingError: can't adapt First I've checked similar issues on internet. This one seemed to be very related: http://code.djangoproject.com/ticket/5996, as my data has many non ASCII symbols But actually I've checked my django installation and it's ok there Could you advice what is wrong

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  • Beginner SQL question: querying gold and silver tag badges in Stack Exchange Data Explorer

    - by polygenelubricants
    I'm using the Stack Exchange Data Explorer to learn SQL, but I think the fundamentals of the question is applicable to other databases. I'm trying to query the Badges table, which according to Stexdex (that's what I'm going to call it from now on) has the following schema: Badges Id UserId Name Date This works well for badges like [Epic] and [Legendary] which have unique names, but the silver and gold tag-specific badges seems to be mixed in together by having the same exact name. Here's an example query I wrote for [mysql] tag: SELECT UserId as [User Link], Date FROM Badges Where Name = 'mysql' Order By Date ASC The (slightly annotated) output is: as seen on stexdex: User Link Date --------------- ------------------- // all for silver except where noted Bill Karwin 2009-02-20 11:00:25 Quassnoi 2009-06-01 10:00:16 Greg 2009-10-22 10:00:25 Quassnoi 2009-10-31 10:00:24 // for gold Bill Karwin 2009-11-23 11:00:30 // for gold cletus 2010-01-01 11:00:23 OMG Ponies 2010-01-03 11:00:48 Pascal MARTIN 2010-02-17 11:00:29 Mark Byers 2010-04-07 10:00:35 Daniel Vassallo 2010-05-14 10:00:38 This is consistent with the current list of silver and gold earners at the moment of this writing, but to speak in more timeless terms, as of the end of May 2010 only 2 users have earned the gold [mysql] tag: Quassnoi and Bill Karwin, as evidenced in the above result by their names being the only ones that appear twice. So this is the way I understand it: The first time an Id appears (in chronological order) is for the silver badge The second time is for the gold Now, the above result mixes the silver and gold entries together. My questions are: Is this a typical design, or are there much friendlier schema/normalization/whatever you call it? In the current design, how would you query the silver and gold badges separately? GROUP BY Id and picking the min/max or first/second by the Date somehow? How can you write a query that lists all the silver badges first then all the gold badges next? Imagine also that the "real" query may be more complicated, i.e. not just listing by date. How would you write it so that it doesn't have too many repetition between the silver and gold subqueries? Is it perhaps more typical to do two totally separate queries instead? What is this idiom called? A row "partitioning" query to put them into "buckets" or something?

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  • how do i filter my lucene search results?

    - by Andrew Bullock
    Say my requirement is "search for all users by name, who are over 18" If i were using SQL, i might write something like: Select * from [Users] Where ([firstname] like '%' + @searchTerm + '%' OR [lastname] like '%' + @searchTerm + '%') AND [age] >= 18 However, im having difficulty translating this into lucene.net. This is what i have so far: var parser = new MultiFieldQueryParser({ "firstname", "lastname"}, new StandardAnalyser()); var luceneQuery = parser.Parse(searchterm) var query = FullTextSession.CreateFullTextQuery(luceneQuery, typeof(User)); var results = query.List<User>(); How do i add in the "where age = 18" bit? I've heard about .SetFilter(), but this only accepts LuceneQueries, and not IQueries. If SetFilter is the right thing to use, how do I make the appropriate filter? If not, what do I use and how do i do it? Thanks! P.S. This is a vastly simplified version of what I'm trying to do for clarity, my WHERE clause is actually a lot more complicated than shown here. In reality i need to check if ids exist in subqueries and check a number of unindexed properties. Any solutions given need to support this. Thanks

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  • Criteria API - How to get records based on collection count?

    - by Cosmo
    Hello Guys! I have a Question class in ActiveRecord with following fields: [ActiveRecord("`Question`")] public class Question : ObcykaniDb<Question> { private long id; private IList<Question> relatedQuestions; [PrimaryKey("`Id`")] private long Id { get { return this.id; } set { this.id = value; } } [HasAndBelongsToMany(typeof(Question), ColumnRef = "ChildId", ColumnKey = "ParentId", Table = "RelatedQuestion")] private IList<Question> RelatedQuestions { get { return this.relatedQuestions; } set { this.relatedQuestions = value; } } } How do I write a DetachedCriteria query to get all Questions that have at least 5 related questions (count) in the RelatedQuestions collection? For now this gives me strange results: DetachedCriteria dCriteria = DetachedCriteria.For<Question>() .CreateCriteria("RelatedQuestions") .SetProjection(Projections.Count("Id")) .Add(Restrictions.EqProperty(Projections.Id(), "alias.Id")); DetachedCriteria dc = DetachedCriteria.For<Question>("alias").Add(Subqueries.Le(5, dCriteria)); IList<Question> results = Question.FindAll(dc); Any ideas what I'm doing wrong?

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  • Best way to randomly select rows *per* column in SQL Server

    - by LesterDove
    A search of SO yields many results describing how to select random rows of data from a database table. My requirement is a bit different, though, in that I'd like to select individual columns from across random rows in the most efficient/random/interesting way possible. To better illustrate: I have a large Customers table, and from that I'd like to generate a bunch of fictitious demo Customer records that aren't real people. I'm thinking of just querying randomly from the Customers table, and then randomly pairing FirstNames with LastNames, Address, City, State, etc. So if this is my real Customer data (simplified): FirstName LastName State ========================== Sally Simpson SD Will Warren WI Mike Malone MN Kelly Kline KS Then I'd generate several records that look like this: FirstName LastName State ========================== Sally Warren MN Kelly Malone SD Etc. My initial approach works, but it lacks the elegance that I'm hoping the final answer will provide. (I'm particularly unhappy with the repetitiveness of the subqueries, and the fact that this solution requires a known/fixed number of fields and therefore isn't reusable.) SELECT FirstName = (SELECT TOP 1 FirstName FROM Customer ORDER BY newid()), LastName= (SELECT TOP 1 LastNameFROM Customer ORDER BY newid()), State = (SELECT TOP 1 State FROM Customer ORDER BY newid()) Thanks!

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  • How to nest joins with CakePHP?

    - by Daren Thomas
    I'm trying to behave. So, instead of using following SQL syntax: select * from tableA INNER JOIN tableB on tableA.id = tableB.tableA_id LEFT OUTER JOIN ( tableC INNER JOIN tableD on tableC.tableD_id = tableD.id) on tableC.tableA_id = tableA.id I'd like to use the CakePHP model->find(). This will let me use the Paginator too, since that will not work with custom SQL queries as far as I understand (unless you hardcode one single pagination query to the model which seems a little inflexible to me). What I've tried so far: /* inside tableA_controller.php, inside an action, e.g. "view" */ $this->paginate['recursive'] = -1; # suppress model associations for now $this->paginate['joins'] = array( array( 'table' => 'tableB', 'alias' => 'TableB', 'type' => 'inner', 'conditions' => 'TableB.tableA_id = TableA.id', ), array( 'table' => 'tableC', 'alias' => 'TableC', 'type' => 'left', 'conditions' => 'TableC.tableA_id = TableA.id', 'joins' = array( # this would be the obvious way to do it, but doesn't work array( 'table' => 'tableD', 'alias' => 'TableD', 'type' => 'inner', 'conditions' => 'TableC.tableD_id = TableD.id' ) ) ) ) That is, nesting the joins into the structure. But that doesn't work (CakePHP just ignores the nested 'joins' element which was kind of what I expected, but sad. I have seen hints in comments on how to do subqueries (in the where clause) using a statement builder. Can a similar trick be used here?

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  • ways to avoid global temp tables in oracle

    - by Omnipresent
    We just converted our sql server stored procedures to oracle procedures. Sql Server SP's were highly dependent on session tables (INSERT INTO #table1...) these tables got converted as global temporary tables in oracle. We ended up with aroun 500 GTT's for our 400 SP's Now we are finding out that working with GTT's in oracle is considered a last option because of performance and other issues. what other alternatives are there? Collections? Cursors? Our typical use of GTT's is like so: Insert into GTT INSERT INTO some_gtt_1 (column_a, column_b, column_c) (SELECT someA, someB, someC FROM TABLE_A WHERE condition_1 = 'YN756' AND type_cd = 'P' AND TO_NUMBER(TO_CHAR(m_date, 'MM')) = '12' AND (lname LIKE (v_LnameUpper || '%') OR lname LIKE (v_searchLnameLower || '%')) AND (e_flag = 'Y' OR it_flag = 'Y' OR fit_flag = 'Y')); Update the GTT UPDATE some_gtt_1 a SET column_a = (SELECT b.data_a FROM some_table_b b WHERE a.column_b = b.data_b AND a.column_c = 'C') WHERE column_a IS NULL OR column_a = ' '; and later on get the data out of the GTT. These are just sample queries, in actuality the queries are really complext with lot of joins and subqueries. I have a three part question: Can someone show how to transform the above sample queries to collections and/or cursors? Since with GTT's you can work natively with SQL...why go away from the GTTs? are they really that bad. What should be the guidelines on When to use and When to avoid GTT's

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  • Rails Active Record Mysql find query HAVING clause

    - by meetraghu28
    Is there a way to use the HAVING clause in some other way without using group by. I am using rails and following is a sample sccenario of the problem that i am facing. In rails you can use the Model.find(:all,:select,conditions,:group) function to get data. In this query i can specify a having clause in the :group param. But what if i dont have a group by clause but want to have a having clause in the result set. Ex: Lets take a query select sum(x) as a,b,c from y where "some_conditions" group by b,c; This query has a sum() aggregation on one of the fields. No if there is nothing to aggregate then my result should be an empty set. But mysql return a NULL row. So this problem can be solved by using select sum(x) as a,b from y where "some_conditions" group by b having a NOT NULL; but what happens in case i dont have a group by clause?? a query like below select sum(x) as a,b from y where "some_conditions"; so how to specify that sum(x) should not be NULL? Any solution that would return an empty set in this case instead of a NULL row will help and also that solution should be doable in rails. We can use subqueries to get this condition working with sumthin like this select * from ((select sum(x) as b FROM y where "some_condition") as subq) where subq.b is not null; but is there a better way to do this thru sql/rails ??

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  • Best way to randomly select columns from random rows of SQL results.

    - by LesterDove
    A search of SO yields many results describing how to select random rows of data from a database table. My requirement is a bit different, though, in that I'd like to select individual columns from across random rows in the most efficient/random/interesting way possible. To better illustrate: I have a large Customers table, and from that I'd like to generate a bunch of fictitious demo Customer records that aren't real people. I'm thinking of just querying randomly from the Customers table, and then randomly pairing FirstNames with LastNames, Address, City, State, etc. So if this is my real Customer data (simplified): FirstName LastName State ========================== Sally Simpson SD Will Warren WI Mike Malone MN Kelly Kline KS Then I'd generate several records that look like this: FirstName LastName State ========================== Sally Warren MN Kelly Malone SD Etc. My initial approach works, but it lacks the elegance that I'm hoping the final answer will provide. (I'm particularly unhappy with the repetitiveness of the subqueries, and the fact that this solution requires a known/fixed number of fields and therefore isn't reusable.) SELECT FirstName = (SELECT TOP 1 FirstName FROM Customer ORDER BY newid()), LastName= (SELECT TOP 1 LastNameFROM Customer ORDER BY newid()), State = (SELECT TOP 1 State FROM Customer ORDER BY newid()) Thanks!

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  • Subquery max sequence number

    - by Andy Levesque
    I'm hesitant to ask because I'm sure it's out there, but I just can't seem to come up with the keywords to find the answer. I'm stepping outside my boundaries by starting with subqueries (normally an Access user). I have a query that has TECH_ID, SEQ_NBR, and PELL_FT_AWD_AMT SELECT ISRS_V_NEED_ANAL_RESULT_PARENT.TECH_ID, ISRS_V_NEED_ANAL_RESULT_PARENT.AWD_YR, ISRS_V_NEED_ANAL_RESULT_PARENT.PELL_FT_AWD_AMT, ISRS_V_NEED_ANAL_RESULT_PARENT.SEQ_NBR FROM ISRS_V_NEED_ANAL_RESULT_PARENT GROUP BY ISRS_V_NEED_ANAL_RESULT_PARENT.TECH_ID, ISRS_V_NEED_ANAL_RESULT_PARENT.AWD_YR, ISRS_V_NEED_ANAL_RESULT_PARENT.PELL_FT_AWD_AMT, ISRS_V_NEED_ANAL_RESULT_PARENT.SEQ_NBR HAVING (((ISRS_V_NEED_ANAL_RESULT_PARENT.AWD_YR)="2013")) ORDER BY ISRS_V_NEED_ANAL_RESULT_PARENT.TECH_ID; What I want to return is add a subquery that selects only the max SEQ_NUM for each record, but I can't seem to get the syntax right. In the past I would cheat and have a separate query that first gave me the TECH_ID and max SEQ_NUM, and then have a second query that use the original table and the first query in a join to get the rest. How can I do this in one query? Example: TECH_ID SEQ_NUM PELL 1 1 4000 1 2 4000 1 3 5000 Using just the max of the sequence number still returns: 1; 2; 4000 and 1; 3; 5000 when I'm only wanting the latter.

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  • What's the most efficient query?

    - by Aaron Carlino
    I have a table named Projects that has the following relationships: has many Contributions has many Payments In my result set, I need the following aggregate values: Number of unique contributors (DonorID on the Contribution table) Total contributed (SUM of Amount on Contribution table) Total paid (SUM of PaymentAmount on Payment table) Because there are so many aggregate functions and multiple joins, it gets messy do use standard aggregate functions the the GROUP BY clause. I also need the ability to sort and filter these fields. So I've come up with two options: Using subqueries: SELECT Project.ID AS PROJECT_ID, (SELECT SUM(PaymentAmount) FROM Payment WHERE ProjectID = PROJECT_ID) AS TotalPaidBack, (SELECT COUNT(DISTINCT DonorID) FROM Contribution WHERE RecipientID = PROJECT_ID) AS ContributorCount, (SELECT SUM(Amount) FROM Contribution WHERE RecipientID = PROJECT_ID) AS TotalReceived FROM Project; Using a temporary table: DROP TABLE IF EXISTS Project_Temp; CREATE TEMPORARY TABLE Project_Temp (project_id INT NOT NULL, total_payments INT, total_donors INT, total_received INT, PRIMARY KEY(project_id)) ENGINE=MEMORY; INSERT INTO Project_Temp (project_id,total_payments) SELECT `Project`.ID, IFNULL(SUM(PaymentAmount),0) FROM `Project` LEFT JOIN `Payment` ON ProjectID = `Project`.ID GROUP BY 1; INSERT INTO Project_Temp (project_id,total_donors,total_received) SELECT `Project`.ID, IFNULL(COUNT(DISTINCT DonorID),0), IFNULL(SUM(Amount),0) FROM `Project` LEFT JOIN `Contribution` ON RecipientID = `Project`.ID GROUP BY 1 ON DUPLICATE KEY UPDATE total_donors = VALUES(total_donors), total_received = VALUES(total_received); SELECT * FROM Project_Temp; Tests for both are pretty comparable, in the 0.7 - 0.8 seconds range with 1,000 rows. But I'm really concerned about scalability, and I don't want to have to re-engineer everything as my tables grow. What's the best approach?

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  • Adding one subquery makes query a little slower, adding another makes it way slower

    - by Jason Swett
    This is fast: select ba.name, penamt.value penamt, #address_line4.value address_line4 from account a join customer c on a.customer_id = c.id join branch br on a.branch_id = br.id join bank ba on br.bank_id = ba.id join account_address aa on aa.account_id = a.id join address ad on aa.address_id = ad.id join state s on ad.state_id = s.id join import i on a.import_id = i.id join import_bundle ib on i.import_bundle_id = ib.id join (select * from unused where heading_label = 'PENAMT') penamt ON penamt.account_id = a.id #join (select * from unused where heading_label = 'Address Line 4') address_line4 ON address_line4.account_id = a.id where i.active=1 And this is fast: select ba.name, #penamt.value penamt, address_line4.value address_line4 from account a join customer c on a.customer_id = c.id join branch br on a.branch_id = br.id join bank ba on br.bank_id = ba.id join account_address aa on aa.account_id = a.id join address ad on aa.address_id = ad.id join state s on ad.state_id = s.id join import i on a.import_id = i.id join import_bundle ib on i.import_bundle_id = ib.id #join (select * from unused where heading_label = 'PENAMT') penamt ON penamt.account_id = a.id join (select * from unused where heading_label = 'Address Line 4') address_line4 ON address_line4.account_id = a.id where i.active=1 But this is slow: select ba.name, penamt.value penamt, address_line4.value address_line4 from account a join customer c on a.customer_id = c.id join branch br on a.branch_id = br.id join bank ba on br.bank_id = ba.id join account_address aa on aa.account_id = a.id join address ad on aa.address_id = ad.id join state s on ad.state_id = s.id join import i on a.import_id = i.id join import_bundle ib on i.import_bundle_id = ib.id join (select * from unused where heading_label = 'PENAMT') penamt ON penamt.account_id = a.id join (select * from unused where heading_label = 'Address Line 4') address_line4 ON address_line4.account_id = a.id where i.active=1 Why is it fast when I include just one of the two subqueries but slow when I include both? I would think it should be twice as slow when I include both, but it takes a really long time. On on MySQL.

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  • Nhibernate - stuck with detached criteria (asp.net mvc 1 with nhibernate 2) c#

    - by Jen
    OK so I can't find a good example of this so I can better understand how to use detached criteria (assuming that's what I want to use in the first place). I have 2 tables. Placement and PlacementSupervisor My PlacementSupervisor table has a FK of PlacementID which relates to Placement.PlacementID - though my nhibernate model class has PlacementSupervisor . Placement (rather than specifically specifying a property of placement ID - not sure if this is important). What I am trying to do is - if values are passed through for the supervisor ID I want to restrict placements with that supervisor id. Have tried: ICriteria query = m_PlacementRepository.QueryAlias("p") .... if (criteria.SupervisorId > 0 && !string.IsNullOrEmpty(criteria.SupervisorTypeId)) { DetachedCriteria entityQuery = DetachedCriteria.For<PlacementSupervisor>("sup") .Add(Restrictions.And( Restrictions.Eq("sup.supervisorId", criteria.SupervisorId), Restrictions.Eq("sup.supervisorTypeId", criteria.SupervisorTypeId) )) .SetProjection(Projections.ProjectionList() .AddPropertyAlias("Placement.PlacementId", "PlacementId") ); query.Add(Subqueries.PropertyIn("p.PlacementId", entityQuery)); } Which just gives me the error: Could not find a matching criteria info provider to: (sup.supervisorId = 5 and sup.supervisorTypeId = U) Firstly supervisorTypeId is a string. Secondly I don't understand how to achieve what I'm trying to do so have just been trying various combinations of projections, and property aliases and subquery options..as I don't get how I'm supposed to join to another table/entity when the FK key sits in the second table. Can someone point me in the right direction. It seems like such an easy thing to do from a data perspective that hopefully I'm just missing something obvious!!

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  • confusion about using types instead of gtts in oracle

    - by Omnipresent
    I am trying to convert queries like below to types so that I won't have to use GTT: insert into my_gtt_table_1 (house, lname, fname, MI, fullname, dob) (select house, lname, fname, MI, fullname, dob from (select 'REG' house, mbr_last_name lname, mbr_first_name fname, mbr_mi MI, mbr_first_name || mbr_mi || mbr_last_name fullname, mbr_dob dob from table_1 a, table_b where a.head = b.head and mbr_number = '01' and mbr_last_name = v_last_name) c above is just a sample but complex queries are bigger than this. the above is inside a stored procedure. So to avoid the gtt (my_gtt_table_1). I did the following: create or replace type lname_row as object ( house varchar2(30) lname varchar2(30), fname varchar2(30), MI char(1), fullname VARCHAR2(63), dob DATE ) create or replace type lname_exact as table of lname_row Now in the SP: type lname_exact is table of <what_table_should_i_put_here>%rowtype; tab_a_recs lname_exact; In the above I am not sure what table to put as my query has nested subqueries. query in the SP: (I am trying this for sample purpose to see if it works) select lname_row('', '', '', '', '', '', sysdate) bulk collect into tab_a_recs from table_1; I am getting errors like : ORA-00913: too many values I am really confused and stuck with this :(

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  • Creating a Linq->HQL provider

    - by Mike Q
    Hi all, I have a client application that connects to a server. The server uses hibernate for persistence and querying so it has a set of annotated hibernate objects for persistence. The client sends HQL queries to the server and gets responses back. The client has an auto-generated set of objects that match the server hibernate objects for query results and basic persistence. I would like to support using Linq to query as well as Hql as it makes the queries typesafe and quicker to build (no more typos in HQL string queries). I've looked around at the following but I can't see how to get them to fit with what I have. NHibernate's Linq provider - requires using NHibernate ISession and ISessionFactory, which I don't have LinqExtender - requires a lot of annotations on the objects and extending a base type, too invasive What I really want is something that will generate give me a nice easy to process structure to build the HQL queries from. I've read most of a 15 page article written by one of the C# developers on how to create custom providers and it's pretty fraught, mainly because of the complexity of the expression tree. Can anyone suggest an approach for implementing Linq - HQL translation? Perhaps a library that will the cleanup of the expression tree into something more SQL/HQLish. I would like to support select/from/where/group by/order by/joins. Not too worried about subqueries.

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  • How Best to Replace PL/SQL with C#?

    - by Mike
    Hi, I write a lot of one-off Oracle SQL queries/reports (in Toad), and sometimes they can get complex, involving lots of unions, joins, and subqueries, and/or requiring dynamic SQL, and/or procedural logic. PL/SQL is custom made for handling these situations, but as a language it does not compare to C#, and even if it did, it's tooling does not, and if even that did, forcing yet another language on the team is something to be avoided whenever possible. Experience has shown me that using SQL for the set based processing, coupled with C# for the procedural processing, is a powerful combination indeed, and far more readable, maintainable and enhanceable than PL/SQL. So, we end up with a number of small C# programs which typically would construct a SQL query string piece by piece and/or run several queries and process them as needed. This kind of code could easily be a disaster, but a good developer can make this work out quite well, and end up with very readable code. So, I don't think it's a bad way to code for smaller DB focused projects. My main question is, how best to create and package all these little C# programs that run ad hoc queries and reports against the database? Right now I create little report objects in a DLL, developed and tested with NUnit, but then I continue to use NUnit as the GUI to select and run them. NUnit just happens to provide a nice GUI for this kind of thing, even after testing has been completed. I'm also interested in suggestions for reporting apps generally. I feel like there is a missing piece or product. The perfect tool would allow writing and running C# inside of Toad, or SQL inside of Visual Studio, along with simple reporting facilities. All ideas will be appreciated, but let's make the assumption that PL/SQL is not the solution.

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  • In mysql, is "explain ..." always safe?

    - by tye
    If I allow a group of users to submit "explain $whatever" to mysql (via Perl's DBI using DBD::mysql), is there anything that a user could put into $whatever that would make any database changes, leak non-trivial information, or even cause significant database load? If so, how? I know that via "explain $whatever" one can figure out what tables / columns exist (you have to guess names, though) and roughly how many records are in a table or how many records have a particular value for an indexed field. I don't expect one to be able to get any information about the contents of unindexed fields. DBD::mysql should not allow multiple statements so I don't expect it to be possible to run any query (just explain one query). Even subqueries should not be executed, just explained. But I'm not a mysql expert and there are surely features of mysql that I'm not even aware of. In trying to come up with a query plan, might the optimizer actual execute an expression in order to come up with the value that an indexed field is going to be compared against? explain select * from atable where class = somefunction(...) where atable.class is indexed and not unique and class='unused' would find no records but class='common' would find a million records. Might 'explain' evaluate somefunction(...)? And then could somefunction(...) be written such that it modifies data?

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  • How Best to Replace Ugly Queries and Dynamic PL/SQL with C#?

    - by Mike
    Hi, I write a lot of one-off Oracle SQL queries (in Toad), and sometimes they can get complex, involving lots of unions, joins, and subqueries, and sometimes requiring dynamic SQL. That is, sometimes SQL queries require set based processing along with significant procedural processing. This is what PL/SQL is custom made for, but as a language it does not begin to compare to C#. Now and then I convert a PL/SQL procedure to C#, and am always amazed at how much cleaner and easier to both read and write the C# version is. The C# program might for example construct a SQL query string piece by piece and/or run several queries and process them as needed. The C# version is usually much faster as well, which must mean that I'm not very good at PL/SQL either. I do not currently have access to LINQ. My question is, how best to package all these little C# programs, which are really just mini reports, that is, replacements for ugly SQL queries? Right now I'm actually using NUnit to hold them, and calling each report a [Test], even though they aren't really tests. NUnit just happens to provide a convenient packaging framework.

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  • Get the first and last posts in a thread

    - by Grampa
    I am trying to code a forum website and I want to display a list of threads. Each thread should be accompanied by info about the first post (the "head" of the thread) as well as the last. My current database structure is the following: threads table: id - int, PK, not NULL, auto-increment name - varchar(255) posts table: id - int, PK, not NULL, auto-increment thread_id - FK for threads The tables have other fields as well, but they are not relevant for the query. I am interested in querying threads and somehow JOINing with posts so that I obtain both the first and last post for each thread in a single query (with no subqueries). So far I am able to do it using multiple queries, and I have defined the first post as being: SELECT * FROM threads t LEFT JOIN posts p ON t.id = p.thread_id ORDER BY p.id LIMIT 0, 1 The last post is pretty much the same except for ORDER BY id DESC. Now, I could select multiple threads with their first or last posts, by doing: SELECT * FROM threads t LEFT JOIN posts p ON t.id = p.thread_id ORDER BY p.id GROUP BY t.id But of course I can't get both at once, since I would need to sort both ASC and DESC at the same time. What is the solution here? Is it even possible to use a single query? Is there any way I could change the structure of my tables to facilitate this? If this is not doable, then what tips could you give me to improve the query performance in this particular situation?

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  • Complex sorting on MySQL database

    - by ChrisR
    I'm facing the following situation. We've got an CMS with an entity with translations. These translations are stored in a different table with a one-to-many relationship. For example newsarticles and newsarticle_translations. The amount of available languages is dynamically determined by the same CMS. When entering a new newsarticle the editor is required to enter at least one translation, which one of the available languages he chooses is up to him. In the newsarticle overview in our CMS we would like to show a column with the (translated) article title, but since none of the languages are mandatory (one of them is mandatory but i don't know which one) i don't really know how to construct my mysql query to select a title for each newsarticle, regardless of the entered language. And to make it all a little harder, our manager asked for the possibilty to also be able to sort on title, so fetching the translations in a separate query is ruled out as far as i know. Anyone has an idea on how to solve this in the most efficient way? Here are my table schema's it it might help > desc news; +-----------------+----------------+------+-----+-------------------+----------------+ | Field | Type | Null | Key | Default | Extra | +-----------------+----------------+------+-----+-------------------+----------------+ | id | int(10) | NO | PRI | NULL | auto_increment | | category_id | int(1) | YES | | NULL | | | created | timestamp | NO | | CURRENT_TIMESTAMP | | | user_id | int(10) | YES | | NULL | | +-----------------+----------------+------+-----+-------------------+----------------+ > desc news_translations; +-----------------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-----------------+------------------+------+-----+---------+----------------+ | id | int(10) unsigned | NO | PRI | NULL | auto_increment | | enabled | tinyint(1) | NO | | 0 | | | news_id | int(1) unsigned | NO | | NULL | | | title | varchar(255) | NO | | | | | summary | text | YES | | NULL | | | body | text | NO | | NULL | | | language | varchar(2) | NO | | NULL | | +-----------------+------------------+------+-----+---------+----------------+ PS: i've though about subqueries and coalesce() solutions but those seem rather dirty tricks, wondering if something better is know that i'm not thinking of?

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  • Rails 3 fields_for agressive loading?

    - by Seth
    Hi all, I'm trying to optimize (limit) queries in a view. I am using the fields_for function. I need to reference various properties of the object, such as username for display purposes. However, this is a rel table, so I need to join with my users table. The result is N sub-queries, 1 for each field in fields_for. It's difficult to explain, but I think you'll understand what I'm asking if I paste my code: <%= form_for @election do |f| %> <%= f.fields_for :voters do |voter| %> <%= voter.hidden_field :id %> <%= voter.object.user.preferred_name %> <% end %> <% end %> I have like 10,000 users, and many times each election will include all 10,000 users. That's 10,000 subqueries every time this view is loaded. I want fields_for to JOIN on users. Is this possible? I'd like to do something like: ... <%= f.fields_for :voters, :joins => :users do |voter| %> ... <% end %> ... But that, of course, doesn't work :(

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