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  • Comparing fields of one table to other fields of another table

    - by chupinette
    Hello! I have a function called add_item which actually inserts values in a field item_name of temporary table called temp having fields temp_id and item_name. I have another table calleed item which consists of fields item_id, item_name, price. I have another table called quotation which consists of fields q_id, item_id,item_name,price. Now I cant figure out how do i compare the item_name from temp to the field item_name from item. And then, insert the values of item in quoatation table. Can anyone guide me please?

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  • How to use Common Table Expression and check no duplication in SQL Server

    - by vodkhang
    I have a table references to itself. User table: id, username, managerid and managerid links back to id Now, I want to get all the managers including direct manager, manager of direct manager, so on and so forth... The problem is that I do not want to have a unstop recursive sql. So, I want to check if an id alreay in a list, I will not include it anymore. Here is my sql for that: with all_managers (id, username, managerid, idlist) as ( select u1.id, u1.username, u1.managerid, ' ' from users u1, users u2 where u1.id = u2.managerid and u2.id = 6 UNION ALL select u.id, u.username, u.managerid, idlist + ' ' + u.id from all_managers a, users u where a.managerid = u.id and charindex(cast(u.id as nvarchar(5)), idlist) != 0 ) select id, username from all_managers; The problem is that in this line: select u1.id, u1.username, u1.managerid, ' ' The SQL Server complains with me that I can not put ' ' as the initialized for idlist. nvarchar(40) does not work as well. I do not know how to declare it inside a common table expression like this one. Usually, in db2, I can just put varchar(40) My sample data: ID UserName ManagerID 1 admin 1 2 a 1 3 b 1 4 c 2 What I want to do is that I want to find all managers of c guy. The result should be: admin, a, b. Some of the user can be his manager (like admin) because the ManagerID does not allow NULL and some does not have direct manager. With common table expression, it can lead to an infinite recursive. So, I am also trying to avoid that situation by trying to not include the id twice. For example, in the 1st iteration, we already have id : 1, so, in the 2nd iteration and later on, 1 should never be allowed. I also want to ask if my current approach is good or not and any other solutions? Because if I have a big database with a deep hierarchy, I will have to initialize a big varchar to keep it and it consumes memory, right?

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  • "select * from table" vs "select colA,colB,etc from table" interesting behaviour in SqlServer2005

    - by kristof
    Apology for a lengthy post but I needed to post some code to illustrate the problem. Inspired by the question What is the reason not to use select * ? posted a few minutes ago, I decided to point out some observations of the select * behaviour that I noticed some time ago. So let's the code speak for itself: IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[starTest]') AND type in (N'U')) DROP TABLE [dbo].[starTest] CREATE TABLE [dbo].[starTest]( [id] [int] IDENTITY(1,1) NOT NULL, [A] [varchar](50) NULL, [B] [varchar](50) NULL, [C] [varchar](50) NULL ) ON [PRIMARY] GO insert into dbo.starTest(a,b,c) select 'a1','b1','c1' union all select 'a2','b2','c2' union all select 'a3','b3','c3' go IF EXISTS (SELECT * FROM sys.views WHERE object_id = OBJECT_ID(N'[dbo].[vStartest]')) DROP VIEW [dbo].[vStartest] go create view dbo.vStartest as select * from dbo.starTest go go IF EXISTS (SELECT * FROM sys.views WHERE object_id = OBJECT_ID(N'[dbo].[vExplicittest]')) DROP VIEW [dbo].[vExplicittest] go create view dbo.[vExplicittest] as select a,b,c from dbo.starTest go select a,b,c from dbo.vStartest select a,b,c from dbo.vExplicitTest IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[starTest]') AND type in (N'U')) DROP TABLE [dbo].[starTest] CREATE TABLE [dbo].[starTest]( [id] [int] IDENTITY(1,1) NOT NULL, [A] [varchar](50) NULL, [B] [varchar](50) NULL, [D] [varchar](50) NULL, [C] [varchar](50) NULL ) ON [PRIMARY] GO insert into dbo.starTest(a,b,d,c) select 'a1','b1','d1','c1' union all select 'a2','b2','d2','c2' union all select 'a3','b3','d3','c3' select a,b,c from dbo.vExplicittest select a,b,c from dbo.vStartest If you execute the following query and look at the results of last 2 select statements, the results that you will see will be as follows: select a,b,c from dbo.vExplicittest a1 b1 c1 a2 b2 c2 a3 b3 c3 select a,b,c from dbo.vStartest a1 b1 d1 a2 b2 d2 a3 b3 d3 As you can see in the results of select a,b,c from dbo.vStartest the data of column c has been replaced with the data from colum d. I believe that is related to the way the views are compiled, my understanding is that the columns are mapped by column indexes (1,2,3,4) as apposed to names. I though I would post it as a warning for people using select * in their sql and experiencing unexpected behaviour. Note: If you rebuild the view that uses select * each time after you modify the table it will work as expected

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  • Finding column index using jQuery when table contains column-spanning cells

    - by Brant Bobby
    Using jQuery, how can I find the column index of an arbitrary table cell in the example table below, such that cells spanning multiple columns have multiple indexes? HTML <table> <tbody> <tr> <td>One</td> <td>Two</td> <td id="example1">Three</td> <td>Four</td> <td>Five</td> <td>Six</td> </tr> <tr> <td colspan="2">One</td> <td colspan="2">Two</td> <td colspan="2" id="example2">Three</td> </tr> <tr> <td>One</td> <td>Two</td> <td>Three</td> <td>Four</td> <td>Five</td> <td>Six</td> </tr> </tbody> </table> jQuery var cell = $("#example1"); var example1ColIndex = cell.parent("tr").children().index(cell); // == 2. This is fine. cell = $("#example2"); var example2ColumnIndex = cell.parent("tr").children().index(cell); // == 2. It should be 4 (or 5, but I only need the lowest). How can I do this?

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  • Temporary users table or legitimate users table?

    - by John
    I have a freelance web application that lets users register for events. In my database, I have a t_events_applicants table with the column t_events_applications.user_id with a foreign key constraint linked to the t_users.user_id column. So this means only users who have registered with my web application can register for my web application's events. My client would now like to allow non-registered users, users who do not have an entry in my t_user table, to register for events. These non-registered users only need to provide their name and email address to register for events. Should I create a t_temporary_user table with columns name and email and then remove the t_events_applicants.user_id fk constraint? Or should I add un-registered users to the t_user table and then add a column called t_user.type where type can be 'registered' or 'non-registered'? How do I decide which approach to go with? A lot of times, I hesitate with either approach. I ask myself, "What if at a later time, a temporary user is allowed to become a fully registered user? Then maybe I should have only a t_user table. But then I also don't feel good about storing a lot of temporary users in t_user."

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  • Update table variable with function

    - by Joris
    I got a table variable @RQ, I want it updated using a table-valued function. Now, I think I do the update wrong, because my function works... The function: ALTER FUNCTION [dbo].[usf_GetRecursiveFoobar] ( @para int, @para datetime, @para varchar(30) ) RETURNS @ReQ TABLE ( Onekey int, Studnr nvarchar(10), Stud int, Description nvarchar(32), ECTSGot decimal(5,2), SBUGot decimal(5,0), ECTSmax decimal(5,2), SBUmax decimal(5,0), IsFree bit, IsGot int, DateGot nvarchar(10), lvl int, path varchar(max) ) AS BEGIN; WITH RQ AS ( --RECURSIVE QUERY ) INSERT @ReQ SELECT RQ.Onekey, RQ.Studnr, RQ.Stud, RQ.Description, RQ.ECTSGot, RQ.SBUGot, RQ.ECTSmax, RQ.SBUmax, RQ.IsFree, RQ.IsGot, RQ.DatumGot, RQ.lvl, RQ.path FROM RQ RETURN END Now, when I run a simple query: DECLARE @ReQ TABLE ( OnderwijsEenheid_key int, StudentnummerHSA nvarchar(10), Student_key int, Omschrijving nvarchar(32), ECTSbehaald decimal(5,2), SBUbehaald decimal(5,0), ECTSmax decimal(5,2), SBUmax decimal(5,0), IsVrijstelling bit, IsBehaald int, DatumBehaald nvarchar(10), lvl int, path varchar(max) ) INSERT INTO @ReQ SELECT * FROM usf_GetRecursiveFoobar(@para1, @para2, @para3) I got error: Msg 8152, Level 16, State 13, Line 20 String or binary data would be truncated. The statement has been terminated. Why? What to do about it?

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  • Predefined column names in SQL Server pivot table

    - by Marcos Buarque
    Hi, the other day I opened a topic here in StackOverflow (stackoverflow.com/questions/4663698/how-can-i-display-a-consolidated-version-of-my-sql-server-table). At that time I needed help on how to show data on a pivot table. From the help I got here in the forum, my research led me to this page about dynamic SQL: www.sommarskog.se/dynamic_sql.html. And then it led me to this awesome SQL script by Itzik Ben-Gan that will create a stored procedure that outputs a pivot table exactly the way I want: sommarskog.se/pivot_sp.sp. Well, almost. I need one change in this stored procedure. Instead of having dynamic column names pulled from the @on_cols variable in the SPROC, I need the output table to hold generic column names in simple ASC order. Could be, for example, col1, col2, col3, col4 ... The dynamic column names are a problem for me. So I need them named by their index in the order they appear. I have tried all sorts of things changing this great SQL script, but it won't work. I did not paste the code from the author because it is too long, but the link above will get us there. Any help appreciated. Thank you very much

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  • Using Partitions for a large MySQL table

    - by user293594
    An update on my attempts to implement a 505,000,000-row table on MySQL on my MacBook Pro: Following the advice given, I have partitioned my table, tr: i UNSIGNED INT NOT NULL, j UNSIGNED INT NOT NULL, A FLOAT(12,8) NOT NULL, nu BIGINT NOT NULL, KEY (nu), key (A) with a range on nu. nu ought to be a real number, but because I only have 6-d.p. accuracy and the maximum value of nu is 30000. I multiplied it by 10^8 made it a BIGINT - I gather one can't use FLOAT or DOUBLE values to PARTITION a MySQL table. Anyway, I have 15 partitions (p0: nu<25,000,000,000, p1: nu<50,000,000,000, etc.). I was thinking that this should speed up a typical to SELECT: SELECT * FROM tr WHERE nu>95000000000 AND nu<100000000000 AND A.>1. to something of the order of the same query on a table consisting of only the data in the relevant partition (<30 secs). But it's taking 30mins+ to return rows for queries within a partition and double that if the query is for rows spanning two (contiguous) partitions. I realise I could just have 15 different tables, and query them separately, but is there a way to do this 'automatically' with partitions? Has anyone got any suggestions?

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  • How to transform vertical table into horizontal table?

    - by avivo
    Hello, I have one table Person: Id Name 1 Person1 2 Person2 3 Person3 And I have its child table Profile: Id PersonId FieldName Value 1 1 Firstname Alex 2 1 Lastname Balmer 3 1 Email [email protected] 4 1 Phone +1 2 30004000 And I want to get data from these two tables in one row like this: Id Name Firstname Lastname Email Phone 1 Person1 Alex Balmer [email protected] +1 2 30004000 What is the most optimized query to get these vertical (key, value) values in one row like this? Now I have a problem that I done four joins of child table to parent table because I need to get these four fields. Some optimization is for sure possible. I would like to be able to modify this query in easy way when I add new field (key,value). What is the best way to do this? To create some StoreProcedure? I would like to have strongly types in my DB layer (C#) and using LINQ (when programming) so it means when I add some new Key, Value pair in Profile table I would like to do minimal modifications in DB and C# if possible. Actually I am trying to get some best practices in this case.

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  • Delete ONE SPECIFIC table of a database - leave the rest intact

    - by Jayomat
    Hi, I have a database where I store two different kinds of data. One table is for favorite routes, the other stores the retrieved routes from a server. I can retrieve the routes etc just fine. But after retrieving the first Route, pressing back or HOME, and then retrieving another route, the routes table is filled with all the old routes plus the new ones. So my question: how do I delete ONLY the routes table and not the whole database because I don't want to delete the added favorites....?! I found the following function in the android docs: public int delete (String table, String whereClause, String[] whereArgs) and I tried to implement it, but I must pass a SQLiteDataBase as an argument. But how? I implemented: public void deleteTableRoutes(SQLiteDataBase db){ db.delete("routes", null, null); } But I want to call this function from a different class where I have no reference to the database.. so what do I have to pass as an argument? Or how do I get a reference to my database? I build my database upon the code example of the NotePadExample from the dev docs. How to solve this problem? thanks

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  • how to link table to table

    - by Niño Seymour L. Rodriguez
    I am a comsci student and I'm taking up database now. I got a problem in or should I say I dont know how to link table to table. It is not like you'll just use a foreign key and connect it to the primary key. The outcome should be like this: In the table Course there are three fields namely "course_id", "Description" and "subjects". When you click the name field Subject, a table named Subject should appear. Can you help me with this? hope you understnd my grammar, hehe..im not good in english......it will be a big help if you can answer it.........thank you po..............

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  • Well written open source java projects

    - by Algorist
    I want to improve my design and programming skills by understanding design & code of open source projects. I downloaded hadoop,groovy but they are very difficult to follow. I am not having a clue of how to follow this code without having a high level overview of the design. Any suggestions?? Thank you.

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  • Jquery Hidden Field in Table

    - by zSysop
    Hi all, I was wondering if anyone knew of a way to access a hidden field (by client id) within a table row using jquery. $("#tblOne").find("tr").click(function() { var worker = $(this).find(":input").val(); }); I find that the above works for a row that has only one input, but i need some help figuring out a way to get the value by the inputs name. Here's the example of a table row. How would i access the two fields by their id's? <table id="tblOne"> <tr> <td> <asp:HiddenField id="hdnfld_Id" Text='<% Eval("ID") %>'></asp:HiddenField> </td> <td> <asp:HiddenField id="hdnfld_Id2" Text='<% Eval("ID2") %>'></asp:HiddenField> </td> </tr> </table>

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  • Is it possible to filter data used by pivot table based on filtering the rows in a source table in Excel?

    - by Geoffrey Stoel
    I have developed a dashboard in Excel 2007 that uses one source table in a sheet (being filled with a query on our data warehouse) and multiple pivot tables making different cross sections on this data. I use the GETPIVOTDATA in almost a hundred formulas to give me the right value for a specific indicator in my dashboard. This all works fine. However I now have received the question to make the dashboard for 5 different segments. As you can imagine I don't want to create 5 different workbooks for this and need to maintain the dashboard logic on all of them. So my question is the following. Is it possible to automatically (through VBA or any other means) filter the results in my source table which is the source for my pivot tables and thus for my dashboard values. So schematically: DATABASE_VIEW -- SOURCE_TABLE -- 12 pivot tables -- 100 GETPIVOTDATA functions Preferably I would like to load all the segments in the source_table (one view on my database) and then filter the data in the source table, which results in filterd source_dat for my pivots. This way I can (without requerying the db) quickly change between segments in the dashboards (refreshing pivots only). Data in the source table has the column: CUSTOMER_SEGMENT available to filter upon. Any help is appreciated. Geoffrey

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  • How to get all Div within a table using javascript

    - by Rajesh Rolen- DotNet Developer
    please tell me how can i get array of all Those DIV of specific table whose LANG="1" using javascript table structure is like this: < table > < tr > < td > < div id=1 lang="1" > some metter < /div > < /td >< /tr > < tr > < td > < div id=2 lang="2" > some metter < /div > < /td >< /tr > < tr > < td > < div id=3 lang="1" > some metter < /div > < /td >< /tr > < tr > < td > < div id=4 lang="1" > some metter < /div > < /td >< /tr > < /table >

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  • Developing multiple user interfaces for an application

    - by denizkocak
    I want to develop an application which has a graphical user interface that could be developed by using different widget toolkits. For example I want to use Qt, GTK+ or even ncurses as a building block for my user interface for the same application. Moreover users could choose which GUI implementation will be used during the next startup of the application without recompiling it first. I wonder what are possible design strategies and design patterns used in the implementation of this design?

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  • how to generate the "create table" sql statement for an existing table in postgreSQL

    - by Raja
    I have a table created long ago in postgreSQL. Now i want to look at the sql statement used to create it but cannot figure it out. Also when i do the \dS+ tablename it says table not found, but \dt+ tablename is working fine. The \dS+ lists all the table names owned by the root postgres user and doesn't show up tables that i created with my user account. Any help is greatly appreciated. Thanks

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  • Ruby on Rails : How can i display data for the current view from a different table

    - by krishkule
    This might be a easy-to-answer question, but its a pain in the bum for me.... So... I have two tables - Chords - |id|chord|name|rating|artist_id| Artists - |id|artist| (the relations : chords : belongs_to :artist artists : has_many :chords ) And in the index page for "chords" i want to display chord,name,rating from Chords table AND artist from the Artists table this is the code for the chrod's index.html.erb : <table border="1"> <%@chords.each do |chord|%> <tr> <td><%=chord.artist.artist%></td> <td><%= link_to chord.name, chord %></td> <td><%=chord.rating%></td> <td><%= chord.created_at %></td> </tr> <%end%> </table> The error message is : undefined method `artist' for nil:NilClass Actually, at first it worked, but when i started to create the "new.html.erb" page and the create,new controllers, it stopped working - thats why this is so confusing for me! I will be glad to hear any critique and suggestions! Thank you

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  • Counting in R data.table

    - by Simon Z.
    I have the following data.table set.seed(1) DT <- data.table(VAL = sample(c(1, 2, 3), 10, replace = TRUE)) VAL 1: 1 2: 2 3: 2 4: 3 5: 1 6: 3 7: 3 8: 2 9: 2 10: 1 Now I want to to perform two tasks: Count the occurrences of numbers in VAL. Count within all rows with the same value VAL (first, second, third occurrence) At the end I want the result VAL COUNT IDX 1: 1 3 1 2: 2 4 1 3: 2 4 2 4: 3 3 1 5: 1 3 2 6: 3 3 2 7: 3 3 3 8: 2 4 3 9: 2 4 4 10: 1 3 3 where COUNT defines task 1. and IDX task 2. I tried to work with which and length using .I: dt[, list(COUNT = length(VAL == VAL[.I]), IDX = which(which(VAL == VAL[.I]) == .I))] but this does not work as .I refers to a vector with the index, so I guess one must use .I[]. Though inside .I[] I again face the problem, that I do not have the row index and I do know (from reading data.table FAQ and following the posts here) that looping through rows should be avoided if possible. So, what's the data.table way?

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  • Placeholder containing dynamic table is empty unless I create table twice

    - by Mike O.
    I am dynamically creating a table that contains a textbox in each cell. The table is put in a placeholder control. Everything displays perfectly. The problem is when I go to retrieve the values entered in the cells. I have the code to generate the table in a separate method called CreateTable(). In order for my program to find a table in the placeholder when I go to save, I have to run CreateTable() in a postback event AND in the PageLoad event. If I call CreateTable() in only one of those places and I try to save, it says the placeholder is empty and, therefore, I cannot save the textbox contents. I've tried calling CreateTable() from InitLoad but that doesn't work because it needs to reference values from three static controls: 1 dropdown, 1 listbox, and 1 calendar control, which I don't believe have had their viewstate rendered yet. Anyone have any ideas? It would sure be nice not to have to double the number of database calls just to make this work.

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  • Object oriented n-tier design. Am I abstracting too much? Or not enough?

    - by max
    Hi guys, I'm building my first enterprise grade solution (at least I'm attempting to make it enterprise grade). I'm trying to follow best practice design patterns but am starting to worry that I might be going too far with abstraction. I'm trying to build my asp.net webforms (in C#) app as an n-tier application. I've created a Data Access Layer using an XSD strongly-typed dataset that interfaces with a SQL server backend. I access the DAL through some Business Layer Objects that I've created on a 1:1 basis to the datatables in the dataset (eg, a UsersBLL class for the Users datatable in the dataset). I'm doing checks inside the BLL to make sure that data passed to DAL is following the business rules of the application. That's all well and good. Where I'm getting stuck though is the point at which I connect the BLL to the presentation layer. For example, my UsersBLL class deals mostly with whole datatables, as it's interfacing with the DAL. Should I now create a separate "User" (Singular) class that maps out the properties of a single user, rather than multiple users? This way I don't have to do any searching through datatables in the presentation layer, as I could use the properties created in the User class. Or would it be better to somehow try to handle this inside the UsersBLL? Sorry if this sounds a little complicated... Below is the code from the UsersBLL: using System; using System.Data; using PedChallenge.DAL.PedDataSetTableAdapters; [System.ComponentModel.DataObject] public class UsersBLL { private UsersTableAdapter _UsersAdapter = null; protected UsersTableAdapter Adapter { get { if (_UsersAdapter == null) _UsersAdapter = new UsersTableAdapter(); return _UsersAdapter; } } [System.ComponentModel.DataObjectMethodAttribute (System.ComponentModel.DataObjectMethodType.Select, true)] public PedChallenge.DAL.PedDataSet.UsersDataTable GetUsers() { return Adapter.GetUsers(); } [System.ComponentModel.DataObjectMethodAttribute (System.ComponentModel.DataObjectMethodType.Select, false)] public PedChallenge.DAL.PedDataSet.UsersDataTable GetUserByUserID(int userID) { return Adapter.GetUserByUserID(userID); } [System.ComponentModel.DataObjectMethodAttribute (System.ComponentModel.DataObjectMethodType.Select, false)] public PedChallenge.DAL.PedDataSet.UsersDataTable GetUsersByTeamID(int teamID) { return Adapter.GetUsersByTeamID(teamID); } [System.ComponentModel.DataObjectMethodAttribute (System.ComponentModel.DataObjectMethodType.Select, false)] public PedChallenge.DAL.PedDataSet.UsersDataTable GetUsersByEmail(string Email) { return Adapter.GetUserByEmail(Email); } [System.ComponentModel.DataObjectMethodAttribute (System.ComponentModel.DataObjectMethodType.Insert, true)] public bool AddUser(int? teamID, string FirstName, string LastName, string Email, string Role, int LocationID) { // Create a new UsersRow instance PedChallenge.DAL.PedDataSet.UsersDataTable Users = new PedChallenge.DAL.PedDataSet.UsersDataTable(); PedChallenge.DAL.PedDataSet.UsersRow user = Users.NewUsersRow(); if (UserExists(Users, Email) == true) return false; if (teamID == null) user.SetTeamIDNull(); else user.TeamID = teamID.Value; user.FirstName = FirstName; user.LastName = LastName; user.Email = Email; user.Role = Role; user.LocationID = LocationID; // Add the new user Users.AddUsersRow(user); int rowsAffected = Adapter.Update(Users); // Return true if precisely one row was inserted, // otherwise false return rowsAffected == 1; } [System.ComponentModel.DataObjectMethodAttribute (System.ComponentModel.DataObjectMethodType.Update, true)] public bool UpdateUser(int userID, int? teamID, string FirstName, string LastName, string Email, string Role, int LocationID) { PedChallenge.DAL.PedDataSet.UsersDataTable Users = Adapter.GetUserByUserID(userID); if (Users.Count == 0) // no matching record found, return false return false; PedChallenge.DAL.PedDataSet.UsersRow user = Users[0]; if (teamID == null) user.SetTeamIDNull(); else user.TeamID = teamID.Value; user.FirstName = FirstName; user.LastName = LastName; user.Email = Email; user.Role = Role; user.LocationID = LocationID; // Update the product record int rowsAffected = Adapter.Update(user); // Return true if precisely one row was updated, // otherwise false return rowsAffected == 1; } [System.ComponentModel.DataObjectMethodAttribute (System.ComponentModel.DataObjectMethodType.Delete, true)] public bool DeleteUser(int userID) { int rowsAffected = Adapter.Delete(userID); // Return true if precisely one row was deleted, // otherwise false return rowsAffected == 1; } private bool UserExists(PedChallenge.DAL.PedDataSet.UsersDataTable users, string email) { // Check if user email already exists foreach (PedChallenge.DAL.PedDataSet.UsersRow userRow in users) { if (userRow.Email == email) return true; } return false; } } Some guidance in the right direction would be greatly appreciated!! Thanks all! Max

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  • SQL - table alias scope.

    - by Support - multilanguage SO
    I've just learned ( yesterday ) to use "exists" instead of "in". BAD select * from table where nameid in ( select nameid from othertable where otherdesc = 'SomeDesc' ) GOOD select * from table t where exists ( select nameid from othertable o where t.nameid = o.nameid and otherdesc = 'SomeDesc' ) And I have some questions about this: 1) The explanation as I understood was: "The reason why this is better is because only the matching values will be returned instead of building a massive list of possible results". Does that mean that while the first subquery might return 900 results the second will return only 1 ( yes or no )? 2) In the past I have had the RDBMS complainin: "only the first 1000 rows might be retrieved", this second approach would solve that problem? 3) What is the scope of the alias in the second subquery?... does the alias only lives in the parenthesis? for example select * from table t where exists ( select nameid from othertable o where t.nameid = o.nameid and otherdesc = 'SomeDesc' ) AND select nameid from othertable o where t.nameid = o.nameid and otherdesc = 'SomeOtherDesc' ) That is, if I use the same alias ( o for table othertable ) In the second "exist" will it present any problem with the first exists? or are they totally independent? Is this something Oracle only related or it is valid for most RDBMS? Thanks a lot

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