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  • How can I execute a .sql from C#?

    - by J. Pablo Fernández
    For some integration tests I want to connect to the database and run a .sql file that has the schema needed for the tests to actually run, including GO statements. How can I execute the .sql file? (or is this totally the wrong way to go?) I've found a post in the MSDN forum showing this code: using System.Data.SqlClient; using System.IO; using Microsoft.SqlServer.Management.Common; using Microsoft.SqlServer.Management.Smo; namespace ConsoleApplication1 { class Program { static void Main(string[] args) { string sqlConnectionString = "Data Source=(local);Initial Catalog=AdventureWorks;Integrated Security=True"; FileInfo file = new FileInfo("C:\\myscript.sql"); string script = file.OpenText().ReadToEnd(); SqlConnection conn = new SqlConnection(sqlConnectionString); Server server = new Server(new ServerConnection(conn)); server.ConnectionContext.ExecuteNonQuery(script); } } } but on the last line I'm getting this error: System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. --- System.TypeInitializationException: The type initializer for '' threw an exception. --- .ModuleLoadException: The C++ module failed to load during appdomain initialization. --- System.DllNotFoundException: Unable to load DLL 'MSVCR80.dll': The specified module could not be found. (Exception from HRESULT: 0x8007007E). I was told to go and download that DLL from somewhere, but that sounds very hacky. Is there a cleaner way to? Is there another way to do it? What am I doing wrong? I'm doing this with Visual Studio 2008, SQL Server 2008, .Net 3.5SP1 and C# 3.0.

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  • SQL server 2005 agent not working

    - by flaggers
    Sql server 2005 service pack 2 version: 9.00.3042.00 All maintenance plans fail with the same error. The details of the error are:- Execute Maintenance Plan Execute maintenance plan. test7 (Error) Messages Execution failed. See the maintenance plan and SQL Server Agent job history logs for details. The advanced information section shows the following; Job 'test7.Subplan_1' failed. (SqlManagerUI) Program Location: at Microsoft.SqlServer.Management.SqlManagerUI.MaintenancePlanMenu_Run.PerformActions() At this point the following appear in the windows event log: Event Type: Error Event Source: SQLISPackage Event Category: None Event ID: 12291 Date: 28/05/2009 Time: 16:09:08 User: 'DOMAINNAME\username' Computer: SQLSERVER4 Description: Package "test7" failed. and also this: Event Type: Warning Event Source: SQLSERVERAGENT Event Category: Job Engine Event ID: 208 Date: 28/05/2009 Time: 16:09:10 User: N/A Computer: SQLSERVER4 Description: SQL Server Scheduled Job 'test7.Subplan_1' (0x96AE7493BFF39F4FBBAE034AB6DA1C1F) - Status: Failed - Invoked on: 2009-05-28 16:09:02 - Message: The job failed. The Job was invoked by User 'DOMAINNAME\username'. The last step to run was step 1 (Subplan_1). There are no entries in the SQl Agent log at all.

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  • SQL Server CE, Visual Studio 2008/2010 RC, and Linq-to-Sql

    - by blu
    I added an .sdf to my project, added a table, added a Linq-to-Sql dmbl, and tried to add the table to the dbml. The result was an error: "The selected object(s) are an unsupported data provider" This happens in both VS 2008 Professional SP1 and 2010 RC Ultimate. I found someone talking about using SQL Metal to generate the file, but I didn't enjoy that 2 years ago, and after a little playing around I recall why. Does anyone know if this is going to be supported in the release version? Should I abandon SQL Server CE and just use SQLite (with DbLinq)? Thanks for any insight.

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  • Nested SELECT clause in SQL Compact 3.5

    - by Sasha
    In this post "select with nested select" I read that SQL Compact 3.5 (SP1) support nested SELECT clause. But my request not work: t1 - table 1 t2 - table 2 c1, c2 = columns select t1.c1, t1.c2, (select count(t2.c1) from t2 where t2.id = t1.id) as count_t from t1 Does SQL Compact 3.5 SP1 support nested SELECT clause in this case? Update: SQL Compact 3.5 SP1 work with this type of nested request: SELECT ... from ... where .. IN (SELECT ...) SELECT ... from (SELECT ...)

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  • sql db problem with windows authentication

    - by Jimmy
    Have a SQL Server 2008 db which I connect to the Windows Authentication .. has worked good for 7-8 months .. but now when I come to work today it no longer worked to connect, without that I had done something Error message was: Can not open user default database. Login failed. Login failed for user 'Jimmy-PC \ Jimmy'. where the first is the computer name and the second is the user. The problem seems to be that it tries to connect to the default database. Have tried to change it without success .. I do not have sql server management tools for sql 2008 but only to 2005, someone who has similar experience? who have not touched anything said over the weekend and it worked last Friday without any problems.

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  • Write a sql to get the last data

    - by Lu Lu
    Hello everyone, I have a Realtime table with example data: Symbol Date Value ABC 1/3/2009 03:05:01 327 -- is last data for 'ABC' ABC 1/2/2009 03:05:01 326 ABC 1/2/2009 02:05:01 323 ABC 1/2/2009 01:05:01 313 BBC 1/3/2009 03:05:01 458 -- is last data for 'BBC' BBC 1/2/2009 03:05:01 454 BBC 1/2/2009 02:05:01 453 BBC 1/2/2009 01:05:01 423 Please help me to write a sql to return last data for all symbol. The result is: Symbol Date Value ABC 1/3/2009 03:05:01 327 BBC 1/3/2009 03:05:01 458 P/s: I use sql server 2005. And Realtime data is very big, please optimize the sql code. Thanks.

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  • SQL Server ORDER BY/WHERE with nested select

    - by Echilon
    I'm trying to get SQL Server to order by a column from a nested select. I know this isn't the best way of doing this but it needs to be done. I have two tables, Bookings and BookingItems. BookingItems contains StartDate and EndDate fields, and there can be multiple BookingItems on a Booking. I need to find the earliest startdate and latest end date from BookingItems, then filter and sort by these values. I've tried with a nested select, but when I try to use one of the selected columns in a WHERE or ORDER BY, I get an "Invalid Column Name". SELECT b.*, (SELECT COUNT(*) FROM bookingitems i WHERE b.BookingID = i.BookingID) AS TotalRooms, (SELECT MIN(i.StartDate) FROM bookingitems i WHERE b.BookingID = i.BookingID) AS StartDate, (SELECT MAX(i.EndDate) FROM bookingitems i WHERE b.BookingID = i.BookingID) AS EndDate FROM bookings b LEFT JOIN customers c ON b.CustomerID = c.CustomerID WHERE StartDate >= '2010-01-01' Am I missing something about SQL ordering? I'm using SQL Server 2008.

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  • creating multiple users for a c#.net winform application using sql server express

    - by sqlchild
    i have a single sql database in sql server express. i have a login MAINLOGIN, for this database. i want insertion of data in this database through multiple users, U1,U2,U3, each having different userids & passwords. These users would be created by MAINLOGIN , manually or via the winform application. So while creating MAINLOGIN , i would give him permission to further create logins. For this what should i do? i cannot create MULTIPLE users, because for one database, only one user can be created under one login. so should i create multiple logins, L1,L2,L3, then map, U1, U2, U3 to them. Or, is there a better way to do this? like application roles etc. i dont want to use windows authentication. because if i know the system password, then i could simply connect sql via the application and insert wrong data.

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  • Use LINQ to SQL results inside SQL Server stored procedure

    - by ifwdev
    Note: I'm not trying to call a SQL Server stored proc using a L2SQL datacontext. I use LINQPad for some fairly complex "reporting" that takes L2SQL output saved to an Array and is processed further. For example, it's usually much easier to do multiple levels of grouping with LINQ to Objects instead of trying to optimize a T-SQL query to run in a reasonable amount of time. What would be the easiest way to take the end result of one of these "applications" and use that in a SQL Server 2008 stored proc? The idea is to use the data for a Reporting Services Report, rather than copying and pasting into Excel (manual labor). The reports need to be accessible on the report server (not using the Report Server control in an application). I could output CSV and read that somehow via command line exec, but that seems like a hack. Thanks for your help.

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  • Cannot login to SQL Server 2008 R2 with Windows authentication

    - by Ian Boyd
    When i try to connect to SQL Server (2008 R2) using Windows authentication: i cannot: Checking the Windows Application event log, i find the error: Login failed for user 'AVATOPIA\ian'. Reason: Token-based server access validation failed with an infrastructure error. Check for previous errors. [CLIENT: ] Log Name: Application Source: MSSQLSERVER Event ID: 18456 Level: Information User: AVATOPIA\ian OpCode: Task Category: Logon i can login to the computer itself using Windows authentication. i can log into SQL Server using the local Windows Administrator account. We can connect to 8 other SQL Servers on the domain using Windows Authentication. Just this one, whitch is the only one that is 2008 R2 is failing. So i assume it's a bug with *2008 R2. Note: i cannot logon locally, or remotely, using Windows authentication. i can login locally and remotely using SQL Server Authentication. Update Note: It's not limited to SQL Server Management Studio, standalone applications that connect using Windows authentication: fail: Note: It's not a client problem, as we can connect fine to other (non-SQL Server 2008 R2 machines): i'm sure there's a technote or knowledge base article describing why SQL Server 2008 R2 is broken by default, but i can't find it. Update 2 Matt figure out the change that Microsoft made so that SQL Server 2008 R2 is broken by default: Administrators are no longer administrators All that remains is to figure out how to make Administrators administrators. One of these days i'm going to start a list of changes around Microsoft's "broken by default" initiative. Steps to reproduce the problem How do i add a group to the sysadmin fixed server role? Here's the steps i try, that don't work: Click Add: Click Object Types: Ensure that you have no ability to add groups: and click OK. Under Enter the object names to select, enter Administrators: Click Check Names, and ensure that you are not allowed to add groups: and click Cancel. Click Browse..., and ensure that you have no ability to add groups: You should now still not have added any group to the sysadmin role. Additional information SQL Server Management Studio is being run as an administrator: SQL Server is set to use Windows Authentication: tried while logged into SQL with both sa and the only other sysadmin domain account (screenshot can be supplied for those who don't believe)

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  • SQL 2008 R2 Named Instance Client Connectivity Issues?

    - by Jerry Dodge
    We're upgrading our software from using SQL 2000 to 2008 R2. Our customers will be installing an update which uninstalls 2000 and installs 2008 R2 under the same instance. So if no instance existed, then no instance name will be set (default). However, the problem starts with the customers which have a named SQL instance. Starting in 2008 R2 (not sure of ones before), for some reason, a client connecting to the server by its instance name is unsuccessful. I'm testing from the Management Studio - if I can't connect this, then nothing can connect. I browse network servers, and find the specific server\instance in the list. But, upon trying to connect to an instance name like MyServer\INST, I get: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) (Microsoft SQL Server, Error: -1) I do in fact have TCP/IP and Named Pipes protocols enabled, this is the first thing I did. When I connect to the server using a comma (,) and port number like MyServer, 49195, it works just fine. So it appears that client computers are just unable to identify the instance names. This has happened on all our installations of SQL 2008 R2 and from all client computers, including Win 7, XP, Vista, Server 2008, and Server 2003. We never experienced such issues on earlier versions of SQL. The problem even persists if the firewalls and antiviruses are all disabled. Now, this is a large update which we will be distributing soon to all our customers, and we want to minimize the interaction they need with us to get this installed. We absolutely hate the idea of using a port number, because it will always be different, and we would have to modify each client to point to this server/port. Some of our customers may have hundreds of client computers. How do I make client connections to a named SQL instance work again? After all, this is the whole purpose of named instances, and if a client can't connect to this instance by its name, then what is it even named for? EDIT It was mentioned to make sure SQL Browser is running, so I checked, and it is running. The server is also able to connect to its self (locally) - just external connections are refused. UPDATE After more careful checking, I learned the firewall wasn't completely disabled when testing, and upon disabling it completely, this works. So it appears that SQL Browser is being blocked by the firewall from external clients from accessing.

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  • What is so bad about using SQL INNER JOIN

    - by Stephen B. Burris Jr.
    Everytime a database diagram gets looked out, one area people are critical of is inner joins. They look at them hard and has questions to see if an inner join really needs to be there. Simple Library Example: A many-to-many relationship is normally defined in SQL with three tables: Book, Category, BookCategory. In this situation, Category is a table that contains two columns: ID, CategoryName. In this situation, I have gotten questions about the Category table, is it need? Can it be used as a lookup table, and in the BookCategory table store the CategoryName instead of the CategoryID to stop from having to do an additional INNER JOIN. (For this question, we are going to ignore the changing, deleting of any CategoryNames) The question is, what is so bad about inner joins? At what point is doing them a negative thing (general guidelines like # of transactions, # of records, # of joins in a statement, etc)?

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  • LINQ to SQL join when there aren't results

    - by Boarder2
    Given the following database structure I'm trying to write a LINQ query that will return images grouped by tags it's associated with. So far I've got this: var images = from img in db.Images join imgTags in db.ImageTags on img.idImage equals imgTags.idImage join t in db.Tags on imgTags.idTag equals t.idTag where img.OCRData.Contains(searchText.Text) group img by new { t.TagName } into aGroup select new { GroupName = aGroup.Key.TagName, Items = from x in aGroup select new ImageFragment() { ImageID = x.idImage, ScanDate = x.ScanTime } }; Which works great. However, I also want to return Images that do not have any tags associated with them in a group of "(Untagged)" or something. I can't wrap my head around how I would do this without inserting a default tag for every image and that seems like generally not a very good solution.

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  • [Newbie] How to join mysql tables

    - by Ivan
    I've an old table like this: user> id | name | address | comments And now I've to create an "alias" table to allow some users to have an alias name for some reasons. I've created a new table 'user_alias' like this: user_alias> name | user But now I have a problem due my poor SQL level... How to join both tables to generate something like this: 1 | my_name | my_address | my_comments 1 | my_alias | my_address | my_comments 2 | other_name | other_address | other_comments I mean, I want to make a "SELECT..." query that returns in the same format as the "user" table ALL users and ALL alias.. Something like this: SELECT user.* FROM user LEFT JOIN user_alias ON `user`=`id` but it doesn't work for me..

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  • Full outer join in django

    - by Ber
    How can I create a query for a full outer join across a M2M relationchip using the django QuerySet API? It that is not supported, some hint about creating my own manager to do this would be welcome. Edited to add: @S.Lott: Thanks for the enlightenment. The need for the OUTER JOIN comes from the application. It has to generate a report showing the data entered, even if it still incomplete. I was not aware of the fact that the result would be a new class/model. Your hints will help me quite a bit.

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  • How to join mysql tables

    - by Ivan
    I've an old table like this: user> id | name | address | comments And now I've to create an "alias" table to allow some users to have an alias name for some reasons. I've created a new table 'user_alias' like this: user_alias> name | user But now I have a problem due my poor SQL level... How to join both tables to generate something like this: 1 | my_name | my_address | my_comments 1 | my_alias | my_address | my_comments 2 | other_name | other_address | other_comments I mean, I want to make a "SELECT..." query that returns in the same format as the "user" table ALL users and ALL alias.. Something like this: SELECT user.* FROM user LEFT JOIN user_alias ON `user`=`id` but it doesn't work for me..

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  • SQL Join a View with a Table

    - by gamerzfuse
    CREATE VIEW qtyorderedview AS SELECT titleditors.title_id, titleditors.ed_id, salesdetails.title_id, salesdetails.qty_shipped FROM titleditors, salesdetails WHERE titleditors.title_id = salesdetails.title_id I am using the above SQL statement to create a view. I need to show Editors First Name, Last Name, City where they shipped more than 50 books. The three tables I have are: create table editors ( ed_id char(11), ed_lname varchar(20), ed_fname varchar(20), ed_pos varchar(12), phone varchar(10), address varchar(30), city varchar(20), state char(2), zip char(5), ed_boss char(11)); create table titleditors ( ed_id char(11), title_id char(6), ed_ord integer); create table salesdetails ( sonum integer, qty_ordered integer, qty_shipped integer, title_id char(6), date_shipped date); Can anyone tell me what the second Join code would be to create this result? My first view works fine, but I don't know how to join it to the second table to achieve this result? I didn't make the tables, I just have to work with what I was given. Thanks in advance!

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  • django left join with null

    - by SledgehammerPL
    The model: class Product(models.Model): name = models.CharField(max_length = 128) def __unicode__(self): return self.name class Receipt(models.Model): name = models.CharField(max_length=128) components = models.ManyToManyField(Product, through='ReceiptComponent') class Admin: pass def __unicode__(self): return self.name class ReceiptComponent(models.Model): product = models.ForeignKey(Product) receipt = models.ForeignKey(Receipt) quantity = models.FloatField(max_length=9) unit = models.ForeignKey(Unit) def __unicode__(self): return unicode(self.quantity!=0 and self.quantity or '') + ' ' + unicode(self.unit) + ' ' + self.product.genitive The idea: there are a components on stock. I'd like to find out which recipes I can made with components which I have. It's not easy - but possible - I made a SQL view, which gets the solution. But I'm learning python and Django so I'd like to make it Django-style ;D The concept of solution: get the set of recipes which has at last one component: list_of_available_components = ReceiptComponent.objects.filter(product__in=list_of_available_products).distinct() list_of_related_receipts = Receipt.objects.filter(receiptcomponent__in = list_of_available_components).distinct() get recipes (from list_of_related_receipts) which has not at last one component list_of_incomplete_recipes = (SELECT * FROM drinkbook_receiptcomponent LEFT JOIN drinkstore_stock_products USING(product_id) WHERE drinkstore_stock_products.stock_id IS NULL AND receipt_id IN (SELECT receipt_id FROM drinkbook_receiptcomponent JOIN drinkstore_stock_products USING(product_id))) get recipes (from list_of_related_receipts) which are not in "list_of_incomplete_recipes"

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  • How to display all the dates between two given dates in SQL

    - by Gopal
    Using SQL server 2000. If the Start date is 06/23/2008 and End date is 06/30/2008 Then I need the Output of query as 06/23/2008 06/24/2008 06/25/2008 . . . 06/30/2008 I Created a Table names as Integer which has 1 Column, column values are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 then I used the below mentioned query Tried Query SELECT DATEADD(d, H.i * 100 + T .i * 10 + U.i, '" & dtpfrom.Value & "') AS Dates FROM integers H CROSS JOIN integers T CROSS JOIN integers U order by dates The above query is displaying 999 Dates only. 999 Dates means (365 + 365 + 269) Dates Only. Suppose I want to select more than 3 Years (01/01/2003 to 01/01/2008). The above query should not suitable. How to modify my query? Or any other query is available for the above condition. Please kindly provide me the Query.

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  • How can I join on a CSV varchar?

    - by mgroves
    I have a varchar field that contains a string like "10,11,12,13". How can I use that CSV string to join to another table with those IDs? Here's the approach I'm taking now: select * from SomeTable a WHERE (',' + @csvString + ',') LIKE '%,' + CONVERT(varchar(25), a.ID) + ',%' Where @csvString is "10,11,12,...". I intend to use this method as a join condition as well. That method works, but it's rather slow (using CAST doesn't improve the speed). I understand that having CSVs in the database like that is usually a very silly idea in most cases, but there's nothing I can do about that.

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  • SELECT subset from two tables and LEFT JOIN results

    - by Doctor Trout
    Hi all, I'm trying to write a bit of SQL for SQLITE that will take a subset from two tables (TableA and TableB) and then perform a LEFT JOIN. This is what I've tried, but this produces the wrong result: Select * from TableA Left Join TableB using(key) where TableA.key2 = "xxxx" AND TableB.key3 = "yyyy" This ignore cases where key2="xxxx" but key3 != "yyyy". I want all the rows from TableA that match my criteria whether or not their corresponding value in TableB matches, but only those rows from TableB that match both conditions. I did manage to solve this by using a VIEW, but I'm sure there must be a better way of doing this. It's just beginning to drive me insane tryng to solve it now. (Thanks for any help, hope I've explained this well enough).

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  • SQL LEFT JOIN help

    - by Stolz
    My scenario: There are 3 tables for storing tv show information; season, episode and episode_translation. My data: There are 3 seasons, with 3 episodes each one, but there is only translation for one episode. My objetive: I want to get a list of all the seasons and episodes for a show. If there is a translation available in a specified language, show it, otherwise show null. My attempt to get serie 1 information in language 1: SELECT season_number AS season,number AS episode,name FROM season NATURAL JOIN episode NATURAL LEFT JOIN episode_trans WHERE id_serie=1 AND id_lang=1 ORDER BY season_number,number result: +--------+---------+--------------------------------+ | season | episode | name | +--------+---------+--------------------------------+ | 3 | 3 | Episode translated into lang 1 | +--------+---------+--------------------------------+ expected result +-----------------+--------------------------------+ | season | episode| name | +-----------------+--------------------------------+ | 1 | 1 | NULL | | 1 | 2 | NULL | | 1 | 3 | NULL | | 2 | 1 | NULL | | 2 | 2 | NULL | | 2 | 3 | NULL | | 3 | 1 | NULL | | 3 | 2 | NULL | | 3 | 3 | Episode translated into lang 1 | +--------+--------+--------------------------------+ Full DB dump http://pastebin.com/Y8yXNHrH

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  • MySQL Join issue

    - by mouthpiec
    Hi, I have the following tables: --table sportactivity-- sport_activity_id, home_team_fk, away_team_fk, competition_id_fk, date, time (tuple example) - 1, 33, 41, 5, 2010-04-14, 05:40:00 --table teams-- team_id, team_name (tuple example) - 1, Algeria Now I have the following SQL statment that I use to extract Team A vs Team B SELECT sport_activity_id, T1.team_name AS TeamA, T2.team_name AS TeamB, DATE_FORMAT( DATE, '%d/%m/%Y' ) AS DATE, DATE_FORMAT( TIME, '%H:%i' ) AS TIME FROM sportactivity JOIN teams T1 ON home_team_fk = T1.team_id JOIN teams T2 ON ( away_team_fk = T2.team_id OR away_team_fk = '0' ) WHERE DATE( DATE ) >= CURDATE( ) ORDER BY DATE( DATE ) My problem is that when team B is empty, I am having irrelevant information .... it seems that it is returning all the combinations. I need a query that when team B is equal to 0, (this can occur in my scenario) I get only Team A - Team B (as 0) once.

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  • Broken count(*) after adding LEFT JOIN

    - by Iain Urquhart
    Since adding the LEFT JOIN to the query below, the count(*) has been returning some strange values, it seems to have added the total rows returned in the query to the 'level': SELECT `n`.*, exp_channel_titles.*, round((`n`.`rgt` - `n`.`lft` - 1) / 2, 0) AS childs, count(*) - 1 + (`n`.`lft` > 1) + 1 AS level, ((min(`p`.`rgt`) - `n`.`rgt` - (`n`.`lft` > 1)) / 2) > 0 AS lower, (((`n`.`lft` - max(`p`.`lft`) > 1))) AS upper FROM `exp_node_tree_6` `n` LEFT JOIN `exp_channel_titles` ON (`n`.`entry_id`=`exp_channel_titles`.`entry_id`), `exp_node_tree_6` `p`, `exp_node_tree_6` WHERE `n`.`lft` BETWEEN `p`.`lft` AND `p`.`rgt` AND ( `p`.`node_id` != `n`.`node_id` OR `n`.`lft` = 1 ) GROUP BY `n`.`node_id` ORDER BY `n`.`lft` I'm totally stumped... Thank you!

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  • Inequality joins, Asynchronous transformations and Lookups : SSIS

    - by jamiet
    It is pretty much accepted by SQL Server Integration Services (SSIS) developers that synchronous transformations are generally quicker than asynchronous transformations (for a description of synchronous and asynchronous transformations go read Asynchronous and synchronous data flow components). Notice I said “generally” and not “always”; there are circumstances where using asynchronous transformations can be beneficial and in this blog post I’ll demonstrate such a scenario, one that is pretty common when building data warehouses. Imagine I have a [Customer] dimension table that manages information about all of my customers as a slowly-changing dimension. If that is a type 2 slowly changing dimension then you will likely have multiple rows per customer in that table. Furthermore you might also have datetime fields that indicate the effective time period of each member record. Here is such a table that contains data for four dimension members {Terry, Max, Henry, Horace}: Notice that we have multiple records per customer and that the [SCDStartDate] of a record is equivalent to the [SCDEndDate] of the record that preceded it (if there was one). (Note that I am on record as saying I am not a fan of this technique of storing an [SCDEndDate] but for the purposes of clarity I have included it here.) Anyway, the idea here is that we will have some incoming data containing [CustomerName] & [EffectiveDate] and we need to use those values to lookup [Customer].[CustomerId]. The logic will be: Lookup a [CustomerId] WHERE [CustomerName]=[CustomerName] AND [SCDStartDate] <= [EffectiveDate] AND [EffectiveDate] <= [SCDEndDate] The conventional approach to this would be to use a full cached lookup but that isn’t an option here because we are using inequality conditions. The obvious next step then is to use a non-cached lookup which enables us to change the SQL statement to use inequality operators: Let’s take a look at the dataflow: Notice these are all synchronous components. This approach works just fine however it does have the limitation that it has to issue a SQL statement against your lookup set for every row thus we can expect the execution time of our dataflow to increase linearly in line with the number of rows in our dataflow; that’s not good. OK, that’s the obvious method. Let’s now look at a different way of achieving this using an asynchronous Merge Join transform coupled with a Conditional Split. I’ve shown it post-execution so that I can include the row counts which help to illustrate what is going on here: Notice that there are more rows output from our Merge Join component than on the input. That is because we are joining on [CustomerName] and, as we know, we have multiple records per [CustomerName] in our lookup set. Notice also that there are two asynchronous components in here (the Sort and the Merge Join). I have embedded a video below that compares the execution times for each of these two methods. The video is just over 8minutes long. View on Vimeo  For those that can’t be bothered watching the video I’ll tell you the results here. The dataflow that used the Lookup transform took 36 seconds whereas the dataflow that used the Merge Join took less than two seconds. An illustration in case it is needed: Pretty conclusive proof that in some scenarios it may be quicker to use an asynchronous component than a synchronous one. Your mileage may of course vary. The scenario outlined here is analogous to performance tuning procedural SQL that uses cursors. It is common to eliminate cursors by converting them to set-based operations and that is effectively what we have done here. Our non-cached lookup is performing a discrete operation for every single row of data, exactly like a cursor does. By eliminating this cursor-in-disguise we have dramatically sped up our dataflow. I hope all of that proves useful. You can download the package that I demonstrated in the video from my SkyDrive at http://cid-550f681dad532637.skydrive.live.com/self.aspx/Public/BlogShare/20100514/20100514%20Lookups%20and%20Merge%20Joins.zip Comments are welcome as always. @Jamiet Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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