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  • How do I get this sql to linq? Multiple groups

    - by Dwight T
    For a db person, LINQ can be frustrating. I need to convert the following SQL into Linq. SELECT COUNT(o.objectiveid), COUNT(distinct r.ReviewId), l.Abbreviation FROM Objective o JOIN Review r on r.ReviewId = o.ReviewId and r.ReviewPeriodId = 3 and r.IsDeleted = 0 JOIN Position p on p.PositionId = r.EmployeePositionId and p.DivisionId = 2 JOIN Location l on l.LocationId = p.LocationId GROUP BY l.Abbreviation The group by nested example might be the way I have to go, but not sure. Doing one group by I have used the following code: var query = from rev in db.Reviews .Where(r => r.IsDeleted == false && r.ReviewPeriodId == reviewPeriodId) from obj in db.Objectives .Where(o => o.ReviewId == rev.ReviewId && o.IsDeleted == false) from pos in db.Positions .Where(p => rev.EmployeePositionId == p.PositionId && p.IsDeleted == false && p.DivisionId == divisionId ) from loc in db.Locations .Where(l => pos.LocationId == l.LocationId) group loc by loc.Abbreviation into locgroup select new ReportResults { KeyId = 0, Description = locgroup.Key, Count = locgroup.Count() }; return query.ToList(); What is the correct way? Thanks

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  • Improve speed of a JOIN in MySQL

    - by ran2
    Dear all, I know there a similar threads around, but this is really the first time I realize that query speed might affect me - so it´s not that easy for me to really make the transfer from other folks problems. That being said I have using the following query successfully with smaller data, but if I use it on what are mildly large tables (about 120,000 records). I am waiting for hours. INSERT INTO anothertable (id,someint1,someint1,somevarchar1,somevarchar1) SELECT DISTINCT md.id,md.someint1,md.someint1,md.somevarchar1,pd.somevarchar1 from table1 AS md JOIN table2 AS pd ON (md.id = pd.id); Tables 1 and 2 contain about 120,000 records. The query has been running for almost 2 hours right now. Is this normal? Do I just have to wait. I really have no idea, but I am pretty sure that one could do it better since it´s my very first try. I read about indexing, but dont know yet what to index in my case? Thanks for any suggestions - feel free to point my to the very beginners guides ! best matt

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  • How to replace pairs of strings in two files to identical IDs?

    - by Péter Török
    Sorry if the title is not very intelligible, I couldn't come up with anything better. Hopefully my explanation is clear enough: I have a pair of rather large log files with very similar content, except that some strings are different between the two. A couple of examples: UnifiedClassLoader3@19518cc | UnifiedClassLoader3@d0357a JBossRMIClassLoader@13c2d7f | JBossRMIClassLoader@191777e That is, wherever the first file contains UnifiedClassLoader3@19518cc, the second contains UnifiedClassLoader3@d0357a, and so on. [Update] There are about 40 distinct pairs of such identifiers.[/Update] I want to replace these with identical IDs so that I can spot the really important differences between the two files. I.e. I want to replace all occurrences of both UnifiedClassLoader3@19518cc in file1 and UnifiedClassLoader3@d0357a in file2 with UnifiedClassLoader3@1; all occurrences of both JBossRMIClassLoader@13c2d7f in file1 and JBossRMIClassLoader@191777e in file2 with JBossRMIClassLoader@2 etc. Using the Cygwin shell, so far I managed to list all different identifiers occurring in one of the files with grep -o -e 'ClassLoader[0-9]*@[0-9a-f][0-9a-f]*' file1.log | sort | uniq However, now the original order is lost, so I don't know which is the pair of which ID in the other file. With grep -n I can get the line number, so the sort would preserve the order of appearance, but then I can't weed out the duplicate occurrences. Unfortunately grep can not print only the first match of a pattern. I figured I could save the list of identifiers produced by the above command into a file, then iterate over the patterns in the file with grep -n | head -n 1, concatenate the results and sort them again. The result would be something like 2 ClassLoader3@19518cc 137 ClassLoader@13c2d7f 563 ClassLoader3@1267649 ... Then I could (either manually or with sed itself) massage this into a sed command like sed -e 's/ClassLoader3@19518cc/ClassLoader3@2/g' -e 's/ClassLoader@13c2d7f/ClassLoader@137/g' -e 's/ClassLoader3@1267649/ClassLoader3@563/g' file1.log > file1_processed.log and similarly for file2. However, before I start, I would like to verify that my plan is the simplest possible working solution to this. Is there any flaw in this approach? Is there a simpler way?

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  • SQL: Order randomly when inserting objects to a table

    - by Ekaterina
    I have an UDF that selects top 6 objects from a table (with a union - code below) and inserts it into another table. (btw SQL 2005) So I paste the UDF below and what the code does is: selects objects for a specific city and add a level to those (from table Europe) union that selection with a selection from the same table for objects that are from the same country and add a level to those From the union, selection is made to get top 6 objects, order by level, so the objects from the same city will be first, and if there aren't any available, then objects from the same country will be returned from the selection. And my problem is, that I want to make a random selection to get random objects from table Europe, but because I insert the result of my selection into a table, I can't use order by newid() or rand() function because they are time-dependent, so I get the following errors: Invalid use of side-effecting or time-dependent operator in 'newid' within a function. Invalid use of side-effecting or time-dependent operator in 'rand' within a function. UDF: ALTER FUNCTION [dbo].[Objects] (@id uniqueidentifier) RETURNS @objects TABLE ( ObjectId uniqueidentifier NOT NULL, InternalId uniqueidentifier NOT NULL ) AS BEGIN declare @city varchar(50) declare @country int select @city = city, @country = country from Europe where internalId = @id insert @objects select @id, internalId from ( select distinct top 6 [level], internalId from ( select top 6 1 as [level], internalId from Europe N4 where N4.city = @city and N4.internalId != @id union select top 6 2 as [level], internalId from Europe N5 where N5.countryId = @country and N5.internalId != @id ) as selection_1 order by [level] ) as selection_2 return END If you have fresh ideas, please share them with me. (Just please, don't suggest to order by newid() or to add a column rand() with seed DateTime (by ms or sthg), because that won't work.)

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  • Fast, easy, and secure method to perform DB actions with GET

    - by rob - not a robber
    Hey All, Sort of a methods/best practices question here that I am sure has been addressed, yet I can't find a solution based on the vague search terms I enter. I know starting off the question with "Fast and easy" will probably draw out a few sighs, so my apologies. Here is the deal. I have a logged in area where an ADMIN can do a whole host of POST operations to input data relating to their profile. The way I have data structured is pretty distinct and well segmented in most tables as it relates to the ID of the admin. Now, I have a table where I dump one type of data into and differentiate this data by assigning the ADMIN's unique ID to each record. In other words, all ADMINs have this one type of data writing to this table. I just differentiate by the ADMIN ID with each record. I was planning on letting the ADMIN remove these records by clicking on a link with a query string - obviously using GET. Obviously, the query structure is in the link so any logged in admin could then exploit the URL and delete a competitor's records. Is the only way to safely do this through POST or should I pass through the session info that includes password and validate it against the ADMIN ID that is requesting the delete? This is obviously much more work for me. As they said in the auto repair biz I used to work in... there are 3 ways to do a job: Fast, Good, and Cheap. You can only have two at a time. Fast and cheap will not be good. Good and cheap will not have fast turnaround. Fast and good will NOT be cheap. haha I guess that applies here... can never have Fast, Easy and Secure all at once ;) Thanks in advance...

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  • Performance of VIEW vs. SQL statement

    - by Matt W.
    I have a query that goes something like the following: select <field list> from <table list> where <join conditions> and <condition list> and PrimaryKey in (select PrimaryKey from <table list> where <join list> and <condition list>) and PrimaryKey not in (select PrimaryKey from <table list> where <join list> and <condition list>) The sub-select queries both have multiple sub-select queries of their own that I'm not showing so as not to clutter the statement. One of the developers on my team thinks a view would be better. I disagree in that the SQL statement uses variables passed in by the program (based on the user's login Id). Are there any hard and fast rules on when a view should be used vs. using a SQL statement? What kind of performance gain issues are there in running SQL statements on their own against regular tables vs. against views. (Note that all the joins / where conditions are against indexed columns, so that shouldn't be an issue.) EDIT for clarification... Here's the query I'm working with: select obj_id from object where obj_id in( (select distinct(sec_id) from security where sec_type_id = 494 and ( (sec_usergroup_id = 3278 and sec_usergroup_type_id = 230) or (sec_usergroup_id in (select ug_gi_id from user_group where ug_ui_id = 3278) and sec_usergroup_type_id = 231) ) and sec_obj_id in ( select obj_id from object where obj_ot_id in (select of_ot_id from obj_form left outer join obj_type on ot_id = of_ot_id where ot_app_id = 87 and of_id in (select sec_obj_id from security where sec_type_id = 493 and ( (sec_usergroup_id = 3278 and sec_usergroup_type_id = 230) or (sec_usergroup_id in (select ug_gi_id from user_group where ug_ui_id = 3278) and sec_usergroup_type_id = 231) ) ) and of_usage_type_id = 131 ) ) ) ) or (obj_ot_id in (select of_ot_id from obj_form left outer join obj_type on ot_id = of_ot_id where ot_app_id = 87 and of_id in (select sec_obj_id from security where sec_type_id = 493 and ( (sec_usergroup_id = 3278 and sec_usergroup_type_id = 230) or (sec_usergroup_id in (select ug_gi_id from user_group where ug_ui_id = 3278) and sec_usergroup_type_id = 231) ) ) and of_usage_type_id = 131 ) and obj_id not in (select sec_obj_id from security where sec_type_id = 494) )

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  • postgresql help with php loop....

    - by KnockKnockWhosThere
    I keep getting an "Notice: Undefined index: did" error with this query, and I'm not understanding why... I'm much more used to mysql, so, maybe the syntax is wrong? This is the php query code: function get_demos() { global $session; $demo = array(); $result = pg_query("SELECT DISTINCT(did,vid,iid,value) FROM dv"); if(pg_num_rows($result) > 0) { while($r = pg_fetch_array($result)) { switch($r['did']) { case 1: $demo['a'][$r['vid']] = $r['value']; break; case 2: $demo['b'][$r['vid']] = $r['value']; break; case 3: $demo['c'][$r['vid']] = $r['value']; break; } } } else { $session->session_setMessage(2); } return $demo; } When I run that query at the pg prompt, I get results: "(1,1,1,"A")" "(1,2,2,"B")" "(1,3,3,"C")" "(1,4,4,"D")" "(1,5,5,"E")" "(1,6,6,"F")" "(1,7,7,"G")" "(1,8,8,"H")" "(1,9,9,"I")" "(1,10,A,"J")" "(1,11,B,"K")" "(1,12,C,"L")" "(1,13,D,"M")" "(2,14,1,"A")" "(2,15,2,"B")" "(2,16,0,"C")" "(3,17,1,"A")" "(3,18,2,"B")" "(3,19,3,"C")" "(3,20,4,"D")" "(3,21,5,"E")" "(3,22,6,"F")" "(3,23,7,"G")"

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  • How to update GUI thread/class from worker thread/class?

    - by user315182
    First question here so hello everyone. The requirement I'm working on is a small test application that communicates with an external device over a serial port. The communication can take a long time, and the device can return all sorts of errors. The device is nicely abstracted in its own class that the GUI thread starts to run in its own thread and has the usual open/close/read data/write data basic functions. The GUI is also pretty simple - choose COM port, open, close, show data read or errors from device, allow modification and write back etc. The question is simply how to update the GUI from the device class? There are several distinct types of data the device deals with so I need a relatively generic bridge between the GUI form/thread class and the working device class/thread. In the GUI to device direction everything works fine with [Begin]Invoke calls for open/close/read/write etc. on various GUI generated events. I've read the thread here (How to update GUI from another thread in C#?) where the assumption is made that the GUI and worker thread are in the same class. Google searches throw up how to create a delegate or how to create the classic background worker but that's not at all what I need, although they may be part of the solution. So, is there a simple but generic structure that can be used? My level of C# is moderate and I've been programming all my working life, given a clue I'll figure it out (and post back)... Thanks in advance for any help.

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  • Which database I can used and relationship in it ??

    - by mimo-hamad
    My projece make me confused which I didn't find clear things that make me understand the required database and the relationships in it So, would a super one help me to solve it ?!! ;D this is required: 1) Model the data stored in the database (Identify the entities, roles, relationships, constraints, etc.) 2) Write the Oracle commands to create the database, find appropriate data, and populate the database 3) Write five different queries on your database, using the SELECT/FROM/WHERE construct provided in SQL. Your five queries should illustrate several different aspects of database querying, such as: a. Queries over more than one relation (by listing more than one relation in the FROM clause) b. Queries involving aggregate functions, such as SUM, COUNT, and AVG c. Queries involving complicated selects and joins d. Queries involving GROUP BY, HAVING or other similar functions. e. Queries that require the use of the DISTINCT keyword. And this the condition that we need to determine it to solve the required Q's above : 5) It is desired to develop an Internet membership club to buy products at special prices online. To join, new members must be referred by another existing member of the club. The system will keep the following information for each member: The member ID, referring member, birth date, member name, address, phone, mobile, credit card type, number and expiration date. The items are always shipped to the member's address noted in the membership application. The shipping fees will differ for each order.For each item to be requested, the member will select an item from a long list of possible items. For each item in the database, we store an item ID, an item name, description, and list price. The list price will be different from the actual sale price. The available quantity and the back-ordered quantity (the back-ordered quantity is the quantity on-order by the club from its suppliers) is also noted

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  • Newb Question: scanf() in C

    - by riemannliness
    So I started learning C today, and as an exercise i was told to write a program that asks the user for numbers until they type a 0, then adds the even ones and the odd ones together. Here is is (don't laugh at my bad style): #include <stdio.h>; int main() { int esum = 0, osum = 0; int n, mod; puts("Please enter some numbers, 0 to terminate:"); scanf("%d", &n); while (n != 0) { mod = n % 2; switch(mod) { case 0: esum += n; break; case 1: osum += n; } scanf("%d", &n); } printf("The sum of evens:%d,\t The sum of odds:%d", esum, osum); return 0; } My question concerns the mechanics of the scanf() function. It seems that when you enter several numbers at once separated by spaces (eg. 1 22 34 2 8), the scanf() function somehow remembers each distinct numbers in the line, and steps through the while loop for each one respectively. Why/how does this happen? Example interaction within command prompt: - Please enter some numbers, 0 to terminate: 42 8 77 23 11 (enter) 0 (enter) - The sum of evens:50, The sum of odds:111 I'm running the program through the command prompt, it's compiled for win32 platforms with visual studio.

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  • Oracle SQL: ROLLUP not summing correctly

    - by tommy-o-dell
    Hi guys, Rollup seems to be working correcly to count the number of units, but not the number of trains. Any idea what could be causing that? The output from the query looks like this. The sum of the Units column in yellow is 53 but the rollup is showing 51. The number of units adds up correctly though... And here's the oracle SQL query... select t.year, t.week, decode(t.mine_id,NULL,'PF',t.mine_id) as mine_id, decode(t.product,Null,'LF',t.product) as product, decode(t.mine_id||'-'||t.product,'-','PF',t.mine_id||'-'||t.product) as code, count(distinct t.tpps_train_id) as trains, count(1) as units from ( select trn.mine_code as mine_id, trn.train_tpps_id as tpps_train_id, round((con.calibrated_weight_total - con.empty_weight_total),2) as tonnes from widsys.train trn INNER JOIN widsys.consist con USING (train_record_id) where trn.direction = 'N' and (con.calibrated_weight_total-con.empty_weight_total) > 10 and trn.num_cars > 10 and con.consist_no not like '_L%' ) w, ( select to_char(td.datetime_act_comp_dump-7/24, 'IYYY') as year, to_char(td.datetime_act_comp_dump-7/24, 'IW') as week, td.mine_code as mine_id, td.train_id as tpps_train_id, pt.product_type_code as product from tpps.train_details td inner join tpps.ore_products op using (ore_product_key) inner join tpps.product_types pt using (product_type_key) where to_char(td.datetime_act_comp_dump-7/24, 'IYYY') = 2010 and to_char(td.datetime_act_comp_dump-7/24, 'IW') = 12 order by td.datetime_act_comp_dump asc ) t where w.mine_id = t.mine_id and w.tpps_train_id = t.tpps_train_id having t.product is not null or t.mine_id is null group by t.year, t.week, rollup( t.mine_id, t.product)

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  • Beginner Question: For extract a large subset of a table from MySQL, how does Indexing, order of tab

    - by chongman
    Sorry if this is too simple, but thanks in advance for helping. This is for MySQL but might be relevant for other RDMBSs tblA has 4 columns: colA, colB, colC, mydata, A_id It has about 10^9 records, with 10^3 distinct values for colA, colB, colC. tblB has 3 columns: colA, colB, B_id It has about 10^4 records. I want all the records from tblA (except the A_id) that have a match in tblB. In other words, I want to use tblB to describe the subset that I want to extract and then extract those records from tblA. Namely: SELECT a.colA, a.colB, a.colC, a.mydata FROM tblA as a INNER JOIN tblB as b ON a.colA=b.colA a.colB=b.colB ; It's taking a really long time (more than an hour) on a newish computer (4GB, Core2Quad, ubuntu), and I just want to check my understanding of the following optimization steps. ** Suppose this is the only query I will ever run on these tables. So ignore the need to run other queries. Now my questions: 1) What indexes should I create to optimize this query? I think I just need a multiple index on (colA, colB) for both tables. I don't think I need separate indexes for colA and colB. Another stack overflow article (that I can't find) mentioned that when adding new indexes, it is slower when there are existing indexes, so that might be a reason to use the multiple index. 2) Is INNER JOIN correct? I just want results where a match is found. 3) Is it faster if I join (tblA to tblB) or the other way around, (tblB to tblA)? This previous answer says that the optimizer should take care of that. 4) Does the order of the part after ON matter? This previous answer say that the optimizer also takes care of the execution order.

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  • How do I establish table association in JPA / Hibernate with existing database?

    - by Paperino
    Currently I have two tables in my database Encounters and Referrals: There is a one to many relationship between these two tables. Currently they are linked together with foreign keys. Right now I have public class Encounter extends JPASupport implements java.io.Serializable { @Column(name="referralid", unique=false, nullable=true, insertable=true, updatable=true) public Integer referralid; } But what I really want is public class Encounter extends JPASupport implements java.io.Serializable { .......... @OneToMany(cascade=CascadeType.PERSIST) public Set<Referrals> referral; ............ } So that I can eventually do a query like this: List<Encounter> cases = Encounter.find( "select distinct p from Encounter p join p.referrals as t where t.caseid =103" ).fetch(); How do I tell JPA that even though I have non-standard column names for my foreign keys and primary keys that its the object models that I want linked, not simply the integer value for the keys? Does this make sense? I hope so. Thanks in advanced!

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  • How to prepare data for display on a silverlight chart using WCF RIA Services + Entity Framework

    - by Banford
    I've used WCF RIA services with Entity Framework to build a simple application which can display and updates data about school courses. This was done by following the Microsoft tutorials. Now I would like to have a chart which shows a count for how many courses are on a key stage. Example: Key Stage 3 - 20 courses Key Stage 4 - 32 courses Key Stage 5 - 12 courses Displayed on any form of chart. I have no problem binding data to the chart in XAML. My problem is that I do not know how to correct way of getting the data into that format. The generated CRUD methods are basic. I have a few thoughts about possible ways, but don't know which is correct, they are: Create a View in SQL server and map this to a separate Entity in the Entity Data Model. Generating new CRUD methods for this automatically. Customise the read method in the existing DomainService using .Select() .Distinct() etc. Don't know this syntax very well labda expressions/LINQ??? what is it? Any good quickstarts on it? Create a new class to store only the data required and create a read method for it. Tried this but didn't know how to make it work without a matching entity in the entity model. Something I am not aware of. I'm very new to this and struggling with the concepts so if there are useful blogs or documentation I've missed feel free to point me towards them. But I'm unsure of the terminology to use in my searches at the moment.

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  • Creating an appropriate index for a frequently used query in SQL Server

    - by Slauma
    In my application I have two queries which will be quite frequently used. The Where clauses of these queries are the following: WHERE FieldA = @P1 AND (FieldB = @P2 OR FieldC = @P2) and WHERE FieldA = @P1 AND FieldB = @P2 P1 and P2 are parameters entered in the UI or coming from external datasources. FieldA is an int and highly on-unique, means: only two, three, four different values in a table with say 20000 rows FieldB is a varchar(20) and is "almost" unique, there will be only very few rows where FieldB might have the same value FieldC is a varchar(15) and also highly distinct, but not as much as FieldB FieldA and FieldB together are unique (but do not form my primary key, which is a simple auto-incrementing identity column with a clustered index) I'm wondering now what's the best way to define an index to speed up specifically these two queries. Shall I define one index with... FieldB (or better FieldC here?) FieldC (or better FieldB here?) FieldA ... or better two indices: FieldB FieldA and FieldC FieldA Or are there even other and better options? What's the best way and why? Thank you for suggestions in advance!

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  • C# algorithm for figuring out different possible combinations...

    - by ttomsen
    I have 10 boxes, each box can hold one item from a group/type of items, each 'group' type only fits in one of the 10 box types. The pool can have n number of items. The groups have completely distinct items. Each item has a price, i want an algorithm that will generate all the different possibilities, so i can figure out different price points. so a smaller picture of the problem BOX A - can have item 1,2,3,4 in it BOX B - can have item 6,7,8,9,10,11,12 BOX C - can have item 13,15,16,20,21 The items are stored in a db, they have a column which denotes which box they can go in. All box types are stored in an array, and I can put the items in a generic list. Anyone see a straightforward way to do this. I have tried doing 10 nested foreach's to see if i could find a simpler way. The nested loops will take MANY hours to run. the nested for each's basically pull all combinations, then calculate a rank for each combination, and store the top 10 ranked combination of items for output

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  • How can I optimize the SELECT statement running on an Oracle database?

    - by Elvis Lou
    I have a SELECT statement in ORACLE: SELECT COUNT(DISTINCT ds1.endpoint_msisdn) multiple30, dss1.service, dss1.endpoint_provisioning_id, dss1.company_scope, Nvl(x.subscription_status, dss1.subscription_status) subscription_status FROM daily_summary ds1 join daily_summary ds2 ON ds1.endpoint_msisdn = ds2.endpoint_msisdn, daily_summary_static dss1, daily_summary_static dss2, (SELECT NULL subscription_status FROM dual UNION ALL SELECT -2 subscription_status FROM dual) x WHERE ds1.summary_ts >= To_date('10-04-2012', 'dd-mm-yyyy') - 30 AND ds1.summary_ts <= To_date('10-04-2012', 'dd-mm-yyyy') AND dss1.last_active >= To_date('10-04-2012', 'dd-mm-yyyy') - 30 AND dss1.last_active <= To_date('10-04-2012', 'dd-mm-yyyy') AND dss2.last_active >= To_date('10-04-2012', 'dd-mm-yyyy') - 30 AND dss2.last_active <= To_date('10-04-2012', 'dd-mm-yyyy') AND dss1.service <> dss2.service AND ( dss1.company_scope = 2 OR dss1.company_scope = 5 ) AND ( dss2.company_scope = 2 OR dss2.company_scope = 5 ) AND dss1.company_scope = dss2.company_scope AND ds1.endpoint_noc_id = dss1.endpoint_noc_id AND ds1.endpoint_host_id = dss1.endpoint_host_id AND ds1.endpoint_instance_id = dss1.endpoint_instance_id AND ds2.endpoint_noc_id = dss2.endpoint_noc_id AND ds2.endpoint_host_id = dss2.endpoint_host_id AND ds2.endpoint_instance_id = dss2.endpoint_instance_id AND dss1.endpoint_provisioning_id = dss2.endpoint_provisioning_id AND Least(1, ds1.total_actions) = 1 AND Least(1, ds2.total_actions) = 1 GROUP BY dss1.service, dss1.endpoint_provisioning_id, dss1.company_scope, Nvl(x.subscription_status, dss1.subscription_status); This query took about 26 minutes to return in my environment, but if I remove the section: dss1.last_active >= to_date('10-04-2012','dd-mm-yyyy') - 30 AND dss1.last_active <= to_date('10-04-2012','dd-mm-yyyy') AND dss2.last_active >= to_date('10-04-2012','dd-mm-yyyy') - 30 AND dss2.last_active <= to_date('10-04-2012','dd-mm-yyyy') AND it only took 20 seconds to run. We have index on the column last_active, I don't know why the section slow down the performance so much? any ideas?

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  • Improve Log Exceptions

    - by Jaider
    I am planning to use log4net in a new web project. In my experience, I see how big the log table can get, also I notice that errors or exceptions are repeated. For instance, I just query a log table that have more than 132.000 records, and I using distinct and found that only 2.500 records are unique (~2%), the others (~98%) are just duplicates. so, I came up with this idea to improve logging. Having a couple of new columns: counter and updated_dt, that are updated every time try to insert same record. If want to track the user that cause the exception, need to create a user_log or log_user table, to map N-N relationship. Create this model may made the system slow and inefficient trying to compare all these long text... Here the trick, we should also has a hash column of binary of 16 or 32, that hash the message and the exception, and configure an index on it. We can use HASHBYTES to help us. I am not an expert in DB, but I think that will made the faster way to locate a similar record. And because hashing doesn't guarantee uniqueness, will help to locale those similar record much faster and later compare by message or exception directly to make sure that are unique. This is a theoretical/practical solution, but will it work or bring more complexity? what aspects I am leaving out or what other considerations need to have? the trigger will do the job of insert or update, but is the trigger the best way to do it?

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  • N-gram split function for string similarity comparison

    - by Michael
    As part of excersise to better understand F# which I am currently learning , I wrote function to split given string into n-grams. 1) I would like to receive feedback about my function : can this be written simpler or in more efficient way? 2) My overall goal is to write function that returns string similarity (on 0.0 .. 1.0 scale) based on n-gram similarity; Does this approach works well for short strings comparisons , or can this method reliably be used to compare large strings (like articles for example). 3) I am aware of the fact that n-gram comparisons ignore context of two strings. What method would you suggest to accomplish my goal? //s:string - target string to split into n-grams //n:int - n-gram size to split string into let ngram_split (s:string, n:int) = let ngram_count = s.Length - (s.Length % n) let ngram_list = List.init ngram_count (fun i -> if( i + n >= s.Length ) then s.Substring(i,s.Length - i) + String.init ((i + n) - s.Length) (fun i -> "#") else s.Substring(i,n) ) let ngram_array_unique = ngram_list |> Seq.ofList |> Seq.distinct |> Array.ofSeq //produce tuples of ngrams (ngram string,how much occurrences in original string) Seq.init ngram_array_unique.Length (fun i -> (ngram_array_unique.[i], ngram_list |> List.filter(fun item -> item = ngram_array_unique.[i]) |> List.length) )

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  • table subtraction challenge

    - by Valentin
    I have a challenge that I haven’t overcome in the last two days using Stored Procedures and SQL 2008. I took several approaches but must fell short. One appraoch very interesting was using a table substraction. It’s really all about table subtraction. I was wondering if you could help me crack this one. Here is the challenge: Two tables 1Testdb y 2Testdb. My first step was to select ID relationships ([2Testdb].Acc_id) on table 2Testdb for one given individual ([2Testdb].Bus_id). Then query table 1Testdb for records not mathcing my original selection from 2Testdb. But other approaches are welcome. Data and Structures: USE [Challengedb] GO SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[1Testdb]( [Acc_id] [uniqueidentifier] NULL [Name] [Varchar(10)] NULL ) ON [PRIMARY] GO CREATE TABLE [dbo].[2Testdb]( [Acc_id] [uniqueidentifier] NULL, [Bus_id] [uniqueidentifier] NULL ) ON [PRIMARY] GO Records on 1Testdb: 34455F60-9474-4521-804E-66DB39A579F3, John C23523F6-2309-4F58-BB3F-EF7486C7AF8B, Pete DC711615-3BE4-4B31-9EF2-B1314185CA62, Dave E3AAB073-2398-476D-828B-92829F686A4C, Adam Records on 2Testdb: (Relationship table, ex. Friend relationships) Record #1: DC711615-3BE4-4B31-9EF2-B1314185CA62, 34455F60-9474-4521-804E-66DB39A579F3 Record #2: E3AAB073-2398-476D-828B-92829F686A4C, 34455F60-9474-4521-804E-66DB39A579F3 Record # 3: DC711615-3BE4-4B31-9EF2-B1314185CA62, E3AAB073-2398-476D-828B-92829F686A4C Record # 4: E3AAB073-2398-476D-828B-92829F686A4C, DC711615-3BE4-4B31-9EF2-B1314185CA62 Challenge: Select from table 1Testdb only those records distinct that may not have a relationship with John [34455F60-9474-4521-804E-66DB39A579F3] on table 2Testdb. Expected result should be (Who does John doesn’t have relationship with?): C23523F6-2309-4F58-BB3F-EF7486C7AF8B, Pete Thank you, Valentin

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  • Refactoring - Speed increase

    - by Michael G
    How can I make this function more efficient. It's currently running at 6 - 45 seconds. I've ran dotTrace profiler on this specific method, and it's total time is anywhere between 6,000ms to 45,000ms. The majority of the time is spent on the "MoveNext" and "GetEnumerator" calls. and example of the times are 71.55% CreateTableFromReportDataColumns - 18, 533* ms - 190 calls -- 55.71% MoveNext - 14,422ms - 10,775 calls What can I do to speed this method up? it gets called a lot, and the seconds add up: private static DataTable CreateTableFromReportDataColumns(Report report) { DataTable table = new DataTable(); HashSet<String> colsToAdd = new HashSet<String> { "DataStream" }; foreach (ReportData reportData in report.ReportDatas) { IEnumerable<string> cols = reportData.ReportDataColumns.Where(c => !String.IsNullOrEmpty(c.Name)).Select(x => x.Name).Distinct(); foreach (var s in cols) { if (!String.IsNullOrEmpty(s)) colsToAdd.Add(s); } } foreach (string col in colsToAdd) { table.Columns.Add(col); } return table; }

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  • Help with SQL Server query

    - by Travis
    Sorry* this is what I should have put My query is creating duplicate entries for any record that has more than 1 instance (regardless of date) <asp:SqlDataSource ID="EastMonthlyHealthDS" runat="server" ConnectionString="<%$ ConnectionStrings:SNA_TRTTestConnectionString %>" SelectCommand="SELECT [SNA_Parent_Accounts].[Company], (SELECT [Monthly_HIP_Reports].[AccountHealth] from [Monthly_HIP_Reports] where ([Monthly_HIP_Reports].[YearMonth] = @ToDtRFC) AND ([SNA_Parent_Accounts].[CompID] = [Monthly_HIP_Reports].[CompID])) as [AccountHealth], [SNA_Parent_Accounts].[CompID] FROM [SNA_Parent_Accounts] LEFT OUTER JOIN [Monthly_HIP_Reports] ON [Monthly_HIP_Reports].[CompID] = [SNA_Parent_Accounts].[CompID] WHERE (([SNA_Parent_Accounts].[Classification] = 'Business') OR ([SNA_Parent_Accounts].[Classification] = 'Business Ihn')) AND ([SNA_Parent_Accounts].[Status] = 'active') AND ([SNA_Parent_Accounts].[Region] = 'east') ORDER BY [SNA_Parent_Accounts].[Company]"> <SelectParameters> <asp:ControlParameter ControlID="ddMonths" Name="ToDtRFC" PropertyName="Text" Type="String" /> </SelectParameters> </asp:SqlDataSource> Using SELECT DISTINCT appears to correct the problem, but I don't consider that a solution. There are no duplicate entries in the database. So it appears my query is superfically creating duplicates. The query should grab a list of companies that meet the criteria in the where clause, but also grab the Health status for each company in that particular [YearMonth] if present which is what the subquery is for. If an entry for that YearMonth is not present, then leave the Health status blank. but as stated earlier.. if you have an entry say for 2009-03 for CompID 2 and an entry for 2009-04 for CompID 2.. Doesn't matter what month you select it will list that company 2-3 times.

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  • Heavy Mysql operation & Time Constraints [closed]

    - by Rahul Jha
    There is a performance issue where that I have stuck with my application which is based on PHP & MySql. The application is for Data Migration where data has to be uploaded and after various processes (Cleaning from foreign characters, duplicate check, id generation) it has to be inserted into one central table and then to 5 different tables. There, an id is generated and that id has to be updated to central table. There are different sets of records and validation rules. The problem I am facing is that when I insert say(4K) rows file (containing 20 columns) it is working fine within 15 min it gets inserted everywhere. But, when I insert the same records again then at this time it is taking one hour to insert (ideally it should get inserted by marking earlier inserted data as duplicate). After going through the log file, I noticed is that there is a Mysql select statement where I am checking the duplicates and getting ID which are duplicates. Then I am calling a function inside for loop which is basically inserting records into 5 tables and updates id to central table. This Calling function is major time of whole process. P.S. The records has to be inserted record by record.. Kindly Suggest some solution.. //This is that sample code $query=mysql_query("SELECT DISTINCT p1.ID FROM table1 p1, table2 p2, table3 a WHERE p2.datatype =0 AND (p1.datatype =1 || p1.datatype=2) AND p2.ID =0 AND p1.ID = a.ID AND p1.coulmn1 = p2.column1 AND p1.coulmn2 = p2.coulmn2 AND a.coulmn3 = p2.column3"); $num=mysql_num_rows($query); for($i=0;$i<$num;$i++) { $f=mysql_result($query,$i,"ID"); //calling function RecordInsert($f); }

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  • A question about entities, roles and interfaces in Entity Framework 4.

    - by mvole
    Hi, I am an experienced .NET developer but new to EF - so please bear with me. I will use an example of a college application to illustrate my problem. I have these user roles: Lecturer, Student, Administrator. In my code I envisage working with these entities as distinct classes so e.g. a Lecturer teaches a collection of Students. And work with 'is Student' 'TypeOf' etc. Each of these entities share lots of common properties/methods e.g. they can all log onto the system and do stuff related to their role. In EF designer I can create a base entity Person (or User...) and have Lecturer, Student and Administrator all inherit from that. The difficulty I have is that a Lecturer can be an Administrator - and in fact on occasion a Student can be a Lecturer. If I were to add other entities such as Employee and Warden then this gets even more of an issue. I could presumably work with Interfaces so a person could implement ILecturer and IStudent, however I do not see how this fits within EF. I would like to work within the EF designer if possible and I'm working model-first (coding in C#). So any help and advice/samples would be very welcome and much appreciated. Thanks

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  • Retrieving models from form with ModelMultipleChoiceField

    - by colinjameswebb
    I am having difficulties with forms, specifically ModelMultipleChoiceField. I've pieced together this code from various examples, but it sadly doesn't work. I would like to be able to: Search for some Works on work_search.html Display the results of the search, with checkboxes next to each result Select the Works I want, via the checkboxes After pressing Add, display which works were selected. I believe everything is okay except the last part. The page simply displays "works" :( Here is the code - sorry about the length. Models.py class Work(models.Model): title = models.CharField(max_length=200) artist = models.CharField(max_length=200) writers = models.CharField(max_length=200) def __unicode__(self): return self.title + ' - ' + self.artist forms.py class WorkSelectForm(forms.Form): def __init__(self, queryset, *args, **kwargs): super(WorkSelectForm, self).__init__(*args, **kwargs) self.fields['works'] = forms.ModelMultipleChoiceField(queryset=queryset, widget=forms.CheckboxSelectMultiple()) views.py def work_search(request): query = request.GET.get('q', '') if query: qset = ( Q(title__icontains=query) | Q(artist__icontains=query) | Q(writers__icontains=query) ) results = Work.objects.filter(qset).distinct() form = WorkSelectForm(results) return render_to_response("work_search.html", {"form": form, "query": query }) else: results = [] return render_to_response("work_search.html", {"query": query }) def add_works(request): #if request.method == POST: form = WorkSelectForm(request.POST) #if form.isvalid(): items = form.fields['works'].queryset return render_to_response("add_works.html", {"items":items}) work_search.html {% extends "base.html" %} {% block content %} <h1>Search</h1> <form action="." method="GET"> <label for="q">Search: </label> <input type="text" name="q" value="{{ query|escape }}"> <input type="submit" value="Search"> </form> {% if query %} <h2>Results for "{{ query|escape }}":</h2> <form action="add_works" method="post"> <ul> {% if form %} {{ form.as_ul }} {% endif %} </ul> <input type="submit" value="Add"> </form> {% endif %} {% endblock %} add_works.html {% extends "base.html" %} {% block content %} {% if items %} {% for item in items %} {{ item }} {% endfor %} {% else %} <p>Nothing selected</p> {% endif %} {% endblock %}

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