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  • Column break in word - continously

    - by Holian
    Masters, I need to PASTE my content in two different column in word. (I have 300 page of old content and 300 page of new content, i want to share my partners this information side by side to compare) I made two column and instert a column break, but i have to insert column break every page? How can i do this easier? Any way to insert column break continously, so i just need to copy&paste the contents into the columns? thank you

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  • What is the best approach for database design with lots of columns?

    - by Pratyush
    I am writing a query based financial application. It lets the user to write complicated equations (much like WHERE part of an SQL query) and find companies matching those criteria. For the above, I currently have more than 500 columns in the database table (each column representing a financial field). Example of Columns are: company_name, sales_annual_00, sales_annual_01, sales_annual_02, sales_annual_03, sales_annual_04, protit_annual_00, profit_annual1...(over 500 such columns). The number of rows is around 5000. Going forward, I would like to further increase the number of columns/financial-fields. For the above I would like to get help regarding: 1) What is the best database design approach? Is it ok to have these many number of columns? 2) How can it be normalized? (User can use any of these fields in search criteria). 3) Is it ok to stick with MySQL, or modern document based databases like MongoDB should be better for it? P.S. (Update): I have been using MySQL till now and a running example of the usage is at: http://screener.in/companies/89/Formula-- In above there around 500 fields/columns to create your query on, however, I seek to increase that number to much more in future.

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  • SQL Server pivots? some way to set column names to values within a row

    - by ccsimpson3
    I am building a system of multiple trackers that are going to use a lot of the same columns so there is a table for the trackers, the tracker columns, then a cross reference for which columns go with which tracker, when a user inserts a tracker row the different column values are stored in multiple rows that share the same record id and store both the value and the name of the particular column. I need to find a way to dynamically change the column name of the value to be the column name that is stored in the same row. i.e. id | value | name ------------------ 23 | red | color 23 | fast | speed needs to look like this. id | color | speed ------------------ 23 | red | fast Any help is greatly appreciated, thank you.

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  • SQL: How to use a column that was just added

    - by sbenderli
    I am trying to add 2 columns and then I would like to set some values to them but I get a compile-error saying the column does not exist. I am using the following script: IF NOT EXISTS (select column_name from INFORMATION_SCHEMA.columns where table_name = 'SYSTM_FRM' and column_name = 'SF_Ip_TXT') ALTER TABLE SYSTM_FRM add SF_Ip_TXT NVARCHAR(20) IF NOT EXISTS (select column_name from INFORMATION_SCHEMA.columns where table_name = 'SYSTM_FRM' and column_name = 'SF_Port_NUM') ALTER TABLE SYSTM_FRM add SF_Port_NUM int Update dbo.SYSTM_FRM SET dbo.SYSTM_FRM.SF_Ip_TXT = dbo.FRM.FRM_Ip_TXT, dbo.SYSTM_FRM.SF_Port_NUM = dbo.FRM.FRM_Port_NUM FROM dbo.FRM INNER JOIN dbo.SYSTM_FRM ON dbo.FRM.FRM_RCRD_NUM = dbo.SYSTM_FRM.SF_FrameRecord_NUM Is there any way to use a column that I am adding in the same script?

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  • jQuery Columnizer plugin only working correctly on window resize.

    - by rcon
    Hi, I'm using the jQuery Columnizer plugin, and I'm running into a weird problem. Using 3 columns, I columnize content from a hidden div into a target div. It distributes only one paragraph to each of the first two columns and then puts all the remaining paragraphs into the last column. But the strange thing is that it auto-corrects itself when the window is resized. I'm guessing it has something to do with the target div resizing since opening a firebug console window also causes it to auto-correct itself. Setting lastNeverTallest:true doesn't seem to do anything. $('#hidden-about').columnize({ columns: 3, target: '#interiors', lastNeverTallest: true, doneFunc: function() { $('#interiors').css('white-space', 'normal'); $('#interiors').fadeIn(200); } Thanks for any suggestions!

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  • conditional formatting for subsequent rows or columns

    - by Trailokya Saikia
    I have data in a range of cells (say six columns and one hundred rows). The first four column contains data and the sixth column has a limiting value. For data in every row the limiting value is different. I have one hundred such rows. I am successfully using Conditional formatting (e.g. cells containing data less than limiting value in first five columns are made red) for 1st row. But how to copy this conditional formatting so that it is applicable for entire hundred rows with respective limiting values. I tried with format painter. But it retains the same source cell (here limiting value) for the purpose of conditional formatting in second and subsequent rows. So, now I am required to use conditional formatting for each row separately s

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  • Cant Add Columns to a AD Task pad except for the top level of the domain

    - by Darktux
    We are working on Active Directory taskpads application for user management in our organization and facing stange issue. When we create a taskpad, and when we are at top level of the domain, i can click view - Add/Remove Columns and add "Pre Windows Name" (and lots of other properties) to the taskpad as columns, but when i just go 1 level down , i can only see "Operating System" and "Service Pack" ; why is it happening , isnt "Domain Admins" supposed to god access to all the things in AD domain , atleast of objects they own? It is important to have "Pre Windows 2000" Name as a column begause with out that our "Shell Command" task wont show up in taskpads, since its bound to parameter "Col<9" (which is pre qindows name). Please do let me know if any additions questions to clarify my problem.

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  • I see no LOBs!

    - by Paul White
    Is it possible to see LOB (large object) logical reads from STATISTICS IO output on a table with no LOB columns? I was asked this question today by someone who had spent a good fraction of their afternoon trying to work out why this was occurring – even going so far as to re-run DBCC CHECKDB to see if any corruption had taken place.  The table in question wasn’t particularly pretty – it had grown somewhat organically over time, with new columns being added every so often as the need arose.  Nevertheless, it remained a simple structure with no LOB columns – no TEXT or IMAGE, no XML, no MAX types – nothing aside from ordinary INT, MONEY, VARCHAR, and DATETIME types.  To add to the air of mystery, not every query that ran against the table would report LOB logical reads – just sometimes – but when it did, the query often took much longer to execute. Ok, enough of the pre-amble.  I can’t reproduce the exact structure here, but the following script creates a table that will serve to demonstrate the effect: IF OBJECT_ID(N'dbo.Test', N'U') IS NOT NULL DROP TABLE dbo.Test GO CREATE TABLE dbo.Test ( row_id NUMERIC IDENTITY NOT NULL,   col01 NVARCHAR(450) NOT NULL, col02 NVARCHAR(450) NOT NULL, col03 NVARCHAR(450) NOT NULL, col04 NVARCHAR(450) NOT NULL, col05 NVARCHAR(450) NOT NULL, col06 NVARCHAR(450) NOT NULL, col07 NVARCHAR(450) NOT NULL, col08 NVARCHAR(450) NOT NULL, col09 NVARCHAR(450) NOT NULL, col10 NVARCHAR(450) NOT NULL, CONSTRAINT [PK dbo.Test row_id] PRIMARY KEY CLUSTERED (row_id) ) ; The next script loads the ten variable-length character columns with one-character strings in the first row, two-character strings in the second row, and so on down to the 450th row: WITH Numbers AS ( -- Generates numbers 1 - 450 inclusive SELECT TOP (450) n = ROW_NUMBER() OVER (ORDER BY (SELECT 0)) FROM master.sys.columns C1, master.sys.columns C2, master.sys.columns C3 ORDER BY n ASC ) INSERT dbo.Test WITH (TABLOCKX) SELECT REPLICATE(N'A', N.n), REPLICATE(N'B', N.n), REPLICATE(N'C', N.n), REPLICATE(N'D', N.n), REPLICATE(N'E', N.n), REPLICATE(N'F', N.n), REPLICATE(N'G', N.n), REPLICATE(N'H', N.n), REPLICATE(N'I', N.n), REPLICATE(N'J', N.n) FROM Numbers AS N ORDER BY N.n ASC ; Once those two scripts have run, the table contains 450 rows and 10 columns of data like this: Most of the time, when we query data from this table, we don’t see any LOB logical reads, for example: -- Find the maximum length of the data in -- column 5 for a range of rows SELECT result = MAX(DATALENGTH(T.col05)) FROM dbo.Test AS T WHERE row_id BETWEEN 50 AND 100 ; But with a different query… -- Read all the data in column 1 SELECT result = MAX(DATALENGTH(T.col01)) FROM dbo.Test AS T ; …suddenly we have 49 LOB logical reads, as well as the ‘normal’ logical reads we would expect. The Explanation If we had tried to create this table in SQL Server 2000, we would have received a warning message to say that future INSERT or UPDATE operations on the table might fail if the resulting row exceeded the in-row storage limit of 8060 bytes.  If we needed to store more data than would fit in an 8060 byte row (including internal overhead) we had to use a LOB column – TEXT, NTEXT, or IMAGE.  These special data types store the large data values in a separate structure, with just a small pointer left in the original row. Row Overflow SQL Server 2005 introduced a feature called row overflow, which allows one or more variable-length columns in a row to move to off-row storage if the data in a particular row would otherwise exceed 8060 bytes.  You no longer receive a warning when creating (or altering) a table that might need more than 8060 bytes of in-row storage; if SQL Server finds that it can no longer fit a variable-length column in a particular row, it will silently move one or more of these columns off the row into a separate allocation unit. Only variable-length columns can be moved in this way (for example the (N)VARCHAR, VARBINARY, and SQL_VARIANT types).  Fixed-length columns (like INTEGER and DATETIME for example) never move into ‘row overflow’ storage.  The decision to move a column off-row is done on a row-by-row basis – so data in a particular column might be stored in-row for some table records, and off-row for others. In general, if SQL Server finds that it needs to move a column into row-overflow storage, it moves the largest variable-length column record for that row.  Note that in the case of an UPDATE statement that results in the 8060 byte limit being exceeded, it might not be the column that grew that is moved! Sneaky LOBs Anyway, that’s all very interesting but I don’t want to get too carried away with the intricacies of row-overflow storage internals.  The point is that it is now possible to define a table with non-LOB columns that will silently exceed the old row-size limit and result in ordinary variable-length columns being moved to off-row storage.  Adding new columns to a table, expanding an existing column definition, or simply storing more data in a column than you used to – all these things can result in one or more variable-length columns being moved off the row. Note that row-overflow storage is logically quite different from old-style LOB and new-style MAX data type storage – individual variable-length columns are still limited to 8000 bytes each – you can just have more of them now.  Having said that, the physical mechanisms involved are very similar to full LOB storage – a column moved to row-overflow leaves a 24-byte pointer record in the row, and the ‘separate storage’ I have been talking about is structured very similarly to both old-style LOBs and new-style MAX types.  The disadvantages are also the same: when SQL Server needs a row-overflow column value it needs to follow the in-row pointer a navigate another chain of pages, just like retrieving a traditional LOB. And Finally… In the example script presented above, the rows with row_id values from 402 to 450 inclusive all exceed the total in-row storage limit of 8060 bytes.  A SELECT that references a column in one of those rows that has moved to off-row storage will incur one or more lob logical reads as the storage engine locates the data.  The results on your system might vary slightly depending on your settings, of course; but in my tests only column 1 in rows 402-450 moved off-row.  You might like to play around with the script – updating columns, changing data type lengths, and so on – to see the effect on lob logical reads and which columns get moved when.  You might even see row-overflow columns moving back in-row if they are updated to be smaller (hint: reduce the size of a column entry by at least 1000 bytes if you hope to see this). Be aware that SQL Server will not warn you when it moves ‘ordinary’ variable-length columns into overflow storage, and it can have dramatic effects on performance.  It makes more sense than ever to choose column data types sensibly.  If you make every column a VARCHAR(8000) or NVARCHAR(4000), and someone stores data that results in a row needing more than 8060 bytes, SQL Server might turn some of your column data into pseudo-LOBs – all without saying a word. Finally, some people make a distinction between ordinary LOBs (those that can hold up to 2GB of data) and the LOB-like structures created by row-overflow (where columns are still limited to 8000 bytes) by referring to row-overflow LOBs as SLOBs.  I find that quite appealing, but the ‘S’ stands for ‘small’, which makes expanding the whole acronym a little daft-sounding…small large objects anyone? © Paul White 2011 email: [email protected] twitter: @SQL_Kiwi

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  • Mac Excel 2011: find Items in one column that are not in another column

    - by robert-jakobson
    Hi this is a repeat of the question: Excel: Find Items in one column that are not in another column I have two columns in excel, and I want to find (preferably highlight) the items that are in column B, but not in column A. What's the quickest way to do this? However, the answer given below to in the above-menitoned thread no longer applies to Mac Excel 2011. E.g. there is no "name-a-range" option available on right click etc.. Therefore I am asking this again. Select the list in column A Right-Click and select Name a Range... Enter "ColumnToSearch" Click cell C1 Enter this formula: =MATCH(B1,ColumnToSearch,0) Drag the formula down for all items in B If the formula fails to find a match, it will be marked #N/A, otherwise it will be a number. If you'd like it to be TRUE for match and FALSE for no match, use this formula instead: =IF(ISNA(MATCH(B1,ColumnToSearch,0)),FALSE,TRUE) How should this answer be restated to apply to Mac Excel 2011?

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  • Select distinct from multiple fields using sql

    - by Bryan
    I have 5 columns corresponding to answers in a trivia game database - right, wrong1, wrong2, wrong3, wrong4 I want to return all possible answers without duplicates. I was hoping to accomplish this without using a temp table. Is it possible to use something similar to this?: select c1, c2, count(*) from t group by c1, c2 But this returns 3 columns. I would like one column of distinct answers. Thanks for your time

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  • Computed column should result to string

    - by strakastroukas
    Here is a snap of my database. Both col1 and col2 are declared as int. My ComputedColumn currently adds the Columns 1 and 2, as follows... col1 col2 ComputedColumn 1 2 3 4 1 5 Instead of this, my ComputedColumn should join the columns 1 and 2 (includimg the '-' character in the middle) as follows... col1 col2 ComputedColumn 1 2 1-2 4 1 4-1 So, what is the correct syntax?

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  • No cursor when resizing datagridview

    - by anya
    When i'm trying to resize datagridview columns the resize cursor appears only when i roll over header. However, when i roll over in between cells, resize cursor doesn't show at all. I have noticed if i set ColumnHeadersVisible = false it fixes the problem and i see resize cursor between columns. However, i need header to be visible, any idea how to make it work all together?

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  • No cursor when resizing datagridview c#

    - by anya
    HI guys, When im trying to resize datagridview columns the resize cursor appears only when i roll over header. However, when i roll over in between cells, resize cursor doesnt show at all. I have noticed if i set ColumnHeadersVisible = false it fixes the problem and i see resize cursor between columns. However, i need header to be visible, any idea how to make it work all together? Thanks!

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  • How to get number of attributes in a java class?

    - by llm
    I have a java class containing all the columns of a database table as attributes (member variables) and corresponding getters and setters. I want to have a method in this class called getColumnCount() that returns the number of columns (i.e. the number of attributes in the class)? How would I implement this without hardcoding the number? I am open to critisims on this in general and suggestions. Thanks.

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  • Finding matching columns in excel

    - by fakaff
    I've never used excel before so I need the simplest solution available, and this is a work assignment due this week so I didn't have time read much of the documentation. Basically, I have two tables, A and B, and they are both thousands of rows long. Description of my task: right now (since I don't know better) I'm manually doing this: Go to row i in table B. Select entries in columns B(a, b, c) of that same row. Look for a row in table A where column A(b) matches row B(a). Paste the entries of columns B(a) of row i at the end of the row found in the last step. Repeat for row i + 1. Example: row B(cat, dog, mouse) matches A(mammal, cat, Mr. Whiskers). So I would paste B after A and have A(mammal, cat, Mr. Whiskers, cat, dog, mouse). Note: I am not joining tables. I am merely extending table A by pasting row A(b) if row A(b) matches row B(a). Also, sometimes entries are spelled slightly differently. Using wildcards to search for candidates would be of help. As the description should let on, this task is very tedious and inefficient if I don't know how to automate some operations (there are thousands of entries). Any quick tips as to how to be more productive is a big help.

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  • Need an Overview of Possibilities for multicolumn programming

    - by Sam
    Hi folks, From source1 and source2 i gather that IE9 will NOT support multi-column css3!! Since it is still the most popular browser (another thing i cannot understand), i am left but no other choice than to use Programming Power to make multi-columns work. Now, I use three divs that float to left, and which are manually filled with text. Please don't laugh i know its stupid! But I would wish to not to have to worry about the columns and just have a one piece of (un-interrupted) text which all goes into only 1 div, and then have a program smart enough to split it up into X equally wide columns. Question: before i start reinvent the wheel, what methods of programming power have you known that tackle this elegantly? Please suggest your best working multi-column layout sources so I can evaluate which option is the best (I will update the below table). Exploring all possibilities 2011 and further, to enable multi column text user experience: Language Author SourceCodeUsage WorksOnAllMajorBrowser? ================================================================================= html manual labour put text manually in separate left-floating divs "Y" // Upside: control! Downside: few changes necessitates to reflow 3 divs manually! CSS3 w3c css3.info/preview/multi-column-layout/ "N" // {-moz-column-count: 3; -webkit-column-count: 3; } Thats all! javascript a list apart will add url soon ? // php ? ? ? //

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  • What Are The Ways to Devide Text in Multi-Column? Need an Overview of Possibilities.

    - by Sam
    Hi folks, From source1 and source2 i gather that IE9 will NOT support multi-column css3!! Since it is still the most popular browser (another thing i cannot understand), i am left but no other choice than to use Programming Power to make multi-columns work. Now, I use three divs that float to left, and which are manually filled with text. Please don't laugh i know its stupid! But I would wish to not to have to worry about the columns and just have a one piece of (un-interrupted) text which all goes into only 1 div, and then have a program smart enough to split it up into X equally wide columns. Question: before i start reinvent the wheel, what methods of programming power have you known that tackle this elegantly? Please suggest your best working multi-column layout sources so I can evaluate which option is the best (I will update the below table). Exploring all possibilities 2011 and further, to enable multi column text user experience: Language Author SourceCodeUsage WorksOnAllMajorBrowser? ================================================================================= html manual labour put text manually in separate left-floating divs "Y" // Upside: control! Downside: few changes necessitates to reflow 3 divs manually! CSS3 w3c css3.info/preview/multi-column-layout/ "N" // {-moz-column-count: 3; -webkit-column-count: 3; } Thats all! javascript a list apart will add url soon ? // php ? ? ? //

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  • 2-column table with two foreign keys. Performance/design question.

    - by Emanuel
    Hello everyone! I recently ran into a quite complex problem and after looking around a lot I couldn't find a solution to it. I've found answers to my questions many times before on stackoverflow.com, so I decided to post here. So I'm making a user/group managment system for a web-based project, and I'm storing all related data into a postgreSQL database. This system relies on three tables: USERS GROUPS GROUP_USERS The two first tables simply define all the users and all the groups on the site, and the last table, GROUP_USERS, stores the groups every user is part of. It only has two columns: USER_ID GROUP_ID Since every user can be a member of several groups, I decided to make a separate table for this purpose, rather than storing a comma separated column in the USERS-table. Now, both columns are foreign keys, and I want to make them both primary keys as well, this since each combination of USER_ID and GROUP_ID has to be unique, and if I give them the constraint UNIQUE pgAdmin tells me that each table should have at least one Primary key. But now I am stuck with what seems to be a lot of indexes and relations to a very small table only containing numbers. In the end, I want this table to be as fast as possible, even if containing tens of thousands of rows. Size on disk shouldn't be a problem since its just all numbers anyway, but it feels quite stupid to have a full-sized index refering to a smaller table. Should I stick with my current solution, store comma-separated values in a column in the USERS-table or is there any other solution I should be aware of. PS. I don't want to use an array-column, even if they are supported by postgreSQL. I want to be as generic as possible so I can switch database later on, if necessary. EDIT: I other words, will using a compound primary key and two foreign keys in one table with only two columns have a negative impact on performance rather than the opposite due to the size of the generated index? Thank you!

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  • Making Infragistics ultrawingrid, desired columns readonly

    - by Amit Ranjan
    I am stucked at the situation where I need to disable few columns of a each row ,except newly added row. That is I have 10 columns in grid and I want first three columns that are binded from the rows coming from db as disabled or read-only, rest are editable. if I add new row then all columns of new row must be enabled until and unless it is saved. I dont have any DataKey or Primary key for my existing row or new row. I have to check for some boolean values like IsNewRow. in my current scenario i am using this code block Private Sub dgTimeSheet_InitializeRow(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinGrid.InitializeRowEventArgs) Handles dgTimeSheet.InitializeRow ''if either column key is Project, Class or Milestone '' Activation.NoEdit = Disable and Activation.AllowEdit = Enable Dim index As Integer = e.Row.Index If e.Row.IsAddRow Then dgTimeSheet.Rows(index).Cells(PROJECT).Activation = Activation.AllowEdit dgTimeSheet.Rows(index).Cells(SERVICE_ISSUE_CLASS).Activation = Activation.AllowEdit dgTimeSheet.Rows(index).Cells(MILESTONE).Activation = Activation.AllowEdit Else dgTimeSheet.Rows(index).Cells(PROJECT).Activation = Activation.NoEdit dgTimeSheet.Rows(index).Cells(SERVICE_ISSUE_CLASS).Activation = Activation.NoEdit dgTimeSheet.Rows(index).Cells(MILESTONE).Activation = Activation.NoEdit End If CheckRows() End Sub but the problem is that if i click on disabled/readonly rows then newly added rows also gets disabled., which i dont want

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  • Parsing large delimited files with dynamic number of columns

    - by annelie
    Hi, What would be the best approach to parse a delimited file when the columns are unknown before parsing the file? The file format is Rightmove v3 (.blm), the structure looks like this: #HEADER# Version : 3 EOF : '^' EOR : '~' #DEFINITION# AGENT_REF^ADDRESS_1^POSTCODE1^MEDIA_IMAGE_00~ // can be any number of columns #DATA# agent1^the address^the postcode^an image~ agent2^the address^the postcode^^~ // the records have to have the same number of columns as specified in the definition, however they can be empty etc #END# The files can potentially be very large, the example file I have is 40Mb but they could be several hundred megabytes. Below is the code I had started on before I realised the columns were dynamic, I'm opening a filestream as I read that was the best way to handle large files. I'm not sure my idea of putting every record in a list then processing is any good though, don't know if that will work with such large files. List<string> recordList = new List<string>(); try { using (FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read)) { StreamReader file = new StreamReader(fs); string line; while ((line = file.ReadLine()) != null) { string[] records = line.Split('~'); foreach (string item in records) { if (item != String.Empty) { recordList.Add(item); } } } } } catch (FileNotFoundException ex) { Console.WriteLine(ex.Message); } foreach (string r in recordList) { Property property = new Property(); string[] fields = r.Split('^'); // can't do this as I don't know which field is the post code property.PostCode = fields[2]; // etc propertyList.Add(property); } Any ideas of how to do this better? It's C# 3.0 and .Net 3.5 if that helps. Thanks, Annelie

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  • Python DictReader - Skipping rows with missing columns?

    - by victorhooi
    heya, I have a Excel .CSV file I'm attempting to read in with DictReader. All seems to be well, except it seems to omit rows, specifically those with missing columns. Our input looks like: mail,givenName,sn,lorem,ipsum,dolor,telephoneNumber [email protected],ian,bay,3424,8403,2535,+65(2)34523534545 [email protected],mike,gibson,3424,8403,2535,+65(2)34523534545 [email protected],ross,martin,,,,+65(2)34523534545 [email protected],david,connor,,,,+65(2)34523534545 [email protected],chris,call,3424,8403,2535,+65(2)34523534545 So some of the rows have missing lorem/ipsum/dolor columns, and it's just a string of commas for those. We're reading it in with: def read_gd_dump(input_file="blah 20100423.csv"): gd_extract = csv.DictReader(open('blah 20100423.csv'), restval='missing', dialect='excel') return dict([(row['something'], row) for row in gd_extract]) And I checked that "something" (the key for our dict) isn't one of the missing columns, I had originally suspected it might be that. It's one of the columns after that. However, DictReader seems to completely skip over the rows. I tried setting restval to something, didn't seem to make any difference. I can't seem to find anything in Python's CSV docs (http://docs.python.org/library/csv.html) that would explain this behaviour, but I may have misread something. Any ideas? Thanks, Victor

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  • mysql: Average over multiple columns in one row, ignoring nulls

    - by Sai Emrys
    I have a large table (of sites) with several numeric columns - say a through f. (These are site rankings from different organizations, like alexa, google, quantcast, etc. Each has a different range and format; they're straight dumps from the outside DBs.) For many of the records, one or more of these columns is null, because the outside DB doesn't have data for it. They all cover different subsets of my DB. I want column t to be their weighted average (each of a..f have static weights which I assign), ignoring null values (which can occur in any of them), except being null if they're all null. I would prefer to do this with a simple SQL calculation, rather than doing it in app code or using some huge ugly nested if block to handle every permutation of nulls. (Given that I have an increasing number of columns to average over as I add in more outside DB sources, this would be exponentially more ugly and bug-prone.) I'd use AVG but that's only for group by, and this is w/in one record. The data is semantically nullable, and I don't want to average in some "average" value in place of the nulls; I want to only be counting the columns for which data is there. Is there a good way to do this? Ideally, what I want is something like UPDATE sites SET t = AVG(a*a_weight,b*b_weight,...) where any null values are just ignored and no grouping is happening.

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  • Help on understanding multiple columns on an index?

    - by Xaisoft
    Assume I have a table called "table" and I have 3 columns, a, b, and c. What does it mean to have a non-clustered index on columns a,b? Is a nonclustered index on columns a,b the same as a nonclustered index on columns b,a? (Note the order). Also, Is a nonclustered index on column a the same as a nonclustered index on a,c? I was looking at the website sqlserver performance and they had these dmv scripts where it would tell you if you had overlapping indexes and I believe it was saying that having an index on a is the same as a,b, so it is redundant. Is this true about indexes? One last question is why is the clustered index put on the primary key. Most of the time the primary key is not queried against, so shouldn't the clustered index be on the most queried column. I am probably missing something here like having it on the primary key speeds up joins? Great explanations. Should I turn this into a wiki and change the title index explanation?

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  • R : remove columns from dataframe where ALL values are NA

    - by Sophomore
    hello everybody! I'm having some trouble with my huge data frame and couldn't really resolve that question myself: The dataframe has some properties as columns and each row represents one data set. I've done some sanatizing to this dataframe (e.g. get rid of datasets which are not to be included in evaluation). (Whoever might be interested: Beforehand I aggregate around 5000 single text files and put them in a tsv, some of the proerties have a sequence number like "button.pressed.1" ... ""button.pressed.n". Some of the sets excluded had really high numbers for n but got excluded, all sets left have much smaller numbers for n but the property "button.presed.50" is still there and all remaining sets have an NA in that column. Actually its a different property but the example should clarify my intention...) So the question is quite simple (for some sophisticated R pro): I need to get rid of columns where for ALL rows the value is NA. Could someone please help me out? (All I have managed to get rid of columns where at least one NA exists which dropped about half my columns)...

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  • SQL Structure of DB table with different types of columns

    - by Dmitry Dvornikov
    I have a problem with the optimization of the structure of the database. I'll try to explain it exactly. I create a project, where we can add different values??, but this values must have different types of the columns in the database (eg, int, double , varchar). What is the best way to store the different types of values ??in the database. In the project I'm using Propel 1.6. The point is availability to add value with 'int', 'varchar' and other columns types, to search the table was efficient. In total, I have two ideas. The first is to create a table of "value", which will have columns: "id ", "value_int", "value_double", "value_varchar", etc - with the corresponding column types. Depending on the type of values??, records will be saved with the value in the appropriate column (the rest will be NULL). The second solution is to create separate tables such as "value_int", "value_varchar" etc. There would be columns: "id", "value", which correspond to the relevant types of "value" (ie, such as int, varchar, etc). I must admit that I do not believe any of the above solutions, originally I was thinking about one table "value", where the column would be a "text" type - but this solution would probably be even worse. I would like to know your opinion on this topic, maybe something else would be better. Thanks in advance. EDIT: For example : We have three tables: USER: [table of users] * id * name FIELD: [table of profile fields - where the column 'type' is the type of field, eg int or varchar) * id * type * name VALUE : * id * User_id - ( FK user.id ) * Field_id - ( FK field.id ) * value So we have in each row an user in USER table, and the profile is stored in the VALUE table. Bit each profile field may have a different type (column 'type' in the FIELD table), and based on that I would want this value to add to the appropriate column of the appropriate type.

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