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  • C# - Rollback SqlTransaction in catch block - Problem with object accessability

    - by Marks
    Hi there. I've got a problem, and all articles or examples i found seem to not care about it. I want to do some database actions in a transaction. What i want to do is very similar to most examples: using (SqlConnection Conn = new SqlConnection(_ConnectionString)) { try { Conn.Open(); SqlTransaction Trans = Conn.BeginTransaction(); using (SqlCommand Com = new SqlCommand(ComText, Conn)) { /* DB work */ } } catch (Exception Ex) { Trans.Rollback(); return -1; } } But the problem is, that the SqlTransaction Trans is declared inside the try block. So it is not accessable in the catch() block. Most examples just do Conn.Open() and Conn.BeginTransaction() before the try block. But i think thats a bit risky, since both can throw multiple exceptions. Am I wrong, or do most people just ignore this risk? Whats the best solution to be able to rollback, if an exception happens. Thanks in advance, Marks

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  • MySQL Delete from 1 table, using multiple tables

    - by nute
    I would like to delete all the rows found by that query: SELECT cart_abandon.* FROM cart_abandon, cart_product, txn_product, users WHERE cart_abandon.cartid = cart_product.cartid AND cart_product.productid = txn_product.productid AND txn_product.username = users.username AND users.id = cart_abandon.userid AND txn_product.txndate >= cart_abandon.abandondate The thing to keep in mind is that the query here uses 4 different tables, however I only want to delete rows from 1 table (cart_abandon). Is there an easy way to do that? Maybe this: ? DELETE cart_abandon FROM cart_abandon, cart_product, txn_product, users WHERE cart_abandon.cartid = cart_product.cartid AND cart_product.productid = txn_product.productid AND txn_product.username = users.username AND users.id = cart_abandon.userid AND txn_product.txndate >= cart_abandon.abandondate Is that valid? Correct?

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  • Multi-tier applications using L2S, WCF and Base Class

    - by Gena Verdel
    Hi all. One day I decided to build this nice multi-tier application using L2S and WCF. The simplified model is : DataBase-L2S-Wrapper(DTO)-Client Application. The communication between Client and Database is achieved by using Data Transfer Objects which contain entity objects as their properties. abstract public class BaseObject { public virtual IccSystem.iccObjectTypes ObjectICC_Type { get { return IccSystem.iccObjectTypes.unknownType; } } [global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_ID", AutoSync = AutoSync.OnInsert, DbType = "BigInt NOT NULL IDENTITY", IsPrimaryKey = true, IsDbGenerated = true)] [global::System.Runtime.Serialization.DataMemberAttribute(Order = 1)] public virtual long ID { //get; //set; get { return _ID; } set { _ID = value; } } } [DataContract] public class BaseObjectWrapper<T> where T : BaseObject { #region Fields private T _DBObject; #endregion #region Properties [DataMember] public T Entity { get { return _DBObject; } set { _DBObject = value; } } #endregion } Pretty simple, isn't it?. Here's the catch. Each one of the mapped classes contains ID property itself so I decided to override it like this [global::System.Data.Linq.Mapping.TableAttribute(Name="dbo.Divisions")] [global::System.Runtime.Serialization.DataContractAttribute()] public partial class Division : INotifyPropertyChanging, INotifyPropertyChanged { [global::System.Data.Linq.Mapping.ColumnAttribute(Storage="_ID", AutoSync=AutoSync.OnInsert, DbType="BigInt NOT NULL IDENTITY", IsPrimaryKey=true, IsDbGenerated=true)] [global::System.Runtime.Serialization.DataMemberAttribute(Order=1)] public override long ID { get { return this._ID; } set { if ((this._ID != value)) { this.OnIDChanging(value); this.SendPropertyChanging(); this._ID = value; this.SendPropertyChanged("ID"); this.OnIDChanged(); } } } } Wrapper for division is pretty straightforward as well: public class DivisionWrapper : BaseObjectWrapper<Division> { } It worked pretty well as long as I kept ID values at mapped class and its BaseObject class the same(that's not very good approach, I know, but still) but then this happened: private CentralDC _dc; public bool UpdateDivision(ref DivisionWrapper division) { DivisionWrapper tempWrapper = division; if (division.Entity == null) { return false; } try { Table<Division> table = _dc.Divisions; var q = table.Where(o => o.ID == tempWrapper.Entity.ID); if (q.Count() == 0) { division.Entity._errorMessage = "Unable to locate entity with id " + division.Entity.ID.ToString(); return false; } var realEntity = q.First(); realEntity = division.Entity; _dc.SubmitChanges(); return true; } catch (Exception ex) { division.Entity._errorMessage = ex.Message; return false; } } When trying to enumerate over the in-memory query the following exception occurred: Class member BaseObject.ID is unmapped. Although I'm stating the type and overriding the ID property L2S fails to work. Any suggestions?

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  • Using a comma seperated data in MYSQL "IN" clause

    - by Sashi Kant
    I have a column in one of my table where I store multiple ids seperated by comma's. Is there a way in which I can use this column's value in the "IN" clause of a query. The column(city) has values like 6,7,8,16,21,2 I need to use as Select * from table where e_ID in (Select city from locations where e_Id=?) I am satisfied with Crozin's answer, but I am open to suggestions, views and options. Feel free to share your views.

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  • how to increase the limit of exceptions in oracle

    - by Arunachalam
    how to increase the limit of exceptions in oracle ? i have a excel sheet in which their are about 900 records to be appended .so i converted the excel to dat file and wrote a batch file that read from the dat file and appends it to the concern table but the batch file stop execution once the exceptions reach 51(all integrity constrain parent key not found) so the remaining valid files are not updated .its very difficult to find which record has integrity constrain is there a way to increase this exception limit ?

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  • How to join nearly identical several queries into one?

    - by Devyn
    Hi, Assume I have an order_dummy table where order_dummy_id, order_id, user_id, book_id, author_id are stored. You may complain the logic of my table but I somehow need to do it that way. I want to execute following queries. SELECT * FROM order_dummy WHERE order_id = 1 AND user_id = 1 AND book_id = 1 ORDER BY `order_dummy_id` DESC LIMIT 1 SELECT * FROM order_dummy WHERE order_id = 1 AND user_id = 1 AND book_id = 2 ORDER BY `order_dummy_id` DESC LIMIT 1 SELECT * FROM order_dummy WHERE order_id = 1 AND user_id = 1 AND book_id = 3 ORDER BY `order_dummy_id` DESC LIMIT 1 Please keep in mind that several numbers of same book is included in one order. Therefore, I list order_dummy_id by descending and limit 1 so only LATEST ORDER of A BOOK is shown. But my goal is to show other books in that way in one table. I used group by like this ... SELECT * FROM order_dummy WHERE order_id = 1 AND user_id = 1 GROUP BY book_id but it only shows order_dummy_id with ascending result. I have no idea anymore. Looking forward your kindness help!

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  • Django: Determining if a user has voted or not

    - by TheLizardKing
    I have a long list of links that I spit out using the below code, total votes, submitted by, the usual stuff but I am not 100% on how to determine if the currently logged in user has voted on a link or not. I know how to do this from within my view but do I need to alter my below view code or can I make use of the way templates work to determine it? I have read http://stackoverflow.com/questions/1528583/django-vote-up-down-method but I don't quite understand what's going on ( and don't need any ofjavascriptery). Models (snippet): class Link(models.Model): category = models.ForeignKey(Category, blank=False, default=1) user = models.ForeignKey(User) created = models.DateTimeField(auto_now_add=True) modified = models.DateTimeField(auto_now=True) url = models.URLField(max_length=1024, unique=True, verify_exists=True) name = models.CharField(max_length=512) def __unicode__(self): return u'%s (%s)' % (self.name, self.url) class Vote(models.Model): link = models.ForeignKey(Link) user = models.ForeignKey(User) created = models.DateTimeField(auto_now_add=True) def __unicode__(self): return u'%s vote for %s' % (self.user, self.link) Views (snippet): def hot(request): links = Link.objects.select_related().annotate(votes=Count('vote')).order_by('-created') for link in links: delta_in_hours = (int(datetime.now().strftime("%s")) - int(link.created.strftime("%s"))) / 3600 link.popularity = ((link.votes - 1) / (delta_in_hours + 2)**1.5) if request.user.is_authenticated(): try: link.voted = Vote.objects.get(link=link, user=request.user) except Vote.DoesNotExist: link.voted = None links = sorted(links, key=lambda x: x.popularity, reverse=True) links = paginate(request, links, 15) return direct_to_template( request, template = 'links/link_list.html', extra_context = { 'links': links, }) The above view actually accomplishes what I need but in what I believe to be a horribly inefficient way. This causes the dreaded n+1 queries, as it stands that's 33 queries for a page containing just 29 links while originally I got away with just 4 queries. I would really prefer to do this using Django's ORM or at least .extra(). Any advice?

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  • What is the equivalent of REGEXP_SUBSTR in mysql?

    - by KandadaBoggu
    I want to extract a word from a string column of a table. description =========================== abc order_id: 2 xxxx yyy aa mmm order_id: 3 nn kk yw Expected result set order_id =========================== 2 3 Table will at most have 100 rows, text length is ~256 char and column always has one order_id present. So performance is not an issue. In Oracle, I can use REGEXP_SUBSTR for this problem. How would I solve this in MySQL?

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  • (mySQL) Unable to query 2 tables properly for data

    - by Devner
    I have 2 tables. One is 'page_links' and the other is 'rpp'. Table page_links is the superset of table rpp. The following is the schema of my tables: -- Table structure for table `page_links` -- CREATE TABLE IF NOT EXISTS `page_links` ( `page` varchar(255) NOT NULL, `page_link` varchar(100) NOT NULL, `heading_id` tinyint(3) unsigned NOT NULL, PRIMARY KEY (`page`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; -- -- Dumping data for table `page_links` -- INSERT INTO `page_links` (`page`, `page_link`, `heading_id`) VALUES ('a1.php', 'A1', 8), ('b1.php', 'B1', 8), ('c1.php', 'C1', 5), ('d1.php', 'D1', 5), ('e1.php', 'E1', 8), ('f1.php', 'F1', 8), ('g1.php', 'G1', 8), ('h1.php', 'H1', 1), ('i1.php', 'I1', 1), ('j1.php', 'J1', 8), ('k1.php', 'K1', 8), ('l1.php', 'L1', 8), ('m1.php', 'M1', 8), ('n1.php', 'N1', 8), ('o1.php', 'O1', 8), ('p1.php', 'P1', 4), ('q1.php', 'Q1', 5), ('r1.php', 'R1', 4); -- Table structure for table `rpp` -- CREATE TABLE IF NOT EXISTS `rpp` ( `role_id` tinyint(3) unsigned NOT NULL, `page` varchar(255) NOT NULL, `is_allowed` tinyint(1) NOT NULL, PRIMARY KEY (`role_id`,`page`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; -- -- Dumping data for table `rpp` -- INSERT INTO `rpp` (`role_id`, `page`, `is_allowed`) VALUES (3, 'a1.php', 1), (3, 'b1.php', 1), (3, 'c1.php', 1), (3, 'd1.php', 1), (3, 'e1.php', 1), (3, 'f1.php', 1), (3, 'h1.php', 1), (3, 'i1.php', 1), (3, 'l1.php', 1), (3, 'm1.php', 1), (3, 'n1.php', 1), (4, 'a1.php', 1), (4, 'b1.php', 1), (4, 'q1.php', 1), (5, 'r1.php', 1); WHAT I AM TRYING TO DO: I am trying to query both the above tables (in a single query) in such a way that all the pages from page_links are displayed along with the is_allowed value from rpp for a particular role. For example, I want to get the is_allowed value of all the pages from rpp for role_id = 3 and at the same time, list all the available pages from page_links. A clear example of my expected result would be: page is_allowed role_id ---------------------------------------- a1.php 1 3 b1.php 1 3 c1.php 1 3 d1.php 1 3 e1.php 1 3 f1.php 1 3 g1.php NULL NULL h1.php 1 3 i1.php 1 3 j1.php NULL NULL k1.php NULL NULL l1.php 1 3 m1.php 1 3 n1.php 1 3 o1.php NULL NULL p1.php NULL NULL q1.php NULL NULL r1.php NULL NULL One more example of my desired result could be achieved by doing a LEFT JOIN rpp ON page_links.page = rpp.page but we need to omit using role_id = 3 (or any value) to be able to get that. But I do want to specify the role_id as well and get the results. I need the query to be able to get this result. I would appreciate any replies that could help me with this. If you can suggest me any changes as well to the table(s) design to be able to achieve the desired result, that's good as well. Thanks in advance.

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  • Get column of a mysql entry

    - by Xelluloid
    Is there a possibility to get the name of the column a database entry belongs to? Perhaps I have three columns with column names col1, col2 and col3. Now I want to select for every column the column with the maximum entry, something like this. Select name_of_column(max(col1,col2,col3)). I know that I can ask for the name of the columns by its ordinal position in the information_schema.COLUMNS table but how do I get the ordinal position of a database entry within a table?

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  • How can I do more than one level of cascading deletes in Linq?

    - by Gary McGill
    If I have a Customers table linked to an Orders table, and I want to delete a customer and its corresponding orders, then I can do: dataContext.Orders.DeleteAllOnSubmit(customer.Orders); dataContext.Customers.DeleteOnSubmit(customer); ...which is great. However, what if I also have an OrderItems table, and I want to delete the order items for each of the orders deleted? I can see how I could use DeleteAllOnSubmit to cause the deletion of all the order items for a single order, but how can I do it for all the orders?

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  • Oracle query to select rows with unique code

    - by Jasim
    I have a table like this C1 C2 C3 Code 1 2 3 33 1 2 3 34 2 4 1 14 1 2 3 14 i want to select only those record whose code is appearing only in single row. ie, in this case rows with code 33 and 34.. as they appear only once in this table. How can i write a query for that

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  • Moving from NHibernate to FluentNHibernate: assembly error (related to versions)?

    - by goober
    Not sure where to start, but I had gotten the most recent version of NHibernate, successfully mapped the most simple of business objects, etc. When trying to move to FluentNHibernate and do the same thing, I got this error message on build: "System.IO.FileLoadException: Could not load file or assembly 'NHibernate, Version=2.1.0.4000, Culture=neutral, PublicKeyToken=aa95f207798dfdb4' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference." Background: I'm new to Hibernate, NHibernate, and FluentNHibernate -- but not to .NET, C#, etc. Database I have a database table called Category: (PK) CategoryID (type: int), unique, auto-incrementing UserID (type: uniqueidentifier) -- given the value of the user Guid in ASP.NET database Title (type: varchar(50) -- the title of the category Components involved: I have a SessionProviderClass which creates the mapping to the database I have a Category class which has all the virtual methods for FluentNHibernate to override I have a CategoryMap : ClassMap class, which does the fluent mappings for the entity I have a CategoryRepository class that contains the method to add & save the category I have the TestCatAdd.aspx file which uses the CategoryRepository class. Would be happy to post code for any of those, but I'm not sure that it's necessary, as I think the issue is that somewhere there's a version conflict between what FluentNHibernate references and the NHibernate I have installed from before. Thanks in advance for any help you can give!

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  • Converting MySQL Resultset from Rows to Columns

    - by gms8994
    I have output from a select like this: 04:47:37> select * from attributes left outer join trailer_attributes on attributes.id = trailer_attributes.attribute_id; +----+--------------+----------+-----------+------------+--------------+-----------------+ | id | name | datatype | list_page | trailer_id | attribute_id | attribute_value | +----+--------------+----------+-----------+------------+--------------+-----------------+ | 1 | Make | text | 1 | 1 | 1 | Apple | | 1 | Make | text | 1 | 2 | 1 | sdfg | | 2 | Year | number | 1 | 1 | 2 | 2009 | | 2 | Year | number | 1 | 2 | 2 | sdfg | | 3 | Type | text | 0 | 1 | 3 | iPhone | | 3 | Type | text | 0 | 2 | 3 | sdfg | | 4 | Axles | text | 0 | 1 | 4 | asdf | | 4 | Axles | text | 0 | 2 | 4 | sdfg | | 7 | Size | text | 0 | 1 | 7 | asd1 | | 7 | Size | text | 0 | 2 | 7 | sdfg | | 8 | Frame | text | 0 | 1 | 8 | | | 8 | Frame | text | 0 | 2 | 8 | sdfg | | 9 | Height | text | 0 | 1 | 9 | | | 9 | Height | text | 0 | 2 | 9 | sdfg | | 10 | Dollies | text | 0 | 1 | 10 | | | 10 | Dollies | text | 0 | 2 | 10 | sdfg | | 11 | Tires/Wheels | text | 0 | 1 | 11 | | | 11 | Tires/Wheels | text | 0 | 2 | 11 | sdfg | | 12 | Condition | text | 1 | 1 | 12 | New | | 12 | Condition | text | 1 | 2 | 12 | sdfg | | 13 | Title | text | 0 | 1 | 13 | | | 13 | Title | text | 0 | 2 | 13 | sdfg | +----+--------------+----------+-----------+------------+--------------+-----------------+ I want to convert it to something more along the lines of: id, Make, Year, Type, Axles, Size, Frame (etc) 1, Apple, 2009, iPhone, ..... 2, sdfg, sdfg, sdfg, ..... Any suggestions?

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  • Why MSSQL keeps throwing me Exceptions?

    - by Augusto Càzares
    I have my project in .NET that uses a db in MSSQL Server,i'm using LINQ , sometimes when the projec throws me an exception (Constraint) in a part of the project this same error keeps showing in other part of the project when i do another thing with the db, like when i do an insertion and i had before an exception on delete the insertion throws me the delete exeption, and it remainds this way until i close and open again the project, my major problem is when this happen in my online project, this error in my project causes me problems in the project i'm testing online (i use the same db). I don't know if this exception is on the memory or something but its have been causing me a lot of headechs.

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  • Override Locale Date with custom setings.

    - by Frank Developer
    Aside from the GL Support, is there a way to override locale settings with custom values for month and day when using mmm-dd-yyyy, modified spanish examples: Jan = ENE, Aug = AGO, or long dates (mmmm) January = ENERO, August = AGOSTO, or (dddd) Monday = LUNES, Thursday = JUEVES, etc.?

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  • Getting a linq table to be dynamically sent to a method

    - by Damian Spaulding
    I have a procedure: var Edit = (from R in Linq.Products where R.ID == RecordID select R).Single(); That I would like to make "Linq.Products" Dynamic. Something like: protected void Page_Load(object sender, EventArgs e) { something(Linq.Products); } public void something(Object MyObject) { System.Data.Linq.Table<Product> Dynamic = (System.Data.Linq.Table<Product>)MyObject; var Edit = (from R in Dynamic where R.ID == RecordID select R).Single(); My problem is that I my "something" method will not be able to know what table has been sent to it. so the static line: System.Data.Linq.Table Dynamic = (System.Data.Linq.Table)MyObject; Would have to reflect somthing like: System.Data.Linq.Table Dynamic = (System.Data.Linq.Table)MyObject; With being a dynamic catch all variable so that Linq can just execute the code just like I hand coded it statically. I have been pulling my hair out with this one. Please help.

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  • count(*) is it really expensive ?

    - by Anil Namde
    I have a page where i have 4 tabs displaying 4 different reports based of different tables. Now i get row count of each tabled using select count() from table query and display number of rows available in each table on the tabs. Now with each page post back 5 count() queries are executed (4 to get counts and 1 for pagination) and 1 query for getting report. Now my question is should is count(*) query really expensive that i should keep the row counts (at least which are displayed on tab) in view state of page instead of queering each time? How much expensive it is ?

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  • postgres SQL - pg_class question

    - by Sachin Chourasiya
    PostgreSQL stores statistics about tables in the system table called pg_class. The query planner accesses this table for every query. These statistics may only be updated using the analyze command. If the analyze command is not run often, the statistics in this table may not be accurate and the query planner may make poor decisions which can degrade system performance. Another strategy is for the query planner to generate these statistics for each query (including selects, inserts, updates, and deletes). This approach would allow the query planner to have the most up-to-date statistics possible. Why postgres always rely on pg_class instead?

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  • Equivalent of Switch Statement in MySql 5

    - by Robert Gowland
    Using MySql 5, I have a task where I need to update one table based on the contents of another table. For example, I need to add 'A1' to table 'A' if table 'B' contains 'B1'. I need to add 'A2a' and 'A2b' to table 'A' if table 'B' contains 'B2', etc.. In our case, the value in table 'B' we're interested is an enum. Right now I have a stored procedure containing a series of statements like: INSERT INTO A SELECT 'A1' FROM B WHERE B.Value = 'B1'; --Repeat for 'B2' -> 'A2a', 'A2b'; 'B3' -> 'A3', etc... Is there a nicer more DRY way of accomplishing this?

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  • Change Label Control Property Based on Data from SqlDataSource Inside a Repeater

    - by Furqan Muhammad Khan
    I am using a repeater control to populate data from SqlDataSource into my custom designed display-box. <asp:Repeater ID="Repeater1" runat="server" DataSourceID="SqlDataSource1" OnDataBinding="Repeater_ItemDataBound"> <HeaderTemplate> </HeaderTemplate> <ItemTemplate> <div class="bubble-content"> <div style="float: left;"> <h2 class="bubble-content-title"><%# Eval("CommentTitle") %></h2> </div> <div style="text-align: right;"> <asp:Label ID="lbl_category" runat="server" Text=""><%# Eval("CommentType") %> </asp:Label> </div> <div style="float: left;"> <p><%# Eval("CommentContent") %></p> </div> </div> </ItemTemplate> <FooterTemplate> </FooterTemplate> </asp:Repeater> <asp:SqlDataSource ID="mySqlDataSource" runat="server" ConnectionString="<%$ ConnectionStrings:myConnectionString %>" SelectCommand="SELECT [CommentTitle],[CommentType],[CommentContent] FROM [Comments] WHERE ([PostId] = @PostId)"> <SelectParameters> <asp:QueryStringParameter Name="PostId" QueryStringField="id" Type="String" /> </SelectParameters> </asp:SqlDataSource> Now, there can be three types of "CommentTypes" in the database. I want to change the CssClass property of "lbl_category" based on the value of [CommentType]. I tried doing this: <asp:Label ID="lbl_category" runat="server" CssClass="<%# Eval("CommentType") %>" Text=""><%# Eval("CommentType") %></asp:Label> But this gives an error: "The server control is not well formed" and haven't been able to find a way to achieve this in the code behind. Can someone please help?

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