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  • How to differentiate two tables

    - by Nemat
    I have two tables and I want to get all records from one table that are different from the records in second table. Eg.: if we have four records in the first table like A,B,C,D and three records in the second table thats A,B,C then the answer of query should be D. I have tried "EXCEPT" operator but it doesn't work fine. Kindly help me in writing correct query for the given problem.

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  • Database design

    - by Hadad
    Hello, I've a system, that have two types of users (Companies and individuals).all types have a shared set of properties but they differ in another. What is the best design merge all in one table that allows null for unmatched properties, or separate them in two tables related to a basic table with a one to one relationship. Thanks.

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  • Query to bring count from comma seperated Value

    - by Mugil
    I have Two Tables One for Storing Products and Other for Storing Orders List. CREATE TABLE ProductsList(ProductId INT NOT NULL PRIMARY KEY, ProductName VARCHAR(50)) INSERT INTO ProductsList(ProductId, ProductName) VALUES(1,'Product A'), (2,'Product B'), (3,'Product C'), (4,'Product D'), (5,'Product E'), (6,'Product F'), (7,'Product G'), (8,'Product H'), (9,'Product I'), (10,'Product J'); CREATE TABLE OrderList(OrderId INT NOT NULL PRIMARY KEY AUTO_INCREMENT, EmailId VARCHAR(50), CSVProductIds VARCHAR(50)) SELECT * FROM OrderList INSERT INTO OrderList(EmailId, CSVProductIds) VALUES('[email protected]', '2,4,1,5,7'), ('[email protected]', '5,7,4'), ('[email protected]', '2'), ('[email protected]', '8,9'), ('[email protected]', '4,5,9'), ('[email protected]', '1,2,3'), ('[email protected]', '9,10'), ('[email protected]', '1,5'); Output ItemName NoOfOrders Product A 4 Product B 3 Product C 1 Product D 3 Product E 4 Product F 0 Product G 2 Product H 1 Product I 2 Product J 1 The Order List Stores the ItemsId as Comma separated value for every customer who places order.Like this i am having more than 40k Records in my dB table Now I am assigned with a task of creating report in which I should display Items and No of People ordered Items as Shown Below I Used Query as below in my PHP to bring the Orders One By One and storing in array. SELECT COUNT(PL.EmailId) FROM OrderList PL WHERE CSVProductIds LIKE '2' OR CSVProductIds LIKE '%,2,%' OR CSVProductIds LIKE '%,2' OR CSVProductIds LIKE '2,%'; 1.Is it possible to get the same out put by using Single Query 2.Does using a like in mysql query slows down the dB when the table has more no of records i.e 40k rows

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  • Does the order of the columns in a SELECT statement make a difference?

    - by Frank Computer
    This question was inspired by a previous question posted on SO, "Does the order of the WHERE clause make a differnece?". Would it improve a SELECT statement's performance if the the columns used in the WHERE section are placed at the begining of the SELECT statement? example: SELECT customer.id, transaction.id, transaction.efective_date, transaction.a, [...] FROM customer, transaction WHERE customer.id = transaction.id; I do know that limiting the list of columns to only the needed ones in a SELECT statement improves performance as opposed to using SELECT * because the current list is smaller.

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  • Query returning an ascending group number

    - by Dougman
    I have a query like below that has groups (COL1) and that group's values (COL2). select col1, col2 from (select 'A' col1, 1 col2 from dual union all select 'A' col1, 2 col2 from dual union all select 'B' col1, 1 col2 from dual union all select 'B' col1, 2 col2 from dual union all select 'C' col1, 1 col2 from dual union all select 'C' col1, 2 col2 from dual ) order by col1, col2; The output of this query looks like: COL1 COL2 ---- ---- A 1 A 2 B 1 B 2 C 1 C 2 What I need is a query that will return an ordered number increasing for each different group (COL1). It seems like there would be a simple way to accomplish this (maybe with analytics) but for some reason it is escaping me. GRPNUM COL1 COL2 ------ ---- ---- 1 A 1 1 A 2 2 B 1 2 B 2 3 C 1 3 C 2 I am running Oracle 10gR2.

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  • left join without duplicate values using MIN()

    - by Clipper87
    I have a table_1: id custno 1 1 2 2 3 3 and a table_2: id custno qty descr 1 1 10 a 2 1 7 b 3 2 4 c 4 3 7 d 5 1 5 e 6 1 5 f When I run this query to show the minimum order quantities from every customer: SELECT DISTINCT table_1.custno,table_2.qty,table_2.descr FROM table_1 LEFT OUTER JOIN table_2 ON table_1.custno = table_2.custno AND qty = (SELECT MIN(qty) FROM table_2 WHERE table_2.custno = table_1.custno ) Then I get this result: custno qty descr 1 5 e 1 5 f 2 4 c 3 7 d Customer 1 appears twice each time with the same minimum qty (& a different description) but I only want to see customer 1 appear once. I don't care if that is the record with 'e' as a description or 'f' as a description. How could I do this ? Thx!

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  • Is an index required for columns in ON clause?

    - by newbie
    Do I have to create an index on columns referenced in Joins? E.g. SELECT * FROM left_table INNER JOIN right_table ON left_table.foo = right_table.bar WHERE ... Should I create indexes on left_table(foo), right_table(bar), or both? I noticed different results when I used EXPLAIN (Postgresql) with and without indexes and switching around the order of the comparison (right_table.bar = left_table.foo) I know for sure that indexes are used for the left of the WHERE clause but I am wondering whether I need indexes for columns listed in ON clauses.

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  • How effecient 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?

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  • SQL query construction - separate data in a column into two columns

    - by Tommy
    I have a column that contains links. The problem is that the titles of the links are in the same column, so it looks like this: linktitle|-|linkurl I want link title and linkurl in separate columns. I've created a new column for the urls, so I'm looking for a way to extract them and update the linkurl column with them. Is there any clever way to construct a query that does this?

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  • PHP is truncating MSSQL Blob data (4096b), even after setting INI values. Am I missing one?

    - by Dutchie432
    I am writing a PHP script that goes through a table and extracts the varbinary(max) blob data from each record into an external file. The code is working perfectly, except when a file is over 4096b - the data is truncated at exactly 4096. I've modified the values for mssql.textlimit, mssql.textsize, and odbc.defaultlrl without any success. Am I missing something here? <?php ini_set("mssql.textlimit" , "2147483647"); ini_set("mssql.textsize" , "2147483647"); ini_set("odbc.defaultlrl", "0"); include_once('common.php'); $id=$_REQUEST['i']; $q = odbc_exec($connect, "Select id,filename,documentBin from Projectdocuments where id = $id"); if (odbc_fetch_row($q)){ echo "Trying $filename ... "; $fileName="projectPhotos/docs/".odbc_result($q,"filename"); if (file_exists($fileName)){ unlink($fileName); } if($fh = fopen($fileName, "wb")) { $binData=odbc_result($q,"documentBin"); fwrite($fh, $binData) ; fclose($fh); $size = filesize($fileName); echo ("$fileName<br />Done ($size)<br><br>"); }else { echo ("$fileName Failed<br>"); } } ?> OUTPUT Trying ... projectPhotos/docs/file1.pdf Done (4096) Trying ... projectPhotos/docs/file2.zip Done (4096) Trying ... projectPhotos/docsv3.pdf Done (4096) etc..

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  • How can I combine a LINQ query with an IQueryable<Guid>

    - by John
    I have a LINQ query that uses 1 table + a large number of views. I'd like to be able to write something like this: IQueryable<Guid> mostViewedWriters; switch (datePicker) { case DatePicker.Last12Hours: mostViewedWriters = from x in context.tempMostViewed12Hours select x.GuidId; break; case DatePicker.Last24Hours: mostViewedWriters = from x in context.tempMostViewed12Hours select x.GuidId; break; case DatePicker.Last36Hours: mostViewedWriters = from x in context.tempMostViewed12Hours select x.GuidId; break; } var query = from x1 in context.Articles join x2 in context.Authors on x1.AuthorId == x2.AuthorId join x3 in mostViewedWriters on x2.AuthorId == x3.Id select new { x2.AuthorName, x1.ArticleId, x1.ArticleTitle }; The above C# is pseudo-code written to protect the innocent (me). The gist of the question is this: I have a query that is related to the results of a view. That view, however, could be one of many different views. All the views return the same data type. I thought that I might be able to create an IQueryable that would contain the Ids that I need and use that query. Alas, that effort has stalled.

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  • Cakephp Autoconvert find() fields?

    - by Razor Storm
    In cake php I can grab a model's fields by using the find() method. What if I wish to apply a transformation function to the fields? Is there a way to directly accomplish this task? Suppose I have a model called RaceTime with the fields racerId and timeMillis RaceTime +------------+ | Field | +------------+ | id | | racerId | | timeMillis | +------------+ timeMillis is an int specifying how long the race took in milliseconds. Obviously saying a race took 15651 milliseconds isn't very useful to a human reader, and I would wish to convert this to a human readable format. Is there a way to accomplish this directly in find()? Or is the only option to loop through the results after find() finishes?

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  • Combine First, Middle Initial, Last name and Suffix in T-SQL (No extra spaces)

    - by Paul
    I'm trying not to reinvent the wheel here...I have these four fields [tbl_Contacts].[FirstName], [tbl_Contacts].[MiddleInitial], [tbl_Contacts].[LastName], [tbl_Contacts].[Suffix] And I want to create a FullName field in a view, but I can't have extra spaces if fields are blank...So I can't do FirstName + ' ' + MiddleInitial + ' ' + LastName + ' ' + Suffix...Because if there is no middle initial or suffix I'd have 2 extra spaces in the field. I think I need a Case statement, but I thought someone would have a handy method for this...Also, the middleinitial and suffix may be null.

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  • is Payment table needed when you have an invoice table like this?

    - by EBAGHAKI
    this is my invoice table: Invoice Table: invoice_id creation_date due_date payment_date status enum('not paid','paid','expired') user_id total_price I wonder if it's Useful to have a payment table in order to record user payments for invoices. payment table can be like this: payment_id payment_date invoice_id price_paid status enum('successful', 'not successful')

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  • How to repair "order by" after union of 2 selects from 1 tables

    - by 4e4el
    I have a dropDownList on my form, where i need to have union of values from 2 colums of table [ost]. Type of this columns is currency. I have russian version of access, default value of curency in "rur" and i need "uah". I need to change format and save "order by". I use this query: (SELECT distinct FORMAT([Sum1] ,'# ##0.00" uah.";-# ##0.00" uah."') FROM ost) Union (SELECT distinct FORMAT([Sum2],'# ##0.00" uah.";-# ##0.00" uah."') FROM ost) ORDER BY 1

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  • oracle query returns 4 duplicates of each row

    - by ajoe
    hello, I am Running a oracle query, it seems to work except that it returns 4 dupes of each result. here is the code: Select * from (Select a.*, rownum rnum From (SELECT NEW_USER.*, NEW_EHS_QUIZ_COMPLETE.datetime FROM NEW_USER, NEW_EHS_QUIZ_COMPLETE WHERE EXISTS(select * from NEW_EHS_QUIZ_COMPLETE where NEW_USER.id=NEW_EHS_QUIZ_COMPLETE.USER_ID) ORDER by last_name ASC ) a where rownum <= #pgtop# ) where rnum >= #pgbot# does anyone know why this isnt working properly? thanks in advance.

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  • "Remember" last three MySql queries; Cookie, passed variable or other method?

    - by Camran
    I have a classified website, with pretty sophisticated searching, and I am about to implement a function where the last three queries is displayed for the user, so that the user can go back easier through the queries. This because for each query the user has to provide a lot of input. I have four questions for you: I wonder, how can I save the actual query (SELECT * FROM etc etc)...? Do I need to add some form of encryption to be on the safe side? How will this affect performance? (I don't like the fact that cookies slow websites down) Anything else to think about? If you need more input, let me know... Btw, the website is PHP based. Thanks

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