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• How to Store and Retrieve Images Using MsSQL (Server Management Studio)

  - by Joe Majewski

  I am having difficulties when trying to insert files into an MsSQL database. I'll try to break this down as best as I can: What data type should I be using to store image files (jpeg/png/gif/etc)? Right now my table is using the image data type, but I am curious if varbinary would be a better option. How would I go about inserting the image into the database? Does Microsoft SQL Server Management Studio have any built in functions that allow insertions of files into tables? If so, how is that done? Also, how could this be done through the use of an HTML form with PHP handling the input data and placing it into the table? How would I fetch the image from the table and display it on the page? I understand how to SELECT the cell's contents, but how would I go about translating that into a picture. Would I have to have a header(Content type: image/jpeg)? I have no problem doing any of these things with MySQL, but the MsSQL environment is still new to me, and I am working on a project for my job that requires the use of stored procedures to grab various data. Any and all help is appreciated. Thank you very much for your responses!

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• How do I use price data in one table for a calculation that is stored in another table?

  - by shane

  I'm still leanring PHP/MySQL but have learned quite a bit thanks to codies on StackOverflow. I'm trying to setup a sort of room reservations system using two tables: SETUP: Room price table: Has, prices for a type room a client may want to rent as well as the dates (day of week) they wish to use it. Pricing varies based on day of the week and per room. I've setup a different table for each room type as each room type carries different pricing for each day of the week. So, There is an Alpha room table, Bravo room, etc. Within Alpha table are headers for the days of the week with pricing pre-entered into the rows. Client info table: Has the name, address, date of room use, etc data for the specific client. EXAMPLE: Alpha-room price table: Sun = $100; Mon = $200; Tue=$300 and so on. Bravo-room price table: Sun = $100; Mon = $200; Tue=$300 and so on. Client data table: ClientName; date-of-room-use; address; day_subtotal; grand_total. QUESTION: I'm trying to find PHP code that will: look at the date of room use in the client data table, look up the associated cost for that date in the specific room pricing table, record that unit cost in the day subtotal of the client data table and sum a grand total in the grand total row of the client data table (assuming the room may be used more than one day by the customer). I know there's something to do with join but I'm finding it difficult to grasp the concept and, if someone can demonstrate using this example, I think I will have a better understanding of how to work this sort of transaction. Thank you ALL in advance for your suggestions or alternatvie approaches.

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• MS Access (Jet) transactions, workspaces & scope

  - by Eric G

  I am having trouble with committing a transaction (using Access 2003 DAO). It's acting as if I never had called BeginTrans -- I get error 3034 on CommitTrans, "You tried to commit or rollback a transaction without first beginning a transaction"; and the changes are written to the database (presumably because they were never wrapped in a transaction). However, BeginTrans is run, if you step through it. I am running it within the Access environment using the DBEngine(0) workspace. The tables I'm updating are all opened via a Jet database connection (to the same database) and updated using DAO.Recordset.update. The connection is opened before starting BeforeTrans. I'm not doing anything weird in the middle of the transaction like closing/opening connections or multiple workspaces etc. There is one nested transaction level (basically it's wrapping multiple transacted updates in an outer transaction, so if any fail they all fail). The inner transactions run without errors, it's the outer transaction that doesn't work. Here are a few things I've looked into and ruled out: The transaction is spread across several methods and BeginTrans and CommitTrans (and Rollback) are all in different places. But when I tried a simple test of running a transaction this way, it doesn't seem like this should matter. I thought maybe the database connection gets closed when it goes out of local scope, even though I have another 'global' reference to it (I'm never sure what DAO does with dbase connections to be honest). But this seems not to be the case -- right before the commit, the connection and its recordsets are alive (I can check their properties, EOF = False, etc.) My CommitTrans and Rollback are done within event callbacks. (Very basically, a parser program is throwing an 'onLoad' or 'onLoadFail' event at the end of parsing, which I am handling by either committing or rolling back the inserts I made during processing.) However, again, trying a simple test, it doesn't seem like this should matter. Any ideas why this isn't working for me? Thanks.

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• Wnat is the preferred method of building extremely lightweight business object / DAL now that I have

  - by Seth Spearman

  Hello, I have completed a simple database for a project. Only 6tables. Of the 6, one is a "lookup" table. There is one "master" table that is the driver for the system. It is referenced as a foreign key by the other four tables. Give that this step is completed. What is the FASTEST, EASIEST way to create POCOs/BizObjects that can load load the data and the child data. Here are my CAVEATS. *I don't want to spend more than 30-60 minutes learning how? *There is very little biz logic needed in the POCOs. They will pretty much load data. Don't even really need to write back data. *I already know CSLA (up to version 3) but I feel that is overkill for this little project. *Nevertheless, I would love it if it ROOT objects could have collection classes that contain the CHILD objects as in CSLA...but again, without using CSLA. *Please give the answer for .NET 35 but also if I was restricted to only use .NET 20. *Ideally I could just point a tool at the database and the POCOs would be genn'ed. *FREE Just curious what you guys use for this kind of scenario. I understand that this question is subjective but I want to hear a variety of answers. Seth

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• How can you transform a set of numbers into mostly whole ones?

  - by Alice

  Small amount of background: I am working on a converter that bridges between a map maker (Tiled) that outputs in XML, and an engine (Angel2D) that inputs lua tables. Most of this is straight forward However, Tiled outputs in pixel offsets (integers of absolute values), while Angel2D inputs OpenGL units (floats of relative values); a conversion factor between these two is needed (for example, 32px = 1gu). Since OpenGL units are abstract, and the camera can zoom in or out if the objects are too small or big, the actual conversion factor isn't important; I could use a random number, and the user would merely have to zoom in or out. But it would be best if the conversion factor was selected such that most numbers outputted were small and whole (or fractions of small whole numbers), because that makes it easier to work with (and the whole point of the OpenGL units is that they are easy to work with). How would I find such a conversion factor reliably? My first attempt was to use the smallest number given; this resulted in no fractions below 1, but often lead to lots of decimal places where the factors didn't line up. Then I tried the mode of the sequence, which lead to the largest number of 1's possible, but often lead to very long floats for background images. My current approach gets the GCD of the whole sequence, which, when it works, works great, but can easily be thrown off course by a single bad apple. Note that while I could easily just pass the numbers I am given along, or pick some fixed factor, or use one of the conversions I specified above, I am looking for a method to reliably scale this list of integers to small, whole numbers or simple fractions, because this would most likely be unsurprising to the end user; this is not a one off conversion. The end users tend to use 1.0 as their "base" for manipulations (because it's simple and obvious), so it would make more sense for the sizes of entities to cluster around this.

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• charsets in MySQL replication

  - by niklassaers

  Hi guys, What can I do to ensure that replication will use latin1 instead of utf-8? I'm migrating between an MySQL 5.1.22 server (master) on a Linux system and a MySQL 5.1.42 server (slave) on a FreeBSD system. My replication works well, but when non-ascii characters are in my varchars, they turn "weird". The Linux/MySQL-5.1.22 shows the following character set variables: character_set_client=latin1 character_set_connection=latin1 character_set_database=latin1 character_set_filesystem=binary character_set_results=latin1 character_set_server=latin1 character_set_system=utf8 character_sets_dir=/usr/share/mysql/charsets/ collation_connection=latin1_swedish_ci collation_database=latin1_swedish_ci collation_server=latin1_swedish_ci While the FreeBSD shows character_set_client=utf8 character_set_connection=utf8 character_set_database=utf8 character_set_filesystem=binary character_set_results=utf8 character_set_server=utf8 character_set_system=utf8 character_sets_dir=/usr/local/share/mysql/charsets/ collation_connection=utf8_general_ci collation_database=utf8_general_ci collation_server=utf8_general_ci Setting any of these variables from the MySQL CLI has no effect, and setting them in my.cnf or at the command line makes the server not start. Of course, both servers have the tables in question created the same way, in this case with DEFAULT CHARSET=latin1. Let me give you an example: CREATE TABLE `test` ( `test` varchar(5) DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 When I on the master do, in a Latin1 terminal, "INSERT INTO test VALUES ('æøå')", this becomes on the slave, when I select it from a Latin1 based terminal +--------+ | test | +--------+ | æøå | +--------+ On a UTF-8 based terminal on the replication slave, test contains: +--------+ | test | +--------+ | æøå | +--------+ So my conclusion is that it is converted to utf8, even though the table definition is latin1. Is this a correct conclusion? Of course, on the master, in a latin1 terminal, it still says: +------+ | test | +------+ | æøå | +------+ Since both system character sets are utf-8, if I set both terminals to utf-8 and do again "INSERT INTO test VALUES ('æøå')" on the master with a utf-8 terminal, on the slave with utf-8 I get: +------------+ | test | +------------+ | æøà | +------------+ If my conclusion is correct, all my replicated data is converted to utf8 (if it is utf8, it is treated as latin1 and converted to utf8), while all the old data in the table is, as the CREATE TABLE suggests, latin1. I'd love to convert it all to utf-8 if it weren't for the fact that legacy applications rely on it being latin1, so I need to keep it in latin1 while they still exist. What can I do to ensure that the replication reads latin1, treats it as latin1 and writes it on the slave as latin1? Cheers Nik

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• Question about Reporting and Data Warehousing Software bundled with SQL Server 2005

  - by anonymous user

  We currently use SQL Server 2005 Enterprise for our fairly large application, that has its roots in pre SQL Server 7.0. The tables are normalized and designed mainly for the application. The developers for the most part have the legacy SQL Server mindset. Only using the part of TSQL that existed back in 7.0, not using any of the new features of tsql or that are bundled with 2005. We're currently trying to build on demand reports using some crappy third party software, and will eventually try to build a data warehouse using more of the same crappy third party software (name removed to protect the guilty, don't ask I will not tell). The rationale for this was that we didn't want to spend more money to buy this additional software from Microsoft (this was not my decision, I had no input, but is my problem now). But from what I can tell is that Enterprise includes all of these tools, or am I missing something? What comes bundled with SQL Server 2005 Enterprise as far as reporting and data warehousing? Will we need to purchase anything else? is there actually anything else that can be purchased from Microsoft in this regard?

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• Stored Procedure Does Not Fire Last Command

  - by jp2code

  On our SQL Server (Version 10.0.1600), I have a stored procedure that I wrote. It is not throwing any errors, and it is returning the correct values after making the insert in the database. However, the last command spSendEventNotificationEmail (which sends out email notifications) is not being run. I can run the spSendEventNotificationEmail script manually using the same data, and the notifications show up, so I know it works. Is there something wrong with how I call it in my stored procedure? [dbo].[spUpdateRequest](@packetID int, @statusID int output, @empID int, @mtf nVarChar(50)) AS BEGIN -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SET NOCOUNT ON; DECLARE @id int SET @id=-1 -- Insert statements for procedure here SELECT A.ID, PacketID, StatusID INTO #act FROM Action A JOIN Request R ON (R.ID=A.RequestID) WHERE (PacketID=@packetID) AND (StatusID=@statusID) IF ((SELECT COUNT(ID) FROM #act)=0) BEGIN -- this statusID has not been entered. Continue SELECT ID, MTF INTO #req FROM Request WHERE PacketID=@packetID WHILE (0 < (SELECT COUNT(ID) FROM #req)) BEGIN SELECT TOP 1 @id=ID FROM #req INSERT INTO Action (RequestID, StatusID, EmpID, DateStamp) VALUES (@id, @statusID, @empID, GETDATE()) IF ((@mtf IS NOT NULL) AND (0 < LEN(RTRIM(@mtf)))) BEGIN UPDATE Request SET MTF=@mtf WHERE ID=@id END DELETE #req WHERE ID=@id END DROP TABLE #req SELECT @id=@@IDENTITY, @statusID=StatusID FROM Action SELECT TOP 1 @statusID=ID FROM Status WHERE (@statusID<ID) AND (-1 < Sequence) EXEC spSendEventNotificationEmail @packetID, @statusID, 'http:\\cpweb:8100\NextStep.aspx' END ELSE BEGIN SET @statusID = -1 END DROP TABLE #act END Idea of how the data tables are connected:

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• how to model a follower stream in appengine?

  - by molicule

  I am trying to design tables to buildout a follower relationship. Say I have a stream of 140char records that have user, hashtag and other text. Users follow other users, and can also follow hashtags. I am outlining the way I've designed this below, but there are two limitaions in my design. I was wondering if others had smarter ways to accomplish the same goal. The issues with this are The list of followers is copied in for each record If a new follower is added or one removed, 'all' the records have to be updated. The code class HashtagFollowers(db.Model): """ This table contains the followers for each hashtag """ hashtag = db.StringProperty() followers = db.StringListProperty() class UserFollowers(db.Model): """ This table contains the followers for each user """ username = db.StringProperty() followers = db.StringListProperty() class stream(db.Model): """ This table contains the data stream """ username = db.StringProperty() hashtag = db.StringProperty() text = db.TextProperty() def save(self): """ On each save all the followers for each hashtag and user are added into a another table with this record as the parent """ super(stream, self).save() hfs = HashtagFollowers.all().filter("hashtag =", self.hashtag).fetch(10) for hf in hfs: sh = streamHashtags(parent=self, followers=hf.followers) sh.save() ufs = UserFollowers.all().filter("username =", self.username).fetch(10) for uf in ufs: uh = streamUsers(parent=self, followers=uf.followers) uh.save() class streamHashtags(db.Model): """ The stream record is the parent of this record """ followers = db.StringListProperty() class streamUsers(db.Model): """ The stream record is the parent of this record """ followers = db.StringListProperty() Now, to get the stream of followed hastags indexes = db.GqlQuery("""SELECT __key__ from streamHashtags where followers = 'myusername'""") keys = [k,parent() for k in indexes[offset:numresults]] return db.get(keys) Is there a smarter way to do this?

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• ASP.NET MVC Membership, Get new UserID

  - by Vishal Bharakhda

  I am trying to register a new user and also understand how to get the new userID so i can start creating my own user tables with a userID mapping to the asp.net membership user table. Below is my code: [AcceptVerbs(HttpVerbs.Post)] public ActionResult Register(string userName, string email, string position, string password, string confirmPassword) { ViewData["PasswordLength"] = MembershipService.MinPasswordLength; ViewData["position"] = new SelectList(GetDeveloperPositionList()); if (ValidateRegistration(userName, email, position, password, confirmPassword)) { // Attempt to register the user MembershipCreateStatus createStatus = MembershipService.CreateUser(userName, password, email); if (createStatus == MembershipCreateStatus.Success) { FormsAuth.SignIn(userName, false /* createPersistentCookie */); return RedirectToAction("Index", "Home"); } else { ModelState.AddModelError("_FORM", ErrorCodeToString(createStatus)); } } // If we got this far, something failed, redisplay form return View(); } I've done some research and many sites inform me to use Membership.GetUser().ProviderUserKey; but this throws an error as Membership is NULL. I placed this line of code just above "return RedirectToAction("Index", "Home");" within the if statement. Please can someone advise me on this... Thanks in advance

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• Using Subsonic 3.0 Advanced Templates

  - by umit

  Hi all, I've been trying to use Subsonic Advanced Templates in a project for a while but most of the time I find myself writing a Stored Procedure as I can't find a proper way of doing it in code. Subsonic created corresponding objects for my DB tables and for foreign keys it created IQueryable fields inside each object. These fields are not loaded by default and a new SQL query is executed when you access them. 1- Is there a way to get all data in one query (deep load)? Also these fields can not be assigned. So when I want to create an object in a maintenance page, I can't put all the data into this object before saving it in DB: Post post = new Post(); //get photos for this post IList<PostPhoto> postPhotos = GetPostPhotos(); post.PostPhotos = postPhotos; 2- Is it possible to have one Post object with all fields set from user input? Think of the Post object above and assume I've successfully assigned its fields. Now I need to save it to the DB. 3- Is using BatchQuery the only way to do it in one query? If I have 4 photos in PostPhotos field; 2 of them previously saved and 2 of them new, can I use the Update method to handle both the adding and updating of these photos? Any ideas or links are appreciated. Cheers...

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• Update SQL Server 2000 to SQL Server 2008: Benefits please?

  - by Ciaran Archer

  Hi there I'm looking for the benefits of upgrading from SQL Server 2000 to 2008. I was wondering: What database features can we leverage with 2008 that we can't now? What new TSQL features can we look forward to using? What performance benefits can we expect to see? What else will make management go for it? And the converse: What problems can we expect to encounter? What other problems have people found when migrating? Why fix something that isn't (technically) broken? We work in a Java shop, so any .NET / CLR stuff won't rock our world. We also use Eclipse as our main development so any integration with Visual Studio won't be a plus. We do use SQL Server Management Studio however. Some background: Our main database machine is a 32bit Dell Intel Xeon MP CPU 2.0GHz, 40MB of RAM with Physical Address Extension running Windows Server 2003 Enterprise Edition. We will not be changing our hardware. Our databases in total are under a TB with some having more than 200 tables. But they are busy and during busy times we see 60-80% CPU utilisation. Apart form the fact that SQL Server 2000 is coming close to end of life, why should we upgrade? Any and all contributions are appreciated!

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• Cursor returns zero rows from query to table

  - by brockoli

  I've created an SQLiteDatabase in my app and populated it with some data. I can connect to my AVD with a terminal and when I issue select * from articles; I get a list of all the rows in my table and everything looks fine. However, in my code when I query my table, I get a cursor back that has my tables columns, but zero rows of data. Here is my code.. mDbHelper.open(); Cursor articles = mDbHelper.fetchAllArticles(); startManagingCursor(articles); Cursor feeds = mDbHelper.fetchAllFeeds(); startManagingCursor(feeds); mDbHelper.close(); int titleColumn = articles.getColumnIndex("title"); int feedIdColumn = articles.getColumnIndex("feed_id"); int feedTitleColumn = feeds.getColumnIndex("title"); /* Check if our result was valid. */ if (articles != null) { int count = articles.getCount(); /* Check if at least one Result was returned. */ if (articles.moveToFirst()) { In the above code, my Cursor articles returns with my 4 columns, but when I call getCount() it returns zero, even though I can see hundreds of rows of data in that table from command line. Any idea what I might be doing wrong here? Also.. here is my code for fetchAllArticles.. public Cursor fetchAllArticles() { return mDb.query(ARTICLES_TABLE, new String[] {ARTICLE_KEY_ROWID, ARTICLE_KEY_FEED_ID, ARTICLE_KEY_TITLE, ARTICLE_KEY_URL}, null, null, null, null, null); } Rob W.

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• Could DataGridView be this dumb? or its me?lol

  - by Selase

  Am trying to bind data to a dropdown list on pageload based on a condition. Code explains further below. public partial class AddExhibit : System.Web.UI.Page { string adminID, caseIDRetrieved; DataSet caseDataSet = new DataSet(); SqlDataAdapter caseSqlDataAdapter = new SqlDataAdapter(); string strConn = WebConfigurationManager.ConnectionStrings["CMSSQL3ConnectionString1"].ConnectionString; protected void Page_Load(object sender, EventArgs e) { adminID = Request.QueryString["adminID"]; caseIDRetrieved = Request.QueryString["caseID"]; if (caseIDRetrieved != null) { CaseIDDropDownList.Text = caseIDRetrieved; //CaseIDDropDownList.Enabled = false; } else { try { CreateDataSet(); DataView caseDataView = new DataView(caseDataSet.Tables[0]); CaseIDDropDownList.DataSource = caseDataView; CaseIDDropDownList.DataBind(); } catch (Exception ex) { string script = "<script>alert('" + ex.Message + "');</script>"; } } } The CreateDataset method that is called in the if..else statement is contains the following code. private void CreateDataSet() { SqlConnection caseConnection = new SqlConnection(strConn); caseSqlDataAdapter.SelectCommand = new SqlCommand("Select CaseID FROM Cases", caseConnection); caseSqlDataAdapter.Fill(caseDataSet); } However when i load the page and as usual the condition that is supposed to bid the data is met, the gridview decides to displays as follows... IS IT ME OR ITS THE DATAGRID?...??

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• SQL Duplicates Issue SQL SERVER 2000

  - by jeff

  I have two tables : Product and ProductRateDetail. The parent table is Product. I have duplicate records in the product table which need to be unique. There are entries in the ProductRateDetail table which correspond to duplicate records in the product table. Somehow I need to update the ProductRateDetail table to match the original (older) ID from the Product table and then remove the duplicates from the product table. I would do this manually but there are 100's of records. i.e. something like UPDATE tbl_productRateDetail SET productID = (originalID from tbl_product) then something like DELETE from tbl_product WHERE duplicate ID and only delete the recently added ID data example: (sorry can't work out this formatting thing) tbl_Product select * from dbo.Product where ProductCode = '10003' ProductID ProductTypeID ProductDescription ProductCode ProductSize 365 1 BEND DOUBLE FLANGED 10003 80mmX90deg 1354 1 BEND DOUBLE FLANGED 10003 80mmX90deg tbl_ProductRateDetail SELECT * FROM [MSTS2].[dbo].[ProductRateDetail] WHERE ProductID in (365,1354) ProductRateDetailID ProductRateID ProductID UnitRate 365 1 365 16.87 1032 5 365 16.87 2187 10 365 16.87 2689 11 365 16.87 3191 12 365 16.87 7354 21 1354 21.30 7917 22 1354 21.30 8480 23 1354 21.30 9328 25 1354 21.30 9890 26 1354 21.30 10452 27 1354 21.30 Please help!

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• Getting random record from database with group by

  - by Saif Bechan

  Hello i have a question on picking random entries from a database. I have 4 tables, products, bids and autobids, and users. Products ------- id 20,21,22,23,24(prime_key) price........... etc........... users ------- id(prim_key) name user1,user2,user3 etc bids ------- product_id user_id created autobids -------- user_id product_id Now a multiple users can have an autobid on an product. So for the next bidder I want to select a random user from the autobid table example of the query in language: for each product in the autobid table I want a random user, which is not the last bidder. On product 20 has user1,user2,user3 an autobidding. On product 21 has user1,user2,user3 an autobidding Then I want a resultset that looks for example like this 20 – user2 21 – user3 Just a random user. I tried miximg the GOUP BY (product_id) and making it RAND(), but I just can't get the right values from it. Now I am getting a random user, but all the values that go with it don't match. Can someone please help me construct this query, I am using php and mysql

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• Getting a certain node using DataSet

  - by MarceloRamires

  I have the following XML <xml> <ObsCont xCampo="field1"> <xTexto>example1</xTexto> </ObsCont> <ObsCont xCampo="field2"> <xTexto>example2</xTexto> </ObsCont> <ObsCont xCampo="field3"> <xTexto>example3</xTexto> </ObsCont> <field>information</field> </xml> Is there a way to get the content of "xTexto" inside the ObsCont that has "field2" value for the attribute xCampo using DataSet ? It would be desireable to have a single liner like the following: DataSet ds = new DataSet(); ds.ReadXml(StrArquivoProc); ds.Tables["xml"].Rows[0]["field"].ToString(); //field == "information" If I use the same method I'm not specifying that I want the one with the desired attribute.

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• multi-shop orders table and sequential order numbers based on shop

  - by imanc

  Hey, I am looking at building a shop solution that needs to be scalable. Currently it retrieves 1-2000 orders on average per day across multiple country based shops (e.g. uk, us, de, dk, es etc.) but this order could be 10x this amount in two years. I am looking at either using separate country-shop databases to store the orders tables, or looking to combine all into one order table. If all orders exist in one table with a global ID (auto num) and country ID (e.g uk,de,dk etc.), each countries orders would also need to have sequential ordering. So in essence, we'd have to have a global ID and a country order ID, with the country order ID being sequential for countries only, e.g. global ID = 1000, country = UK, country order ID = 1000 global ID = 1001, country = DE, country order ID = 1000 global ID = 1002, country = DE, country order ID = 1001 global ID = 1003, country = DE, country order ID = 1002 global ID = 1004, country = UK, country order ID = 1001 THe global ID would be DB generated and not something I would need to worry about. But I am thinking that I'd have to do a query to get the current country order based ID+1 to find the next sequential number. Two things concern me about this: 1) query times when the table has potentially millions of rows of data and I'm doing a read before a write, 2) the potential for ID number clashes due to simultaneous writes/reads. With a MyISAM table the entire table could be locked whilst the last country order + 1 is retrieved, to prevent ID number clashes. I am wondering if anyone knows of a more elegant solution? Cheers, imanc

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• Setting up relations/mappings for a SQLAlchemy many-to-many database

  - by Brent Ramerth

  I'm new to SQLAlchemy and relational databases, and I'm trying to set up a model for an annotated lexicon. I want to support an arbitrary number of key-value annotations for the words which can be added or removed at runtime. Since there will be a lot of repetition in the names of the keys, I don't want to use this solution directly, although the code is similar. My design has word objects and property objects. The words and properties are stored in separate tables with a property_values table that links the two. Here's the code: from sqlalchemy import Column, Integer, String, Table, create_engine from sqlalchemy import MetaData, ForeignKey from sqlalchemy.orm import relation, mapper, sessionmaker from sqlalchemy.ext.declarative import declarative_base engine = create_engine('sqlite:///test.db', echo=True) meta = MetaData(bind=engine) property_values = Table('property_values', meta, Column('word_id', Integer, ForeignKey('words.id')), Column('property_id', Integer, ForeignKey('properties.id')), Column('value', String(20)) ) words = Table('words', meta, Column('id', Integer, primary_key=True), Column('name', String(20)), Column('freq', Integer) ) properties = Table('properties', meta, Column('id', Integer, primary_key=True), Column('name', String(20), nullable=False, unique=True) ) meta.create_all() class Word(object): def __init__(self, name, freq=1): self.name = name self.freq = freq class Property(object): def __init__(self, name): self.name = name mapper(Property, properties) Now I'd like to be able to do the following: Session = sessionmaker(bind=engine) s = Session() word = Word('foo', 42) word['bar'] = 'yes' # or word.bar = 'yes' ? s.add(word) s.commit() Ideally this should add 1|foo|42 to the words table, add 1|bar to the properties table, and add 1|1|yes to the property_values table. However, I don't have the right mappings and relations in place to make this happen. I get the sense from reading the documentation at http://www.sqlalchemy.org/docs/05/mappers.html#association-pattern that I want to use an association proxy or something of that sort here, but the syntax is unclear to me. I experimented with this: mapper(Word, words, properties={ 'properties': relation(Property, secondary=property_values) }) but this mapper only fills in the foreign key values, and I need to fill in the other value as well. Any assistance would be greatly appreciated.

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• Extract data from PostgreSQL DB without using pg_dump

  - by John Horton

  There is a PostgreSQL database on which I only have limited access (e.g, I can't use pg_dump). I am trying to create a local "mirror" by exporting certain tables from the database. I do not have the permissions needed to just dump a table as SQL from within psql. Right now, I just have a Python script that iterates through my table_names, selects all fields and then exports them as a CSV: for table_name, file_name in zip(table_names, file_names): cmd = """echo "\\\copy (select * from %s)" to stdout WITH CSV HEADER | psql -d remote_db | gzip > ./%s/%s.gz"""%(table_name,dir_name,file_name) os.system(cmd) I would like to not use CSV if possible, as I lose the field types and the encoding can get messed up. First best would probably be some way of getting the generating SQL code for the table using \copy. Next best would be XML, ideally with some way of preserving the field types. If that doesn't work, I think the final option might be two queries---one to get the field data types, the other to get the actual data. Any thoughts or advice would be greatly appreciated - thanks!

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• How to create XSD schema from XML with this kind of structure (in .net)?

  - by Mr. Brownstone

  Here's the problem: my input is XML file that looks something like: <BaseEntityClassInfo> <item> <key>BaseEntityClassInfo.SomeField</key> <value>valueData1</value> </item> <item> <key>BaseEntityClassInfo.AdditionalDataClass.SomeOtherField</key> <value>valueData2</value> </item> <item> <key>BaseEntityClassInfo.AdditionalDataClass.AnotherClassInfo.DisplayedText</key> <value>valueData3</value> </item> ... ... </BaseEntityClassInfo> The <key> element somehow describes entity classes fields and relationships (used in some other app that I don't have access to) and the <value> stores the actual data that I need. My goal is to programatically generate a typed Dataset from this XML that could then be used for creating reports. I thought of building some XSD schema from input XML file first and then use this schema to generate Dataset but I'm not sure how to do that. The problem is that I don't want all data in one table, I need several tables with relationships based on the <key> value so I guess I need to infer relational structure from XML <key> data in some way. So what do you think? How could this be done and what would be the best approach? Any advice, ideas, suggestions would be appreciated!

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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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• No Buffer Space available(maximum connection reached?) Form Postgres EDB Driver

  - by Listening.Platform

  We are facing an exception while connecting to database through our java application. The stack trace is as follows com.edb.util.PSQLException: The connection attempt failed. at com.edb.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:189) at com.edb.core.ConnectionFactory.openConnection(ConnectionFactory.java:64) at com.edb.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:161) at com.edb.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:30) at com.edb.jdbc3.Jdbc3Connection.<init>(Jdbc3Connection.java:24) at com.edb.Driver.makeConnection(Driver.java:391) at com.edb.Driver.connect(Driver.java:266) at java.sql.DriverManager.getConnection(Unknown Source) at java.sql.DriverManager.getConnection(Unknown Source) ... 12 more Caused by: java.net.SocketException: No buffer space available (maximum connections reached?): connect at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.PlainSocketImpl.doConnect(Unknown Source) at java.net.PlainSocketImpl.connectToAddress(Unknown Source) at java.net.PlainSocketImpl.connect(Unknown Source) at java.net.SocksSocketImpl.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at java.net.Socket.connect(Unknown Source) at java.net.Socket.<init>(Unknown Source) at java.net.Socket.<init>(Unknown Source) at com.edb.core.PGStream.<init>(PGStream.java:70) at com.edb.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:115) ... 20 more When the error occured we were not able to connect to internet and DB and had to reboot the system. But the error occured again after 3 days at same code i.e while connecting to DB. We checked TCP connections using netstat. But there were not many TCP connections i.e it has not reached the max limit. Our application has multiple long running Java processes that pools the DB connections (not more than 60) and keeps it alive for firing the next query (as it has to poll the DB every 2 seconds). Some of the queries in our application are joining large tables (10 million records) to get the related data. We are using following System and applications Windows 2003 server SP2 Java 1.6 Postgres Plus Advanced server 8.4 Database edb-jdbc14.jar driver for connection DB from Java We have used the default configuration of Postgres DB except increasing the connection to 120 from 100. Has anybody encountred the same error with postgres edb driver? Can anybody help us finding the solution?

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• getting hasMany records of a HABTM relationship

  - by charliefarley321

  I have tables: categories HABTM sculptures hasMany images from the CategoriesController#find() produces an array like so: array( 'Category' => array( 'id' => '3', 'name' => 'Modern', ), 'Sculpture' => array( (int) 0 => array( 'id' => '25', 'name' => 'Ami', 'material' => 'Bronze', 'CategoriesSculpture' => array( 'id' => '18', 'category_id' => '3', 'sculpture_id' => '25' ) ), (int) 1 => array( 'id' => '26', 'name' => 'Charis', 'material' => 'Bronze', 'CategoriesSculpture' => array( 'id' => '19', 'category_id' => '3', 'sculpture_id' => '26' ) ) ) ) I'd like to be able to get the images related to sculpture in the array as well if this is possible?

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• Ways to update a dependent table in the same MySQL transaction?

  - by codie

  I need to update two tables inside a single transaction. The individual queries look something like this: 1. INSERT INTO t1 (col1, col2) VALUES (val1, val2) ON DUPLICATE KEY UPDATE col2 = val2; If the above query causes an insert then I need to run the following statement on the second table: 2. INSERT INTO t2 (col1, col2) VALUES (val1, val2) ON DUPLICATE KEY UPDATE col2 = col2 + val2; otherwise, 3. UPDATE t2 SET col2 = col2 - old_val2 + val2 WHERE col1 = val1; -- old_val2 is the value of t1.col2 before it was updated Right now I run a SELECT on t1 first, to determine whether statement 1 will cause an insert or update on t1. Then I run statement 1 and either of 2 and 3 inside a transaction. What are the ways in which I can do all of these inside one transaction itself? The approach I was thinking of is the following: UPDATE t2, t1 set t2.col2 = t2.col2 - t1.col2 WHERE t1.col1 = t2.col2 and t1.col1 = val1; INSERT INTO t1 (col1, col2) VALUES (val1, val2) ON DUPLICATE KEY UPDATE col2 = val2; INSERT INTO t2, t1 (t2.col1, t2.col2) VALUES (t1.col1, t1.col2) ON DUPLICATE KEY UPDATE t2.col2 = t2.col2 + t1.col2 WHERE t1.col1 = t2.col2 and t1.col1 = val1; Unfortunately, there's no multi-table INSERT... ON DUPLICATE KEY UPDATE in MySQL 5.0. What else could I do?

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