Search Results

Search found 27339 results on 1094 pages for 'sql dmv'.

Page 608/1094 | < Previous Page | 604 605 606 607 608 609 610 611 612 613 614 615  | Next Page >

  • Question about Cost in Oracle Explain Plan

    - by Will
    When Oracle is estimating the 'Cost' for certain queries, does it actually look at the amount of data (rows) in a table? For example: If I'm doing a full table scan of employees for name='Bob', does it estimate the cost by counting the amount of existing rows, or is it always a set cost?

    Read the article

  • Extending LINQ classes to my own partial classes in different namespaces?

    - by sah302
    I have a .dbml file which of course contains the auto-generated classes based on my tables. I would however, like to extend them to my own classes. Typically I design such that each of my tables get their own namespace in their own folder containing all of their associated dao and service classes. So if I am dealing with a page that only has to do with 'customers' for instance, I can only include the customerNS. But when using LINQ I seem to be unable to do this. I have tried removing a default namespace from the project, I have tried putting the .dbml file into it's own folder with a custom namespace and then adding a 'using' statement, but no nothing works. I also saw the Entity Namespace, Context Namespace, and Custom Tool Namespace properties associated with the .dbml file and tried setting all these to names x and trying 'using x' in my other class to allow me to extend partial classes, but it just doesn't work. Is this possible or do I have to keep all extended partial classes in the same namespace as the .dbml file?

    Read the article

  • how to design a schema where the columns of a table are not fixed

    - by hIpPy
    I am trying to design a schema where the columns of a table are not fixed. Ex: I have an Employee table where the columns of the table are not fixed and vary (attributes of Employee are not fixed and vary). Nullable columns in the Employee table itself i.e. no normalization Instead of adding nullable columns, separate those columns out in their individual tables ex: if Address is a column to be added then create table Address[EmployeeId, AddressValue]. Create tables ExtensionColumnName [EmployeeId, ColumnName] and ExtensionColumnValue [EmployeeId, ColumnValue]. ExtensionColumnName would have ColumnName as "Address" and ExtensionColumnValue would have ColumnValue as address value. Employee table EmployeeId Name ExtensionColumnName table ColumnNameId EmployeeId ColumnName ExtensionColumnValue table EmployeeId ColumnNameId ColumnValue There is a drawback is the first two ways as the schema changes with every new attribute. Note that adding a new attribute is frequent. I am not sure if this is the good or bad design. If someone had a similar decision to make, please give an insight on things like foreign keys / data integrity, indexing, performance, reporting etc.

    Read the article

  • Problem with LINQ in C#

    - by David Bonnici
    I am encountering a problem when using LINQ in C#, I am constantly getting "Specified cast is not valid". This is what I am trying to do. I create a class in which I declare all the columns of the table. [Table(Name="tbl_Aff")] public class Affiliate { [Column] public string name; [Column] public string firstname; [Column] public string surname; [Column] public string title; } I then declare a strongly typed DataContext in which I declare all Table collections as members of the context. public partial class Database : DataContext { public Table affiliate; public Database() : base(Settings.getConnectionString()) { } //This method gets the connection string by reading from an XML file. } public partial class Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { Database database = new Database(); try { var q = from a in database.affiliate select a; foreach (var aff in q) // Here I get the error "Specified cast is not valid" { lblMessage.InnerHtml += aff.name + ""; } } catch (Exception ex) { System.Console.WriteLine(ex.Message); } } }

    Read the article

  • How to avoid timestamp issue in a long query?

    - by pingi
    Hi, I have the following 2 tables: items: id int primary key bla text events: id_items int num int when timestamp without time zone ble text composite primary key: id_items, num and want to select to each item the most recent event (the newest 'when'). I wrote an request, but I don't know if it could be written more efficiently. Also on PostgreSQL there is a issue with comparing Timestamp objects: 2010-05-08T10:00:00.123 == 2010-05-08T10:00:00.321 so I select with 'MAX(num)' Any thoughts how to make it better? Thanks. SELECT i.*, ea.* FROM items AS i JOIN ( SELECT t.s AS t_s, t.c AS t_c, max(e.num) AS o FROM events AS e JOIN ( SELECT DISTINCT id_item AS s, MAX(when) AS c FROM events GROUP BY s ORDER BY c ) AS t ON t.s = e.id_item AND e.when = t.c GROUP BY t.s, t.c ) AS tt ON tt.t_s = i.id JOIN events AS ea ON ea.id_item = tt.t_s AND ea.cas = tt.t_c AND ea.num = tt.o;

    Read the article

  • make multiple, composite query in oracle

    - by Meloun
    How can i make multiple, composite query in oracle? for example this several queries in one step? 1 CREATE TABLE test (id NUMBER PRIMARY KEY, name VARCHAR2(30)); 2 CREATE SEQUENCE test_sequence START WITH 1 INCREMENT BY 1; 3 CREATE OR REPLACE TRIGGER test_trigger BEFORE INSERT ON test REFERENCING NEW AS NEW FOR EACH ROW BEGIN SELECT test_sequence.nextval INTO :NEW.ID FROM dual; END; 4 INSERT INTO test (name) VALUES ('Jon'); 5 INSERT INTO test (name) VALUES ('Meloun');

    Read the article

  • Complex SQL query, one to many relationship

    - by Ethan
    Hey SO, I have a query such that I need to get A specific dog All comments relating to that dog The user who posted each comment All links to images of the dog the user who posted each link I've tried a several things, and can't figure out quite how to work it. Here's what I have (condensed so you don't have to wade through it all): SELECT s.dog_id, s.name, c.comment, c.date_added AS comment_date_added, u.username AS comment_username, u.user_id AS comment_user_id, l.link AS link, l.date_added AS link_date_added, u2.username AS link_username, u2.user_id AS link_user_id FROM dogs AS d LEFT JOIN comments AS c ON c.dog_id = d.dog_id LEFT JOIN users AS u ON c.user_id = u.user_id LEFT JOIN links AS l ON l.dog_id = d.dog_id LEFT JOIN users AS u2 ON l.user_id = u2.user_id WHERE d.dog_id = '1' It's sorta close to working, but it'll only return me the first comment, and the first link all as one big array with all the info i requested. The are multiple comments and links per dog, so I need it to give me all the comments and all the links. Ideally it'd return an object with dog_id, name, comments(an array of the comments), links(an array of the links) and then comments would have a bunch of comments, date_added, username, and user_id and links would have a bunch of links with link, date_added, username and user_id. It's got to work even if there are no links or comments. I learned the basics of mySQL somewhat recently, but this is pretty far over my head. Any help would be wonderful. Thanks!

    Read the article

  • (N)Hibernate: deleting orphaned ternary association rows when either associated row is deleted.

    - by anthony
    I have a ternary association table created using the following mapping: <map name="Associations" table="FooToBar"> <key column="Foo_id"/> <index-many-to-many class="Bar" column="Bar_id"/> <element column="AssociationValue" /> </map> I have 3 tables, Foo, Bar, and FooToBar. When I delete a row from the Foo table, the associated row (or rows) in FooToBar is automatically deleted. This is good. When I delete a row from the Bar table, the associated row (or rows) in FooToBar remain, with a stale reference to a Bar id that no longer exists. This is bad. How can I modify my hbm.xml to remove stale FooToBar rows when deleting from the Bar table?

    Read the article

  • Is closing/disposing an SqlDataReader needed if you are already closing the sqlconnection?

    - by Brian
    I noticed This question, but my question is a bit more specific. Is there any advantage to using using (SqlConnection conn = new SqlConnection(conStr)) { using (SqlCommand command = new SqlCommand()) { // dostuff } } instead of using (SqlConnection conn = new SqlConnection(conStr)) { SqlCommand command = new SqlCommand(); // dostuff } Obviously it does matter run more than one command with the same connection, since closing an SqlDataReader is more efficient than closing and reopening a connection (calling conn.Close();conn.Open(); will also free up the connection). I see many people insist that failure to close the DataReader means leaving open connection resources around, but doesn't that only apply if you don't close the connection?

    Read the article

  • rails: date type and GetDate

    - by cbrulak
    This is a follow up to this question: http://stackoverflow.com/questions/2930256/unique-responses-rails-gem I'm going to create an index based on the user id, url and a date type. I want date type (not datetime type) because I want the day, the 24 hour day to be part of the index to avoid duplication of page views counts on the same day. In other words: A view only counts once in a day by a visitor. I also want the default value of that column (viewdate) to be the function GETDATE(). This is what I have in my migration: execute "ALTER TABLEpage_viewsADD COLUMN viewdate datetime DEFAULTGETDATE()`" But the value viewdate is always empty. What am I missing? (as an aside, any other suggestions for accomplishing this goal?)

    Read the article

  • How to insert an integer into a database through command prompt

    - by jpavlov
    I am trying to insert a integer into a database in C# using the code below, but everytime I run the compiler informs me that my integer is not a valid column "Invalid Column Name UserID" Does anyone have any insight on this? Thanks. Console.WriteLine("Please enter a new User Id"); string line = Console.ReadLine(); int UserID; if (int.TryParse(line, out UserID)) { Console.WriteLine(UserID); Console.ReadLine(); } //Prepare the command string string insertString = @"INSERT INTO tb_User(ID,f_Name, l_Name) VALUES (UserID,'Ted','Turner')";

    Read the article

  • Is it possible to have a tableless select with multiple rows?

    - by outis
    A SELECT without a FROM clause gets us a multiple columns without querying a table: SELECT 17+23, REPLACE('bannanna', 'nn', 'n'), RAND(), CURRENT_TIMESTAMP; How can we write a query that results in multiple rows without referring to a table? Basically, abuse SELECT to turn it into a data definition statement. The result could have a single column or multiple columns. I'm most interested in a DBMS neutral answer, but others (e.g. based on UNPIVOT) are welcome. There's no technique application behind this question; it's more theoretical than practical.

    Read the article

  • How can I update a record using a correlated subquery?

    - by froadie
    I have a function that accepts one parameter and returns a table/resultset. I want to set a field in a table to the first result of that recordset, passing in one of the table's other fields as the parameter. If that's too complicated in words, the query looks something like this: UPDATE myTable SET myField = (SELECT TOP 1 myFunctionField FROM fn_doSomething(myOtherField) WHERE someCondition = 'something') WHERE someOtherCondition = 'somethingElse' In this example, myField and myOtherField are fields in myTable, and myFunctionField is a field return by fn_doSomething. This seems logical to me, but I'm getting the following strange error: 'myOtherField' is not a recognized OPTIMIZER LOCK HINTS option. Any idea what I'm doing wrong, and how I can accomplish this? *UPDATE: * Based on Anil Soman's answer, I realized that the function is expecting a string parameter and the field being passed is an integer. I'm not sure if this should be a problem as an explicit call to the function using an integer value works - e.g. fn_doSomething(12345) seems to automatically cast the number to an string. However, I tried to do an explicit cast: UPDATE myTable SET myField = (SELECT TOP 1 myFunctionField FROM fn_doSomething(CAST(myOtherField AS varchar(1000))) WHERE someCondition = 'something') WHERE someOtherCondition = 'somethingElse' Now I'm getting the following error: Line 5: Incorrect syntax near '('.

    Read the article

  • SSRS Dynamic Returning Dataset Collection Field in Expression

    - by Ray Clark
    I wrote a custom assembly to take a parameter value from the report and return a field from the dataset collection. My assembly returns the correct fields!name.value, but it shows me the string representation of it. How can I get it to resolve as the actual fields!name.value to display the actual data in the dataset? If I enter fields!name.value in manually it works fine showing me the value. If I resolve it with my custom code it display "fields!name.value" to me in the cell.

    Read the article

  • Which Oracle table uses a sequence?

    - by Jaú
    Having a sequence, I need to find out which table.column gets its values. As far as I know, Oracle doesn't keep track of this relationship. So, looking up for the sequence in source code would be the only way. Is that right? Anyone knows of some way to find out this sequence-table relationship?

    Read the article

  • Unit testing a SQL code generator

    - by Tom H.
    The team I'm on is currently writing code in TSQL to generate TSQL code that will be saved as scripts and later run. We're having a little difficulty in separating our unit tests between testing the code generator parts and testing the actual code that they generate. I've read through another similar question, but I was hoping to get some specific examples of what kind of unit test cases we might have. As an example, let's say that I have a bit of code that simply generates a DROP statement for a view, given the view schema and name. Do I just test that the generated code matches some expected outcome using string comparisons and then in a later integration or system test make sure that the drop actually drops the view if it exists, does nothing if the view doesn't exist, or raises an error if the view is one that we are marking as not allowing a drop? Thanks for any advice!

    Read the article

  • TSQL: grouping customer orders by week

    - by fishhead
    I have a table with a collection of orders. The fields are: customerName (text) DateOfOrder (datetime). I would like to show totals of orders per week per customer. I would like to have it arranged for the Friday of each week so that it looks like this: all dates follow mm/dd/yyyy "bobs pizza", 3/5/2010, 10 "the phone co",3/5/2010,5 "bobs pizza", 3/12/2010, 3 "the phone co",3/12/2010,11 Could somebody please show me how to do this? Thanks

    Read the article

  • LinQ: Add list to a list

    - by JohannesBoersma
    I have the following code: var columnNames = (from autoExport in dataContext.AutoExports where autoExport.AutoExportTemplate != null && ContainsColumn(autoExport.AutoExportTemplate, realName) select GetDbColumnNames(autoExport.AutoExportTemplate, realName)).ToList(); Where the function GetDbColumns() returns an List<string>. So columNames is of the type List<List<string>>. Is it possible to create a List<string>, so each element of the list of GetDbColumns is added to the result of the LinQ query?

    Read the article

  • MSSQL in ASP.NET application getting unstable after a certain period

    - by Barslett
    Hello, I have an ASP.NET 2.0 application that I made to keep track of disruption reports about our public transport system. The architecture is pretty straight-forward; an MSSQL Express 2008 database, ADO.NET and a DataSet/DAL with a few methods to access the database. There is a set of .aspx pages for the UI in use by our dispatchers and on our public website, as well as a set of SOAP and REST webservices and an RSS feed. Everything worked just fine for more than a year, until two weeks ago. Now and then, it seems as the database enters an unstable mode, and the application starts responding something right, something wrong. The typical error is that apparently, an empty DataTable is returned to the public disruption overview or to the RSS generator. Thus, the user gets e.g. an empty GridView, but no exception is thrown AFAIK, and nothing is written to the Windows Application log. After a restart of the MSSQL Express service, the situation is back to normal. It has to be said that the situation first time appeared a few days after I made a new minor upgrade of the application. The RSS generator was slightly rewritten, and I added a WCF REST service. But the DAL and the database schema were untouched... Any hints of how we could keep the database stable? It is a bit annoying not to have a clue ;-)

    Read the article

  • database setup for web application

    - by vbNewbie
    I have an application that requires a database and I have already setup tables but not sure if they match the requirements of the app. The app is a crawler which fetches web urls, crawls and stores appropriate urls and posts and all this is based on client requests which are stored as projects. So for each url stored there is one post and for client there are many projects and for each project there are many types of requests. So we get a client with a request and assign them a project name and then use the request to search for content and store the url and post. A request could already exist and should not be duplicated but should be associated with the right client and project and post etc. Here is my schema now: url table: urlId PK queryId FK url post table: postId PK urlId FK post date request table: queryId PK request client table: clientId PK client Name projectId FK project table: projectID PK queryID FK project Does this look right? or does anyone have suggestions. Of course my stored procedures and insert statements will have to be in depth.

    Read the article

  • SYSDATE - 1 error on pl/sql function

    - by ayo
    Hi curtisk/all, I have an issue: when i issue this function below ti gives me the following error: select 'EXECUTE DBMS_LOGMNR.ADD_LOGFILE(LOGFILENAME =>'''||name||'''||,OPTIONS=>DBMS_LOGMNR.NEW);' from v\$archived_log where name is not null; select 'EXECUTE DBMS_LOGMNR.ADD_LOGFILE(LOGFILENAME =>'''||name||'''||,OPTIONS=>DBMS_LOGMNR.ADDFILE);' from v\$archived_log where name is not null; EXECUTE DBMS_LOGMNR.START_LOGMNR( STARTTIME => SYSDATE - 1, ENDTIME => SYSDATE, OPTIONS => DBMS_LOGMNR.DICT_FROM_ONLINE_CATALOG + DBMS_LOGMNR.CONTINUOUS_MINE + DBMS_LOGMNR.COMMITTED_DATA_ONLY + DBMS_LOGMNR.PRINT_PRETTY_SQL); Error: * ERROR at line 1: ORA-01291: missing logfile ORA-06512: at "SYS.DBMS_LOGMNR", line 58 ORA-06512: at line 1 But i have added all the archived logs for several days before and my sysdate is at today. Kindly help out on this issue. thanks. Reagrds Ayo

    Read the article

< Previous Page | 604 605 606 607 608 609 610 611 612 613 614 615  | Next Page >