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  • Product Catalog Schema design

    - by FlySwat
    I'm building a proof of concept schema for a product catalog to possibly replace a very aging and crufty one we use. In our business, we sell both physical materials and services (one time and reoccurring charges). The current catalog schema has each distinct category broken out into individual tables, while this is nicely normalized and performs well, it is fairly difficult to extend. Adding a new attribute to a particular product involves changing the table schema and backpopulating old data. An idea I've been toying with has been something along the line of a base set of entity tables in 3rd normal form, these will contain the facts that are common among ALL products. Then, I'd like to build an Attribute-Entity-Value schema that allows each entity type to be extended in a flexible way using just data and no schema changes. Finally, I'd like to denormalize this data model into materialized views for each individual entity type. This views are what the application would access. We also have many tables that contain business rules and compatibility rules. These would join against the base entity tables instead of the views. My big concerns here are: Performance - Attribute-Entity-Value schemas are flexible, but typically perform poorly, should I be concerned? More Performance - Denormalizing using materialized views may have some risks, I'm not positive on this yet. Complexity - While this schema is flexible and maintainable using just data, I worry that the complexity of the design might make future schema changes difficult. For those who have designed product catalogs for large scale enterprises, am I going down the totally wrong path? Is there any good best practice schema design reading available for product catalogs?

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  • Two n x m relationships with the same table in mysql

    - by Christian
    I want to create a database in which there's an n x m relationship between the table drug and the table article and an n x m relationship between the table target and the table article. I get the error: Cannot delete or update a parent row: a foreign key constraint fails What do I have to change in my code? DROP TABLE IF EXISTS `textmine`.`article`; CREATE TABLE `textmine`.`article` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT 'Pubmed ID', `abstract` blob NOT NULL, `authors` blob NOT NULL, `journal` varchar(256) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; DROP TABLE IF EXISTS `textmine`.`drugs`; CREATE TABLE `textmine`.`drugs` ( `id` int(10) unsigned NOT NULL COMMENT 'This ID is taken from the biosemantics dictionary', `primaryName` varchar(256) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; DROP TABLE IF EXISTS `textmine`.`targets`; CREATE TABLE `textmine`.`targets` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `primaryName` varchar(256) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; DROP TABLE IF EXISTS `textmine`.`containstarget`; CREATE TABLE `textmine`.`containstarget` ( `targetid` int(10) unsigned NOT NULL, `articleid` int(10) unsigned NOT NULL, KEY `target` (`targetid`), KEY `article` (`articleid`), CONSTRAINT `article` FOREIGN KEY (`articleid`) REFERENCES `article` (`id`), CONSTRAINT `target` FOREIGN KEY (`targetid`) REFERENCES `targets` (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; DROP TABLE IF EXISTS `textmine`.`contiansdrug`; CREATE TABLE `textmine`.`contiansdrug` ( `drugid` int(10) unsigned NOT NULL, `articleid` int(10) unsigned NOT NULL, KEY `drug` (`drugid`), KEY `article` (`articleid`), CONSTRAINT `article` FOREIGN KEY (`articleid`) REFERENCES `article` (`id`), CONSTRAINT `drug` FOREIGN KEY (`drugid`) REFERENCES `drugs` (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8;

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  • Multiple rows with a single INSERT in SQLServer 2008

    - by Todd
    I am testing the speed of inserting multiple rows with a single INSERT statement. For example: INSERT INTO [MyTable] VALUES (5, 'dog'), (6, 'cat'), (3, 'fish) This is very fast until I pass 50 rows on a single statement, then the speed drops significantly. Inserting 10000 rows with batches of 50 take 0.9 seconds. Inserting 10000 rows with batches of 51 take 5.7 seconds. My question has two parts: Why is there such a hard performance drop at 50? Can I rely on this behavior and code my application to never send batches larger than 50? My tests were done in c++ and ADO.

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  • Optimize this MySQL query?

    - by HipHop-opatamus
    The following query takes FOREVER to execute (30+ hrs on a Macbook w/4gig ram) - I'm looking for ways to make it run more efficiently. Any thoughts are appreciated! CREATE TABLE fc AS SELECT threadid, title, body, date, userlogin FROM f WHERE pid NOT IN (SELECT pid FROM ft) ORDER BY date; (table "f" is ~1 Gig / 1,843,000 row, table "ft" is 168mb, 216,000 rows) )

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  • What is C# equivalent of PHP's mysql_fetch_array function?

    - by Mike Biff
    I am learning C#/ASP.NET and I am wondering what the C# equivalent of the following PHP code is? I know the userid, and I want to fetch the rows from this table into the array of the variable "row", so I then can use it as "row['name']" and "row['email']. $result = mysql_query("SELECT email, name FROM mytable WHERE id=7"); while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) { printf("Email: %s Name: %s", $row["email"], $row["name"]); } Thanks.

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  • Teradata group by time interval

    - by matt123
    Can anyonen help with Teradata? I want to create a query that is a standard select count(*) from Table where Column = Something but has a group by time period done by 5 minute time intervals the time column is in 'Time' format any idea?

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  • Database with users design

    - by 1110
    I am in database design development phase. Application will work with large number of users (LARGE :)) I designed 80% of database but I have one Users table which is connected to everything else: Users {UserId, FirstName, LastName, Username, Password, PasswordQuestion, PasswordAnswer, Gender, RoleId, LastLoginDate etc etc} I saw asp.net membership database structure where Users and Membership are two tables. My questions are: Should I use one users table with all users data in it or more tables? If answer is 'more tables', what tables to use? Any advice on how to structure relation between those tables? This is sample relation that I have, and trying to improve. I don't understand why user and userChild are separated tables?

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  • Explanation of converting exporting an XML document as a relational database using XSLT

    - by Yaaqov
    I would like to better understand the basic steps needed to a take an XML document like this Breakfast Menu... <?xml version="1.0" encoding="ISO-8859-1"?> <breakfast_menu> <food> <name>Belgian Waffles</name> <price>$5.95</price> <description>two of our famous Belgian Waffles with plenty of real maple syrup</description> <calories>650</calories> </food> <food> <name>Strawberry Belgian Waffles</name> <price>$7.95</price> <description>light Belgian waffles covered with strawberries and whipped cream</description> <calories>900</calories> </food> <food> <name>Berry-Berry Belgian Waffles</name> <price>$8.95</price> <description>light Belgian waffles covered with an assortment of fresh berries and whipped cream</description> <calories>900</calories> </food> <food> <name>French Toast</name> <price>$4.50</price> <description>thick slices made from our homemade sourdough bread</description> <calories>600</calories> </food> <food> <name>Homestyle Breakfast</name> <price>$6.95</price> <description>two eggs, bacon or sausage, toast, and our ever-popular hash browns</description> <calories>950</calories> </food> </breakfast_menu> And "export" it to say, an Access or MySQL database using XSLT, creating two joined tables: Table: breakfast_menu Field: menu_item_id Field: food_id Table: food Field: food_id Field: name Field: price Field: description Field: calories If there are online tutorials on this that you know of, I'd be interesting in learning more, as well. Thanks.

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  • Inserting "null" (literally) in to a stored procedure parameter.

    - by Nazadus
    I'm trying to insert the word "Null" (literally) in to a parameter for a stored procedure. For some reason SqlServer seems to think I mean NULL and not "Null". If I do a check for IF @LastName IS NULL // Test: Do stuff Then it bypasses that because the parameter isn't null. But when I do: INSERT INTO Person (<params>) VALUES (<stuff here>, @LastName, <more stuff here>); // LastName is 'Null' It bombs out saying that LastName doesn't accept nulls. I would seriously hate to have this last name, but someone does... and it's bombing the application. We're using SubSonic 2.0 (yeah, it's fairly old but upgrading is painful) as our DAL and stepping through it, I see it does create the parameters properly (for what I can tell). I've tried creating a temp table to see if I could replicate it manually but it seems to work just fine. Here is the example I create: DECLARE @myval VARCHAR(50) SET @myval = 'Null' CREATE TABLE #mytable( name VARCHAR(50)) INSERT INTO #mytable VALUES (@myval) SELECT * FROM #mytable DROP table #mytable Any thoughts on how I can fix this?

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  • tsql getdate conversion

    - by Manjot
    Hi, I know that when i do the following, it converts getdate to int select cast (getdate() as int) Getdate output on my server is "2010-06-11 14:42:20.100" and the int to which the above command is converting to is 40339. What is this integer? Did this int consider minutes and seconds? i am confused. Please help. Regards Manjot

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  • Best Practices - Stored Procedure Logging

    - by hgulyan
    If you have a long running SP, do you log somehow it's actions or just wait for this message? "Command(s) completed successfully." I assume, that there can be plenty solutions on this subject, but is there any best practice - a simple solution that is frequently used? EDIT I've found an interesting link on this subject http://weblogs.sqlteam.com/brettk/archive/2006/09/21/12391.aspx Article describes using a log table, but there's an issue The logging procedure must be executed outside of any transaction I can't call that insert outside, because of cursor that I use and insert a line to that table on every row. Any ideas?

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  • Making a DateTime field in a database automatic?

    - by Mike
    I'm putting together a simple test database to learn MVC with. I want to add a DateTime field to show when the record was CREATED. ID = int Name = Char DateCreated = (dateTime, DateTime2..?) I have a feeling that this type of DateTime capture can be done automatically - but that's all I have, a feeling. Can it be done? And if so how? While we're on the subject: if I wanted to include another field that captured the DateTime of when the record was LAST UPDATED how would I do that. I'm hoping to not do this manually. Many thanks Mike

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  • Entity Framework Many-To-Many with additional field on Joining Table

    - by Cory G
    I have an entity context that includes three tables (see diagram here). The first is a table that contain products, the second contains recipes. The joining table has fields for IDs in both the products and recipes table as well as a 'bit' field called 'featured'. I've searched and found no example on how to insert only how to select against this type of scenario.Does anyone have any suggestions on how this can be done? Thanks in advance for any help. Cory

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  • How to ignore blank elements in linq query

    - by Maestro1024
    How to ignore blank elements in linq query I have a linq query var usersInDatabase = from user in licenseUserTable where user.FirstName == first_name && user.LastName == last_name select user; But if I get here and first_name or last_name is blank then I want to still evaluate the other data item.

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  • Storing a SHA512 Password Hash in Database

    - by Chris
    In my ASP.NET web app I'm hashing my user passwords with SHA512. Despite much SO'ing and Googling I'm unclear how I should be storing them in the database (SQL2005) - the code below shows the basics of how I'm creating the hash as a string and I'm currently inserting it into the database into a Char(88) column as that seems to be the length created consistently Is holding it as a String the best way to do it, if so will it always be 88 chars on a SHA512 (as I have seen some bizarre stuff on Google)? Dim byteInput As Byte() = Encoding.UTF8.GetBytes(sSalt & sInput) Dim hash As HashAlgorithm = New SHA512Managed() Dim sInsertToDatabase As String = Convert.ToBase64String(hash.ComputeHash(byteInput))

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  • Isn't INT more efficient than UNIQUEIDENTIFIER?

    - by ck
    I have a parent table and child table where the columns that join them together are the UNIQUEIDENTIFIER type. The child table has a clustered index on the column that joins it to the parent table (its PK, which is also clustered). I have created a copy of both of these tables but changed the relationship columns to be INTs instead, have rebuilt the indexes so that they are essentially the same structure and can be queried in the same way. When I query for a known 20 records from the parent table, pulling in all the related records from the child tables, I get identical query costs across both, i.e. 50/50 cost for the batches. If this is true, then my giant project to change all of the tables like this appears to be pointless, other than speeding up inserts. Can anyone provide any light on the situation?

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  • Optimizing Oracle query

    - by Omnipresent
    SELECT MAX(verification_id) FROM VERIFICATION_TABLE WHERE head = 687422 AND mbr = 23102 AND RTRIM(LTRIM(lname)) = '.iq bzw' AND TO_CHAR(dob,'MM/DD/YYYY')= '08/10/2004' AND system_code = 'M'; This query is taking 153 seconds to run. there are millions of rows in VERIFICATION_TABLE. I think query is taking long because of the functions in where clause. However, I need to do ltrim rtrim on the columns and also date has to be matched in MM/DD/YYYY format. How can I optimize this query?

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  • Trigger Code on a table in my ERP Database

    - by David Stein
    My ERP Vendor has the following trigger on a table: SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TRIGGER [dbo].[SOItem_DeleteCheck] ON [dbo].[soitem] FOR DELETE AS BEGIN DECLARE @RecCnt int, @LogInfo varchar(256) SET @RecCnt = (SELECT COUNT(*) FROM deleted) IF @RecCnt > 150 BEGIN RAISERROR (54010, 18, 1, 'SOItem') WITH LOG ROLLBACK TRANSACTION END SET @LogInfo = 'Deleting ' + LTRIM(STR(@RecCnt)) + ' Rows From SOItem' EXEC LogDeletes @LogInfo END GO This seems very inefficient to me. Doesn't select count(*) take longer than Count(specific field)?

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  • Unique Key in MySql

    - by Vinodtiru
    I have a table with four Columns. Col1, Col2, Col3, and Col4. Col1, Col2, Col3 is string and Col4 is a integer primary key with Auto Increment. Now my requirement is to have unique combination of Col2 and Col3. I mean to say like. Insert into table(Col1,Col2,Col3) Values('val1','val2','val3'); Insert into table(Col1,Col2,Col3) Values('val4','val2','val3'); the second statement has to throw error as the same combination of 'val2','val3' is present in the table. But i cant make it as a primary key as i need a auto increment column and for that matter the col4 has to be primary. Please let me know a approach by which i can have both in my table. Any kind of help is appreciated. Thanks.

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  • How determine database server IP via UDP in Java

    - by Wolfgang Lenhard
    Hi, I am writing clients in Java that store the data on a database server. So far, the IP and Port of the server has to be specified in the client's settings manually. I have heard, that it is possible to automatically determine the IP of database servers via broadcast / multicast / UDP (I am not familiar with these concepts). Question: Is there a way to retrieve the IP adresses of all available database-servers in the local network? I am working with the h2 database system so far. Bye, Wolfgang

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  • Which Database to choose?

    - by Sundar
    I have the following criteria Database should be protected with a username and password. It should not be possible to copy the database file and use it else were like MS Access. There will be no central database server. Each machine will run their own database server locally and user will initiate synchronization. Concept is inspired from distributed version control system like Git. So it should have good replication support. Strong consistency is not needed. Users will synchronize each other database when they need. In case of conflicts it should be possible to find the conflict and present it (from application) to the user for fixing it. Revisions of data if available it will be good. e.g. Entire history of change to a invoice. I explored document oriented database and inclined towards the same. But I dont know what to choose. Database is small it will not reach even 1GB in the next few years (say 3 years). Please feel free to suggest any database which you think might be suitable. Any pointers is highly appreciated. Thanks in advance.

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  • How do You Get a Specific Value From a System.Data.DataTable Object?

    - by Giffyguy
    I'm a low-level algorithm programmer, and databases are not really my thing - so this'll be a n00b question if ever there was one. I'm running a simple SELECT query through our development team's DAO. The DAO returns a System.Data.DataTable object containing the results of the query. This is all working fine so far. The problem I have run into now: I need to pull a value out of one of the fields of the first row in the resulting DataTable - and I have no idea where to even start. Microsoft is so confusing about this! Arrrg! Any advice would be appreciated. I'm not providing any code samples, because I believe that context is unnecessary here. I'm assuming that all DataTable objects work the same way, no matter how you run your queries - and therefore any additional information would just make this more confusing for everyone.

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