Search Results

Search found 27519 results on 1101 pages for 'sql learner'.

Page 651/1101 | < Previous Page | 647 648 649 650 651 652 653 654 655 656 657 658  | Next Page >

  • How to analyse Wikipedia article's data base with R?

    - by Tal Galili
    Hi all, This is a "big" question, that I don't know how to start, so I hope some of you can give me a direction. And if this is not a "good" question, I will close the thread with an apology. I wish to go through the database of Wikipedia (let's say the English one), and do statistics. For example, I am interested in how many active editors (which should be defined) Wikipedia had at each point of time (let's say in the last 2 years). I don't know how to build such a database, how to access it, how to know which types of data it has and so on. So my questions are: What tools do I need for this (besides basic R) ? MySQL on my computer? RODBC database connection? How do you start planning for such a project?

    Read the article

  • How would I associate a "Note" class to 4+ classes without creating lookup table for each associatio

    - by Gthompson83
    Im creating a project tasklist application. I have project, section, task, issue classes, and would like to use one class to be able to add simple notes to any object instance of those classes. The task, issue tables both use a standard identity field as a primary key. The section table has a two field primary key. The project table has a single int primary key defined by the user. Is there a way to associate the note class with each of these without using a seperate lookup table for each class? I'm not so sure my original idea is a decent way to implement this. I considered the following (each variable mapping to a field n the notes table. Private _NoteId As Integer Private _ProjectId As Integer Private _SectionId As Integer Private _SectionId2 As Integer Private _TaskId As Integer Private _IssueId As Integer Private _Note As String Private _UserId As Guid Then I would be able to write seperate methods (getProjectNotes, getTaskNotes) to get notes attached to each class. I started writing this a few weeks ago but got pulled away before i could finish. When revisiting this code today my first thought "this is retarded". Thoughts on drawbacks to this design?

    Read the article

  • How to use a varying database?

    - by nimo
    I want to use a database which name is stored in a variable. How do I do this? I first thought this would work but it doesn't: exec('use '+@db) That will not change database context Suggestions anyone?

    Read the article

  • Removing certain characters in all rows that match a regex?

    - by user001
    I'd like to change {foo, {bar}, foobar} to {foo, bar, foobar} in all rows that match '{.*{'. I.e. remove all curly braces { and } except the outer most pair. So doing mysql -h $H -u $U -p$P $DB -B -e "SELECT id FROM t WHERE col REGEXP '{.*{'" > bad.txt selects all the rows that will need this substitution. How do I make this substitution very quickly? EDIT: Could I do it by update table set column = REPLACE(column,'{',''); Then restore the out most pair update table set column = REPLACE(column,'^','{'); update table set column = REPLACE(column,'$','}');

    Read the article

  • connecting to mysql from excel: ODBC driver does not support the requested properties.

    - by every_answer_gets_a_point
    i am trying to add data to mysql from excel. i am getting the above error on this line: rs.Open strSQL, oConn, adOpenDynamic, adLockOptimistic here is my code: Dim oConn As ADODB.Connection Private Sub ConnectDB() Set oConn = New ADODB.Connection oConn.Open "DRIVER={MySQL ODBC 5.1 Driver};" & _ "SERVER=localhost;" & _ "DATABASE=employees;" & _ "USER=root;" & _ "PASSWORD=some_pass;" & _ "Option=3" End Sub Function esc(txt As String) esc = Trim(Replace(txt, "'", "\'")) End Function Private Sub InsertData() Dim rs As ADODB.Recordset Set rs = New ADODB.Recordset ConnectDB With wsBooks For rowCursor = 2 To 11 strSQL = "INSERT INTO tutorial (author, title, price) " & _ "VALUES ('" & esc(.Cells(rowCursor, 1)) & "', " & _ "'" & esc(.Cells(rowCursor, 2)) & "', " & _ esc(.Cells(rowCursor, 3)) & ")" rs.Open strSQL, oConn, adOpenDynamic, adLockOptimistic Next End With End Sub whats wrong with rs.Open strSQL, oConn, adOpenDynamic, adLockOptimistic ? why am i getting the odbc error?

    Read the article

  • Naming of boolean column in database table

    - by Space Cracker
    I have 'Service' table and the following column description as below Is User Verification Required for service ? Is User's Email Activation Required for the service ? Is User's Mobile Activation required for the service ? I Hesitate in naming these columns as below IsVerificationRequired IsEmailActivationRequired IsMobileActivationRequired or RequireVerification RequireEmailActivation RequireMobileActivation I can't determined which way is the best .So, Is one of the above suggested name is the best or is there other better ones ?

    Read the article

  • How should I build a gaming community

    - by Przystojny
    I've been wanting to build my own gaming community site (like http://fragbite.com) for a long time, I have started many times but just quitted after a couple days because it gets very messy I've been palying around with php and mysql off and on for 3 years but i've never gotten in to oop. i have tried but i usually end up with the "old php". I usually build my pages like so that i include a file on top of all pages with neccasary functions, html head etc. And I mix php and html together which I dont mind but if I eventually would get a designer he would not like it i think. I have tried both phpcake and codeigniter and all those popular mvc's but its just to much, like they do all the work. i want to do it myself. but i dont know where to start. What would you do if you were me? Is there maybe some non-oop mvc? (Sorry for my english)

    Read the article

  • Oracle global_names DELETE problem

    - by jyzuz
    I'm using a database link to execute a DELETE statement on another DB, but the DB link name doesn't conform to global naming, and this requirement cannot change. Also I have global_names set to false, and cannot be changed either. When I try to use these links however, I receive: ORA-02069: - global_names parameter must be set to TRUE for this operation Cause: A remote mapping of the statement is required but cannot be achieved because GLOBAL_NAMES should be set to TRUE for it to be achieved. - Action: Issue `ALTER SESSION SET GLOBAL_NAMES = TRUE` (if possible) What is the alternative action when setting global_names=true is not possible? Cheers, Jean

    Read the article

  • CLR: Multi Param Aggregate, Argument not in Final Output?

    - by OMG Ponies
    Why is my delimiter not appearing in the final output? It's initialized to be a comma, but I only get ~5 white spaces between each attribute using: SELECT [article_id] , dbo.GROUP_CONCAT(0, t.tag_name, ',') AS col FROM [AdventureWorks].[dbo].[ARTICLE_TAG_XREF] atx JOIN [AdventureWorks].[dbo].[TAGS] t ON t.tag_id = atx.tag_id GROUP BY article_id The bit for DISTINCT works fine, but it operates within the Accumulate scope... Output: article_id | col ------------------------------------------------- 1 | a a b c I only have rudimentary C# API knowledge... C# Code: using System; using System.Data; using System.Data.SqlClient; using System.Data.SqlTypes; using Microsoft.SqlServer.Server; using System.Xml.Serialization; using System.Xml; using System.IO; using System.Collections; using System.Text; [Serializable] [SqlUserDefinedAggregate(Format.UserDefined, MaxByteSize = 8000)] public struct GROUP_CONCAT : IBinarySerialize { ArrayList list; string delimiter; public void Init() { list = new ArrayList(); delimiter = ","; } public void Accumulate(SqlBoolean isDistinct, SqlString Value, SqlString separator) { delimiter = (separator.IsNull) ? "," : separator.Value ; if (!Value.IsNull) { if (isDistinct) { if (!list.Contains(Value.Value)) { list.Add(Value.Value); } } else { list.Add(Value.Value); } } } public void Merge(GROUP_CONCAT Group) { list.AddRange(Group.list); } public SqlString Terminate() { string[] strings = new string[list.Count]; for (int i = 0; i < list.Count; i++) { strings[i] = list[i].ToString(); } return new SqlString(string.Join(delimiter, strings)); } #region IBinarySerialize Members public void Read(BinaryReader r) { int itemCount = r.ReadInt32(); list = new ArrayList(itemCount); for (int i = 0; i < itemCount; i++) { this.list.Add(r.ReadString()); } } public void Write(BinaryWriter w) { w.Write(list.Count); foreach (string s in list) { w.Write(s); } } #endregion }

    Read the article

  • Bulk Compare, Report, Update

    - by Tim Donaldon
    I need to import either csv or excel file into a dbase. The column headers will match but I will want to compare the file against the dbase using an ItemID field, list the rows to be affected and the differences, then allow an update to all the rows with the matching ID.

    Read the article

  • count(*) vs count(row-name) - which is more correct?

    - by bread
    Does it make a difference if you do count(*) vs count(row-name) as in these two examples? I have a tendency to always write count(*) because it seems to fit better in my mind with the notion of it being an aggregate function, if that makes sense. But I'm not sure if it's technically best as I tend to see example code written without the * more often than not. count(*): select customerid, count(*), sum(price) from items_ordered group by customerid having count(*) > 1; vs. count(row-name): SELECT customerid, count(customerid), sum(price) FROM items_ordered GROUP BY customerid HAVING count(customerid) > 1;

    Read the article

  • What's the best way to access a MS Access database using PHP?

    - by Jack Roscoe
    Hi, I need to access some data from an MS Access database and retrieve some data from it using PHP. I've looked around the web, and found the following line which seems to correctly connect to the database: $conn->Open("DRIVER={Microsoft Access Driver (*.mdb)}; DBQ=C:\wamp\www\data\MYDB.mdb"); However, I have tried to retrieve some data in the following way: $query = "SELECT pageid FROM pages_table"; $result = mysqli_query($conn, $query); $amount_of_pages = 0; if(mysqli_num_rows($result) <= 0) echo "No results found."; else while($row = mysqli_fetch_array($result, MYSQL_ASSOC)) $amount_of_pages++; And was presented with the following errors: Warning: mysqli_query() expects parameter 1 to be mysqli, object given in C:\wamp\www\data\index.php on line 19 Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, null given in C:\wamp\www\data\index.php on line 23 No results found. I don't really understand the connection to the Access database, is there something I should be doing differently? Thanks in advance for any help.

    Read the article

  • 100+ tables to joined

    - by deian
    Hi guys, I was wondering if anyone ever had a change to measure how a would 100 joined tables perform? Each table would have an ID column with primary index and all table are 1:1 related. It is a common problem within many data entry applications where we need to collect 1000+ data points. One solution would be to have one big table with 1000+ columns and the alternative would be to split them into multiple tables and join them when it is necessary. So perhaps more real question would be how 30 tables (30 columns each) would behave with multitable join. 500K-1M rows should be the expected size of the tables. Cheers

    Read the article

  • Index for wildcard match of end of string

    - by Anders Abel
    I have a table of phone numbers, storing the phone number as varchar(20). I have a requirement to implement searching of both entire numbers, but also on only the last part of the number, so a typical query will be: SELECT * FROM PhoneNumbers WHERE Number LIKE '%1234' How can I put an index on the Number column to make those searchs efficient? Is there a way to create an index that sorts the records on the reversed string? Another option might be to reverse the numbers before storing them, which will give queries like: SELECT * FROM PhoneNumbers WHERE ReverseNumber LIKE '4321%' However that will require all users of the database to always reverse the string. It might be solved by storing both the normal and reversed number and having the reversed number being updated by a trigger on insert/update. But that kind of solution is not very elegant. Any other suggestions?

    Read the article

  • move data from one table to another, postgresql edition

    - by IggShaman
    Hi All, I'd like to move some data from one table to another (with a possibly different schema). Straightforward solution that comes into mind is - start a transaction with serializable isolation level; INSERT INTO dest_table SELECT data FROM orig_table,other-tables WHERE <condition>; DELETE FROM orig_table USING other-tables WHERE <condition>; COMMIT; Now what if the amount of data is rather big, and the <condition> is expensive to compute? In PostgreSQL, a RULE or a stored procedure can be used to delete data on the fly, evaluating condition only once. Which solution is better? Are there other options?

    Read the article

  • Generating a set of files containing dumps of individual tables in a way that guarantees database co

    - by intuited
    I'd like to dump a MySQL database in such a way that a file is created for the definition of each table, and another file is created for the data in each table. I'd like this to be done in a way that guarantees database integrity by locking the entire database for the duration of the dump. What is the best way to do this? Similarly, what's the best way to lock the database while restoring a set of these dump files? edit I can't assume that mysql will have permission to write to files.

    Read the article

  • Can't delete record via the datacontext it was retrieved from

    - by Antilogic
    I just upgraded one of my application's methods to use compiled queries (not sure if this is relevant). Now I'm getting contradicting error messages when I run the code. This is my method: MyClass existing = Queries.MyStaticCompiledQuery(MyRequestScopedDataContext, param1, param2).SingleOrDefault(); if (existing != null) { MyRequestScopedDataContext.MyClasses.DeleteOnSubmit(existing); } When I run it I get this message: Cannot remove an entity that has not been attached. Note that the compiled query and the DeleteOnSubmit reference the same DataContext. Still I figured I'd humor the application and add an attach command before the DeleteOnSubmit, like so: MyClass existing = Queries.MyStaticCompiledQuery(MyRequestScopedDataContext, param1, param2).SingleOrDefault(); if (existing != null) { MyRequestScopedDataContext.MyClasses.Attach(existing); MyRequestScopedDataContext.MyClasses.DeleteOnSubmit(existing); } BUT... When I run this code, I get a completely different contradictory error message: An attempt has been made to Attach or Add an entity that is not new, perhaps having been loaded from another DataContext. This is not supported. I'm at a complete loss... Does anyone else have some insight as to why I can't delete a record via the same DataContext I retrieved it from?

    Read the article

  • Subquery with multiple results combined into a single field?

    - by Todd
    Assume I have these tables, from which i need to display search results in a browser: Table: Containers id | name 1 Big Box 2 Grocery Bag 3 Envelope 4 Zip Lock Table: Sale id | date | containerid 1 20100101 1 2 20100102 2 3 20091201 3 4 20091115 4 Table: Items id | name | saleid 1 Barbie Doll 1 2 Coin 3 3 Pop-Top 4 4 Barbie Doll 2 5 Coin 4 I need output that looks like this: itemid itemname saleids saledates containerids containertypes 1 Barbie Doll 1,2 20100101,20100102 1,2 Big Box, Grocery Bag 2 Coin 3,4 20091201,20091115 3,4 Envelope, Zip Lock 3 Pop-Top 4 20091115 4 Zip Lock The important part is that each item type only gets one record/row in the return on the screen. I accomplished this in the past by returning multiple rows of the same item and using a scripting language to limit the output. However, this makes the ui overly complicated and loopy. So, I'm hoping I can get the database to spit out only as many records as there are rows to display. This example may be a bit extreme because of the 2 joins needed to get to the container from the item (through the sale table). I'd be happy for just an example query that outputs this: itemid itemname saleids saledates 1 Barbie Doll 1,2 20100101,20100102 2 Coin 3,4 20091201,20091115 3 Pop-Top 4 20091115 I can only return a single result in a subquery, so I'm not sure how to do this.

    Read the article

  • How efficient is a details table?

    - by Jeffrey Lott
    At my job, we have pseudo-standard of creating one table to hold the "standard" information for an entity, and a second table, named like 'TableNameDetails', which holds optional data elements. On average, for every row in the main table will have about 8-10 detail rows in it. My question is: What kind of performance impacts does this have over adding these details as additional nullable columns on the main table?

    Read the article

  • MySQL Query to find consecutive available times of variable lenth

    - by Armaconn
    I have an events table that has user_id, date ('2013-10-01'), time ('04:15:00'), and status_id; What I am looking to find is a solution similar to http://stackoverflow.com/questions/2665574/find-consecutive-rows-calculate-duration but I need I need two additional components: 1) Take date into consideration, so 10/1/2013 at 11:00 PM - 10/2/2013 at 3:00AM. Feel free to just put in a fake date range (like '2013-10-01' to '2013-10-31') 2) Limit output to only include when there are 4+ consecutive times (each event is 15 minutes and I want it to display minimum blocks of an hour, but would also like to be able to switch this restriction to 1.5 hours or some other duration if possible). SUMMARY - Looking for a query that provides the start and end times for a set of events that have the same user_id, status_id, and are in a continuous series based on date and time. For which I can restrict results based on date range and minimum series duration. So the output should have: user_id, date_start, time_start, date_end, time_end, status_id, duration CREATE TABLE `events` ( `event_id` int(11) NOT NULL auto_increment COMMENT 'ID', `user_id` int(11) NOT NULL, `date` date NOT NULL, `time` time NOT NULL, `status_id` int(11) default NULL, PRIMARY KEY (`event_id`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=1568 ; INSERT INTO `events` VALUES(1, 101, '2013-08-14', '23:00:00', 2); INSERT INTO `events` VALUES(2, 101, '2013-08-14', '23:15:00', 2); INSERT INTO `events` VALUES(3, 101, '2013-08-14', '23:30:00', 2); INSERT INTO `events` VALUES(4, 101, '2013-08-14', '23:45:00', 2); INSERT INTO `events` VALUES(5, 101, '2013-08-15', '00:00:00', 2); INSERT INTO `events` VALUES(6, 101, '2013-08-15', '00:15:00', 1); INSERT INTO `events` VALUES(7, 500, '2013-08-14', '23:45:00', 1); INSERT INTO `events` VALUES(8, 500, '2013-08-15', '00:00:00', 1); INSERT INTO `events` VALUES(9, 500, '2013-08-15', '00:15:00', 2); INSERT INTO `events` VALUES(10, 500, '2013-08-15', '00:30:00', 2); INSERT INTO `events` VALUES(11, 500, '2013-08-15', '00:45:00', 1); Desired output row |user_id | date_start | time_start | date_end | time_end | status_id | duration 1 |101 |'2013-08-14'| '23:00:00' |'2013-08-15'|'00:15:00'| 2 | 5 2 |101 |'2013-08-15'| '00:00:15' |'2013-08-15'|'00:30:00'| 1 | 1 3 |500 |'2013-08-14'| '00:23:45' |'2013-08-15'|'00:15:00'| 1 | 2 4 |500 |'2013-08-15'| '00:00:15' |'2013-08-15'|'00:45:00'| 2 | 2 5 |500 |'2013-08-15'| '00:00:45' |'2013-08-15'|'01:00:00'| 2 | 1 *except that rows 2 and 5 wouldn't appear if duration had to be greater than 30 minutes Thanks for any help that you can provide! And please let me know if there is anything I can further clarify!!

    Read the article

  • possible way to attach database to exe

    - by ali
    i created a small application using c# winforms that uses mssql as a database. is there a way to attach the database to the exe file so i won't need to install sqlserver on all the machines that i want to run the program on?

    Read the article

< Previous Page | 647 648 649 650 651 652 653 654 655 656 657 658  | Next Page >