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  • Data Modeling Help - Do I add another table, change existing table's usage, or something else?

    - by StackOverflowNewbie
    Assume I have the following tables and relationships: Person - Id (PK) - Name A Person can have 0 or more pets: Pet - Id (PK) - PersonId (FK) - Name A person can have 0 or more attributes (e.g. age, height, weight): PersonAttribute _ Id (PK) - PersonId (FK) - Name - Value PROBLEM: I need to represent pet attributes, too. As it turns out, these pet attributes are, in most cases, identical to the attributes of a person (e.g. a pet can have an age, height, and weight too). How do I represent pet attributes? Do I create a PetAttribute table? PetAttribute Id (PK) PetId (FK) Name Value Do I change PersonAttribute to GenericAttribute and have 2 foreign keys in it - one connecting to Person, the other connecting to Pet? GenericAttribute Id (PK) PersonId (FK) PetId (FK) Name Value NOTE: if PersonId is set, then PetId is not set. If PetId is set, PersonId is not set. Do something else?

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  • Using 'in' in Join

    - by Ruslan
    i have two selects a & b and i join them like: select * from ( select n.id_b || ',' || s.id_b ids, n.name, s.surname from names n, surnames s where n.id_a = s.id_a ) a left join ( select sn.id, sn.second_name ) b on b.id in (a.ids) in this case join doesn't work :( The problem is in b.id in (a.ids). But why if it looks like 12 in (12,24) and no result :(

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  • WPF/.NET data access models - resource recommendations

    - by jasonk
    We're in the early design/prep phases of transferring/updating a rather large "legacy" 3 tier client-server app to a new version. We’re looking at doing WPF over Winforms as it appears to be the direction Microsoft is pushing development of the future and we’d like the maximize the life cycle/span of the apps. That said during the rewrite we’d like to make as many changes to our data access/presentation model to improve performance as much as possible up front as many. I’ve been doing some research along that vein but the vast majority of the resources I've found that discuss WPF focus only simple data tracking apps or focus on the very basics UI design/controls. The few items that even discuss data presentation are fairly elementary in depth. Are there any books/articles/recommended reading/other resources recommended for development related to large enterprise level business apps? Any “gotchas” that should/could be avoided? General advice to minimize the time underwater

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  • COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better?

    - by zneak
    Hello guys, I often find these three variants: SELECT COUNT(*) FROM Foo; SELECT COUNT(1) FROM Foo; SELECT COUNT(PrimaryKey) FROM Foo; As far as I can see, they all do the same thing, and I find myself using the three in my codebase. However, I don't like to do the same thing different ways. To which one should I stick? Is any one of them better than the two others?

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  • Analysis Services with excel as front end - is it possible to get the nicer UI that powerpivot provi

    - by AJM
    I have been looking into PowerPivot and concluded that for "self service BI" and ahoc buidling of cubes it has its uses. In particular I like the enhanced UI that you get from using PowerPivot rather than just using a PivotTable hooked up to an analysis services datasource. However it seems that hooking up PowerPivot to an existing analysis services cube is not a solution for "organisational BI". It is not always desireable to suck millions of rows into excel at once and the interface between PowerPivot and analysis services is very poor in my book. Hence the question is can an existing analysis services solution get the enhanced ui features that power pivot brings, withoout using powerpivot as the design tool? If powerpivot is aimed ad self service/personal BI then it seems bizare that the UI for this is better than for bigger/more costly analysis services solutions.

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  • How to get an id from the results in two tables

    - by Chris Lively
    Consider an order. An order will have one or more line items. Each line item is for a particular product. Given a filter table with a couple of products, how would I get the order id's that had at least all of the products listed in the second table? table Orders( OrderId int ) table LineItems ( OrderId int, LineItemId int, ProductId int ) table Filter ( ProductId int ) data Orders OrderId -------- 1 2 3 LineItems OrderId LineItemId ProductId ------- ---------- --------- 1 1 401 1 2 502 2 3 401 3 4 401 3 5 603 3 6 714 Filter ProductId --------- 401 603 Desired result of the query: OrderId: 3

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  • Querying Two Tables At Once

    - by John
    Hello, I am trying to do what I believe is called a join query. First, in a MySQL table called "login," I want to look up what "loginid" is in the record where "username" equals $profile. (This will be just one record / row in the MySQL table). Then, I want to take that "loginid" and look up all rows / records in a different MySQL table called "submission," and pull data that have that "loginid." This could possibly be more than one record / row. How do I do this? The code below doesn't seem to work. Thanks in advance, John $profile = mysql_real_escape_string($_GET['profile']); $sqlStr = "SELECT l.username, l.loginid, s.loginid, s.submissionid, s.title, s.url, s.datesubmitted, s.displayurl FROM submission AS s, login AS l WHERE l.username = '$profile', s.loginid = l.loginid ORDER BY s.datesubmitted DESC";

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  • Need help with a conditional SELECT statement

    - by Ethan
    I've got a stored procedure with a select statement, like this: `SELECT author_ID, author_name, author_bio FROM Authors WHERE author_ID in (SELECT author_ID from Books) ` This limits results to authors who have book records. This is the Books table: Books book_ID INT author_ID INT book_title NVARCHAR featured_book BIT What I want to do is conditionally select the ID of the featured book by each author as part of the select statement above, and if none of the books for a given author are featured, select the ID of the first (top 1) book by the author from the books table. How do I approach this?

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  • Does the order of columns matter in a group by clause?

    - by Jeff Meatball Yang
    If I have two columns, one with very high cardinality and one with very low cardinality (unique # of values), does it matter in which order I group by? Here's an example: select dimensionName, dimensionCategory, sum(someFact) from SomeFact f join SomeDim d on f.dimensionKey = d.dimensionKey group by d.dimensionName, -- large number of unique values d.dimensionCategory -- small number of unique values Are there situations where it matters?

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  • Using application roles with DataReader

    - by Shahar
    I have an application that should use an application role from the database. I'm trying to make this work with queries that are actually run using Subsonic (2). To do this, I created my own DataProvider, which inherits from Subsonic's SqlDataProvider. It overrides the CreateConnection function, and calls sp_appsetrole to set the application role after the connection is created. This part works fine, and I'm able to get data using the application role. The problem comes when I try to unset the application role. I couldn't find any place in the code where my provider is called after the query is done, so I tried to add my own, by changing SubSonic code. The problem is that Subsonic uses a data reader. It loads data from the data reader, and then closes it. If I unset the application role before the data reader is closed, I get an error saying: There is already an open DataReader associated with this Command which must be closed first. If I unset the application role after the data reader is closed, I get an error saying ExecuteNonQuery requires an open and available Connection. The connection's current state is closed. I can't seem to find a way to close the data reader without closing the connection.

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  • LINQ2SQL: how to merge two columns from the same table into a single list

    - by TomL
    this is probably a simple question, but I'm only a beginner so... Suppose I have a table containing home-work locations (cities) certain people use. Something like: ID(int), namePerson(string), homeLocation(string), workLocation(string) where homeLocation and workLocation can both be null. Now I want all the different locations that are used merged into a single list. Something like: var homeLocation = from hm in Places where hm.Home != null select hm.Home; var workLocation = from wk in Places where wk.Work != null select wk.Work; List<string> locationList = new List<string>(); locationList = homeLocation.Distinct().ToList<string>(); locationList.AddRange(workLocation.Distinct().ToList<string>()); (which I guess would still allow duplicates if they have the same value in both columns, which I don't really want...) My question: how this be put into a single LINQ statement? Thanks in advance for your help!

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  • SCD2 + Merge Statement + MSSQL

    - by Nev_Rahd
    I am trying work out with MERGE statment to Insert / Update Dimension Table of Type SCD2 My source is a Table var to Merge with Dimension table. My Merget statement is throwing an error as: The target table 'DM.DATA_ERROR.ERROR_DIMENSION' of the INSERT statement cannot be on either side of a (primary key, foreign key) relationship when the FROM clause contains a nested INSERT, UPDATE, DELETE, or MERGE statement. Found reference constraint 'FK_ERROR_DIMENSION_to_AUDIT_CreatedBy'. My Merge Statement: DECLARE @DATAERROROBJECT AS [ERROR_DIMENSION] INSERT INTO DM.DATA_ERROR.ERROR_DIMENSION SELECT ERROR_CODE, DATA_STREAM_ID, [ERROR_SEVERITY], DATA_QUALITY_RATING, ERROR_LONG_DESCRIPTION, ERROR_DESCRIPTION, VALIDATION_RULE, ERROR_TYPE, ERROR_CLASS, VALID_FROM, VALID_TO, CURR_FLAG, CREATED_BY_AUDIT_SK, UPDATED_BY_AUDIT_SK FROM (MERGE DM.DATA_ERROR.ERROR_DIMENSION ED USING @DATAERROROBJECT OBJ ON(ED.ERROR_CODE = OBJ.ERROR_CODE AND ED.DATA_STREAM_ID = OBJ.DATA_STREAM_ID) WHEN NOT MATCHED THEN INSERT VALUES( OBJ.ERROR_CODE ,OBJ.DATA_STREAM_ID ,OBJ.[ERROR_SEVERITY] ,OBJ.DATA_QUALITY_RATING ,OBJ.ERROR_LONG_DESCRIPTION ,OBJ.ERROR_DESCRIPTION ,OBJ.VALIDATION_RULE ,OBJ.ERROR_TYPE ,OBJ.ERROR_CLASS ,GETDATE() ,'9999-12-13' ,'Y' ,1 ,1 ) WHEN MATCHED AND ED.CURR_FLAG = 'Y' AND ( ED.[ERROR_SEVERITY] <> OBJ.[ERROR_SEVERITY] OR ED.[DATA_QUALITY_RATING] <> OBJ.[DATA_QUALITY_RATING] OR ED.[ERROR_LONG_DESCRIPTION] <> OBJ.[ERROR_LONG_DESCRIPTION] OR ED.[ERROR_DESCRIPTION] <> OBJ.[ERROR_DESCRIPTION] OR ED.[VALIDATION_RULE] <> OBJ.[VALIDATION_RULE] OR ED.[ERROR_TYPE] <> OBJ.[ERROR_TYPE] OR ED.[ERROR_CLASS] <> OBJ.[ERROR_CLASS] ) THEN UPDATE SET ED.CURR_FLAG = 'N', ED.VALID_TO = GETDATE() OUTPUT $ACTION ACTION_OUT, OBJ.ERROR_CODE ERROR_CODE, OBJ.DATA_STREAM_ID DATA_STREAM_ID, OBJ.[ERROR_SEVERITY] [ERROR_SEVERITY], OBJ.DATA_QUALITY_RATING DATA_QUALITY_RATING, OBJ.ERROR_LONG_DESCRIPTION ERROR_LONG_DESCRIPTION, OBJ.ERROR_DESCRIPTION ERROR_DESCRIPTION, OBJ.VALIDATION_RULE VALIDATION_RULE, OBJ.ERROR_TYPE ERROR_TYPE, OBJ.ERROR_CLASS ERROR_CLASS, GETDATE() VALID_FROM, '9999-12-31' VALID_TO, 'Y' CURR_FLAG, 555 CREATED_BY_AUDIT_SK, 555 UPDATED_BY_AUDIT_SK ) AS MERGE_OUT WHERE MERGE_OUT.ACTION_OUT = 'UPDATE'; What am i doing wrong ?

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  • What's wrong with this SQL query?

    - by ThinkingInBits
    I have two tables: photographs, and photograph_tags. Photograph_tags contains a column called photograph_id (id in photographs). You can have many tags for one photograph. I have a photograph row related to three tags: boy, stream, and water. However, running the following query returns 0 rows SELECT p.* FROM photographs p, photograph_tags c WHERE c.photograph_id = p.id AND (c.value IN ('dog', 'water', 'stream')) GROUP BY p.id HAVING COUNT( p.id )=3 Is something wrong with this query?

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  • Heterogeneous queries require the ANSI_NULLS

    - by Dezigo
    I wrote a trigger. USE [TEST] GO /****** Object: Trigger [dbo].[TR_POSTGRESQL_UPDATE_YC] Script Date: 05/26/2010 08:54:03 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO ALTER TRIGGER [dbo].[TR_POSTGRESQL_UPDATE_YC] ON [dbo].[BCT_CNTR_EVENTS] FOR INSERT AS BEGIN DECLARE @MOVE_TIME varchar(14); DECLARE @MOVE_TIME_FORMATED varchar(20); DECLARE @RELEASE_NOTE varchar(32); DECLARE @CMR_NUMBER varchar(15); DECLARE @MOVE_TYPE varchar(2); SELECT @MOVE_TIME = inserted.move_time ,@MOVE_TYPE = inserted.move_type ,@RELEASE_NOTE = inserted.release_note ,@CMR_NUMBER = inserted.cmr_number FROM inserted IF(@MOVE_TYPE = 'YC') BEGIN SET @MOVE_TIME_FORMATED = SUBSTRING(@MOVE_TIME,1,4) + '-' + SUBSTRING(@MOVE_TIME,5,2) + '-' + SUBSTRING(@MOVE_TIME,7,2) + ' 00:00:00' --UPDATE OpenQuery(POSTGRESQL_SERV,'SELECT visit_cmr,visit_timestamp,visit_pin FROM VISIT') -- SET visit_cmr = @RELEASE_NOTE -- WHERE visit_timestamp = @MOVE_TIME_FORMATED -- AND visit_pin = right(@CMR_NUMBER,5) -- AND visit_cmr IS NULL END SET NOCOUNT ON; END When I have inserted a row,I have get an error **Heterogeneous queries require the ANSI_NULLS and ANSI_WARNINGS options to be set for the connection. This ensures consistent query semantics. Enable these options and then reissue your query.** Then I ofcourse SET SET ANSI_WARNINGS is ON but it`s not work for me. (trigger fo linked server postgresql) I have restarted a server. not work again.

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  • What are the reasons *not* to use a GUID for a primary key?

    - by Yarin
    Whenever I design a database I automatically start with an auto-generating GUID primary key for each of my tables (excepting look-up tables) I know I'll never lose sleep over duplicate keys, merging tables, etc. To me it just makes sense philosophically that any given record should be unique across all domains, and that that uniqueness should be represented in a consistent way from table to table. I realize it will never be the most performant option, but putting performance aside, I'd like to know if there are philosophical arguments against this practice?

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  • How do I convert int? into int

    - by Richard77
    Hello, I've create a SPROC that saves an object and returns the id of the new object saved. Now, I'd like to return an int not an int? public int Save(Contact contact) { int? id; context.Save_And_SendBackID(contact.FirstName, contact.LastName, ref id); //How do I return an int instead of an int? } Thanks for helping

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  • Does clustered index on foreign key column increase join performance vs non-clustered ?

    - by alpav
    In many places it's recommended that clustered indexes are better utilized when used to select range of rows using BETWEEN statement. When I select joining by foreign key field in such a way that this clustered index is used, I guess, that clusterization should help too because range of rows is being selected even though they all have same clustered key value and BETWEEN is not used. Considering that I care only about that one select with join and nothing else, am I wrong with my guess ?

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  • Why does this MySQL function return null?

    - by Shore
    Description: the query actually run have 4 results returned,as can be see from below, what I did is just concate the items then return, but unexpectedly,it's null. I think the code is self-explanatory: DELIMITER | DROP FUNCTION IF EXISTS get_idiscussion_ask| CREATE FUNCTION get_idiscussion_ask(iask_id INT UNSIGNED) RETURNS TEXT DETERMINISTIC BEGIN DECLARE done INT DEFAULT 0; DECLARE body varchar(600); DECLARE created DATETIME; DECLARE anonymous TINYINT(1); DECLARE screen_name varchar(64); DECLARE result TEXT; DECLARE cur1 CURSOR FOR SELECT body,created,anonymous,screen_name from idiscussion left join users on idiscussion.uid=users.id where idiscussion.iask_id=iask_id; DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET done = 1; SET result = ''; OPEN cur1; REPEAT FETCH cur1 INTO body, created, anonymous, screen_name; SET result = CONCAT(result,'<comment><body><![CDATA[',body,']]></body>','<replier>',if(screen_name is not null and !anonymous,screen_name,''),'</replier>','<created>',created,'</created></comment>'); UNTIL done END REPEAT; CLOSE cur1; RETURN result; END | DELIMITER ; mysql> DELIMITER ; mysql> select get_idiscussion_ask(1); +------------------------+ | get_idiscussion_ask(1) | +------------------------+ | NULL | +------------------------+ 1 row in set (0.01 sec) mysql> SELECT body,created,anonymous,screen_name from idiscussion left join users on idiscussion.uid=users.id where idiscussion.iask_id=1; +------+---------------------+-----------+-------------+ | body | created | anonymous | screen_name | +------+---------------------+-----------+-------------+ | haha | 2009-05-27 04:57:51 | 0 | NULL | | haha | 2009-05-27 04:57:52 | 0 | NULL | | haha | 2009-05-27 04:57:52 | 0 | NULL | | haha | 2009-05-27 04:57:53 | 0 | NULL | +------+---------------------+-----------+-------------+ 4 rows in set (0.00 sec) For those who don't think the code is self-explanatory: Why the function returns NULL?

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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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  • Non-Access or -base QBE tool?

    - by idbin.cath0br0
    Hello. I'm currently looking for a QBE tool that can execute queries on PostgreSQL or MySQL. OS doesn't really matter. Reason is that we've got to do QBE at school but I don't want to use neither Microsoft Access nor OpenOffice.org Base (lack of features). Any help would be appreciated.

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