Search Results

Search found 16051 results on 643 pages for 'schema design'.

Page 33/643 | < Previous Page | 29 30 31 32 33 34 35 36 37 38 39 40  | Next Page >

  • What schema documentation tools exist for PostgreSQL

    - by Brad Koch
    MySQL has MySQL Workbench for designing and documenting your schema, and generates CREATE and ALTER scripts based on your design. We're looking at migrating to PostgreSQL in the near future, and we do need a practical way of documenting and modifying the schema structure. What similar tools exist for Postgres (that are OS X/Linux compatible)? Alternatively, what equivalent conventions would be followed for designing and documenting the structure of your Postgres database?

    Read the article

  • Database schema for multiple category/product relationship

    - by sree01
    I want to design a database for an e-commerce application with category/subcategory management. Please suggest a database schema where we can create categories and subcategories and add products to those categories. Each product can have multiple categories and we can select products belong to multiple categories using a boolean database query Thanks

    Read the article

  • friendship database schema

    - by Daniel Hertz
    I'm creating a db schema that involves users that can be friends, and I was wondering what the best way to model the ability for these friends to have friendships. Should it be its own table that simply has two columns that each represent a user? Thanks!

    Read the article

  • Pattern for creating a database schema using JDBC

    - by Space_C0wb0y
    I have a Java-application that loads data from a legacy file format into an SQLite-Database using JDBC. If the database file specified does not exist, it is supposed to create a new one. Currently the schema for the database is hardcoded in the application. I would much rather have it in a separate file as an SQL-Script, but apparently there is now easy way to execute an SQL-Script though JDBC. Is there any other way or a pattern to achieve something like this?

    Read the article

  • XSD: how to use 'unique' & 'key'/'keyref' with element values?

    - by Koohoolinn
    I trying to use and / with element values but I just can't get it to work. If I do it with attrubute values it works like a charm. Test.xml <test:config xmlns:test="http://www.example.org/Test" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.example.org/Test Test.xsd "> <test:location id="id1" path="/path2"> <test:roles> <test:role>role1</test:role> <test:role>role2</test:role> <test:role>role2</test:role> <!-- DUPLICATE: FAIL VALIDATION --> </test:roles> <test:action name="action1"> <test:roles> <test:role>role1</test:role> <test:role>role1</test:role> <!-- DUPLICATE: FAIL VALIDATION --> <test:role>role3</test:role> <!-- NOT DEFINED: FAIL VALIDATION --> </test:roles> </test:action> </test:location> </test:config> I want ensure that roles are only defined once and that the roles defined under the action element are only those defined at the upper level. Test.xsd <xs:element name="config"> <xs:complexType> <xs:sequence> <xs:element ref="test:location" maxOccurs="unbounded" /> </xs:sequence> </xs:complexType> </xs:element> <xs:element name="location" type="test:LocationType"> <xs:key name="keyRole"> <xs:selector xpath="test:roles" /> <xs:field xpath="test:role" /> </xs:key> <xs:keyref name="keyrefRole" refer="test:keyRole"> <xs:selector xpath="test:action/test:roles" /> <xs:field xpath="test:role" /> </xs:keyref> </xs:element> <xs:complexType name="LocationType"> <xs:sequence> <xs:element ref="test:roles" minOccurs="0" /> <xs:element name="action" type="test:ActionType" minOccurs="0" maxOccurs="unbounded"/> </xs:sequence> <xs:attribute name="id" type="xs:string" use="required"/> <xs:attribute name="path" type="xs:string" use="required"/> </xs:complexType> <xs:element name="roles" type="test:RolesType"> <xs:unique name="uniqueRole"> <xs:selector xpath="." /> <xs:field xpath="test:role" /> </xs:unique> </xs:element> <xs:complexType name="RolesType"> <xs:sequence> <xs:element name="role" type="xs:string" maxOccurs="unbounded"/> </xs:sequence> </xs:complexType> <xs:complexType name="ActionType"> <xs:sequence> <xs:element ref="test:roles" /> </xs:sequence> <xs:attribute name="name" type="xs:string" use="required" /> </xs:complexType> The validation fails with these messages: Description Resource Path Location Type cvc-identity-constraint.3: Field "./test:role" of identity constraint "keyrefRole" matches more than one value within the scope of its selector; fields must match unique values. Test.xml /filebrowser-ejb/src/test/resources line 15 XML Problem cvc-identity-constraint.3: Field "./test:role" of identity constraint "keyrefRole" matches more than one value within the scope of its selector; fields must match unique values. Test.xml /filebrowser-ejb/src/test/resources line 16 XML Problem cvc-identity-constraint.3: Field "./test:role" of identity constraint "keyRole" matches more than one value within the scope of its selector; fields must match unique values. Test.xml /filebrowser-ejb/src/test/resources line 9 XML Problem cvc-identity-constraint.3: Field "./test:role" of identity constraint "keyRole" matches more than one value within the scope of its selector; fields must match unique values. Test.xml /filebrowser-ejb/src/test/resources line 10 XML Problem cvc-identity-constraint.3: Field "./test:role" of identity constraint "uniqueRole" matches more than one value within the scope of its selector; fields must match unique values. Test.xml /filebrowser-ejb/src/test/resources line 9 XML Problem cvc-identity-constraint.3: Field "./test:role" of identity constraint "uniqueRole" matches more than one value within the scope of its selector; fields must match unique values. Test.xml /filebrowser-ejb/src/test/resources line 10 XML Problem cvc-identity-constraint.3: Field "./test:role" of identity constraint "uniqueRole" matches more than one value within the scope of its selector; fields must match unique values. Test.xml /filebrowser-ejb/src/test/resources line 15 XML Problem cvc-identity-constraint.3: Field "./test:role" of identity constraint "uniqueRole" matches more than one value within the scope of its selector; fields must match unique values. Test.xml /filebrowser-ejb/src/test/resources line 16 XML Problem cvc-identity-constraint.4.1: Duplicate unique value [role1] declared for identity constraint "uniqueRole" of element "roles". Test.xml /filebrowser-ejb/src/test/resources line 9 XML Problem cvc-identity-constraint.4.1: Duplicate unique value [role1] declared for identity constraint "uniqueRole" of element "roles". Test.xml /filebrowser-ejb/src/test/resources line 15 XML Problem cvc-identity-constraint.4.2.2: Duplicate key value [role1] declared for identity constraint "keyRole" of element "location". Test.xml /filebrowser-ejb/src/test/resources line 9 XML Problem cvc-identity-constraint.4.3: Key 'keyrefRole' with value 'role3' not found for identity constraint of element 'location'. Test.xml /filebrowser-ejb/src/test/resources line 19 XML Problem If I comment out the lines that should fail, validation still fails now with these messages: Description Resource Path Location Type cvc-identity-constraint.3: Field "./test:role" of identity constraint "keyRole" matches more than one value within the scope of its selector; fields must match unique values. Test.xml /filebrowser-ejb/src/test/resources line 10 XML Problem cvc-identity-constraint.3: Field "./test:role" of identity constraint "uniqueRole" matches more than one value within the scope of its selector; fields must match unique values. Test.xml /filebrowser-ejb/src/test/resources line 10 XML Problem What am I doing wrong?

    Read the article

  • Two different definitions of database schema

    - by AspOnMyNet
    a) I found two definitions of schema: FIRST - A set of information that describes a table is known as a schema, and schemas are used to describe specific tables within a database, as well as entire databases (and the relationship between tables in them, if any). SECOND - A database schema is a way to logically group objects such as tables, views, stored procedures etc. Think of a schema as a container of objects. I assume the two descriptions describe entirely different concepts, which just happen to use the same name? b) A database schema is a way to logically group objects such as tables, views, stored procedures etc. Think of a schema as a container of objects. If I understand the above definition correctly, then database schema is similar to a namespace, only difference being that we can assign access permissions to database schema, while same can’t be done with namespaces? thanx

    Read the article

  • XSD problem: The value of attribute on element is not valid with respect to its type

    - by Tom Brito
    (First of all, I'm trying to learn how to handle xsd files, I know very little) I got this xsd, and just copy to Eclipse IDE, and it says there an error on line 26: <xs:element name="Issuer" type="dkx:IssuerType" /> saying: cvc-attribute.3: The value 'dkx:IssuerType' of attribute 'type' on element 'xs:element' is not valid with respect to its type, 'QName'. Any idea what is this? (as this is an example file, I'm assuming it is an independent file, hope it is)

    Read the article

  • NHibernate SchemaUpdate adding existing foreign keys again?

    - by afsharm
    I'm using SchemaUpdate to synchronize my hbms with existing database. Database has recently created based on hbms and is completely up-to-date. But SchemaUpdate generates all foreign key constraints again. For example suppose you have Student and Teacher. Student has association to Teacher with name ArtTeacher. ArtTeacher is a foreign key from Student to Teacher. Suppose database is up-to-date and currently holde Student, Teacher and their foreign key relation. So HBM and Database are equivalent. Know SchemaUpdate must not do anything but when I see its generated scripts, it re-produce that foreign key again. Why this happens? Is there any way to avoid it?

    Read the article

  • Quick and Good: ( Requirement -> Validation -> Design ) for self use?

    - by Yugal Jindle
    How to casually do the required Software Engineering and designing? I am an inexperienced developer and face the following problem: My company is a start up and has no fix Software engineering systems. I am assigned tasks with not very clear and conflicting requirements. I don't have to follow any designs or verify requirements officially. Problem: I code all day and finally get stuck where requirement conflicts and I have to start over again. I can-not spend a lot of time doing proper SRS or SDD. How should I: List out Requirements for myself. (Not an official document) How to verify and validate the requirements? How to visualize them? How to design them with minimum effort? (As its going to be with me only) I don't want to waste my time coding something that's gonna collapse according to requirement conflict or something! I don't want to compromise with quality but don't want to re-write everything on some change that I didn't expected. I imagine making a diagram for my thought process that will show me conflict in the diagram itself, then finally correcting the diagram - I decide my design and structure my code in terms of interfaces or something. And then finally start implementing my design. I am able to sense the lack of systematic approach, but don't know how to proceed! Update: Please suggest me some tools that can ask me the questions and help me aggregate important details. How can I have diagram that I talked about for requirement verification?

    Read the article

  • Database Table Schema and Aggregate Roots

    - by bretddog
    Hi, Applicaiton is single user, 1-tier(1 pc), database SqlCE. DataService layer will be (I think) : Repository returning domain objects and quering database with LinqToSql (dbml). There are obviously a lot more columns, this is simplified view. http://img573.imageshack.us/img573/3612/ss20110115171817w.png This is my first attempt of creating a 2 tables database. I think the table schema makes sense, but I need some reassurance or critics. Because the table relations looks quite scary to be honest. I'm hoping you could; Look at the table schema and respond if there are clear signs of troubles or errors that you spot right away.. And if you have time, Look at Program Summary/Questions, and see if the table layout makes makes sense to those points. Please be brutal, I will try to defend :) Program summary: a) A set of categories, each having a set of strategies (1:m) b) Each day a number of items will be produced. And each strategy MAY reference it. (So there can be 50 items, and a strategy may reference 23 of them) c) An item can be referenced by more than one strategy. So I think it's an m:m relation. d) Status values will be logged at fixed time-fractions through the day, for: - .... each Strategy.....each StrategyItem....each item e) An action on an item may be executed by a strategy that reference it. - This is logged as ItemAction (Could have called it StrategyItemAction) User Requsts b) - e) described the main activity mode of the program. To work with only today's DayLog , for each category. 2nd priority activity is retrieval of history, which typically will be From all categories, from day x to day y; Get all StrategyDailyLog. Questions First, does the overall layout look sound? I'm worried to see that there are so many relationships in all directions, connecting everything. Is this normal, or does it look like trouble? StrategyItem is made to represent an m:m relationship. Is it correct as I noted 1:m / 1:1 (marked red) ? StrategyItemTimeLog and ItemTimeLog; Logs values that both need to be retrieved together, when retreiving a StrategyItem. Reason I separated is that the first one is strategy-specific, and several strategies can reference same item. So I thought not to duplicate those values that are not dependent no strategy, but only on the item. Hence I also dragged out the LogTime, as it seems to be the only parameter to unite the logs. But this all looks quite disturbing with those 3 tables. Does it make sense at all? Or you have suggestion? Pink circles shows my vague attempt of Aggregate Root Paths. I've been thinking in terms of "what entity is responsible for delete". Though I'm unsure about the actual root. I think it's Category. Does it make sense related to User Requests described above?

    Read the article

  • Windows Phone 7 Design using Expression Blend - Resources

    - by Nikita Polyakov
    I’ve been doing a series of talks across Florida regarding Windows Phone 7 Design using Microsoft Expression Blend 4. I discuss the WP7 phone and application experience; show how to use Expression Blend toolset to effectively design such apps. Next presentation is on 5/4/2010 at 6:30PM EST will be a webcast format over LiveMeeting at Ft. Lauderdale Online group. Registration and the LiveMeeting link are both here: http://www.fladotnet.com/Reg.aspx?EventID=459 [I will post a link if it’s recorded]   Here are the resources from my presentations: The Biggest source is the Windows Phone UI and Design Language video from MIX10 Windows Phone 7 Design Guide as it’s found on the WP7 Dev Home Page Study The Silverlight Mobile Tutorials on official Silverlight website I will be blogging a separate entry for a new demo app that will showcase the elements I presented. I suggest you actually watch all of the MIX videos about SL and Design as great primer to get you thinking the WP7 way.   A lot happening with WP7Dev and it’s just the beginning! So watch these Twitter accounts and blogs: @Ckindel - Charlie Kindel - WP7 Dev Head http://blogs.msdn.com/ckindel @WP7Dev - Official Dev Twitter @WP7 - Official WP7 Twitter Peter Torr - http://blogs.msdn.com/ptorr Mike Harsh - http://blogs.msdn.com/mharsh Shawn Oster - http://www.shawnoster.com   Other worthwhile mention my local friends speaking and blogging about Windows Phone 7: Bill Reiss is doing great presentations on Building games with XNA for Windows Phone 7. Be on the lookout for those around Florida. Bill is a Silverlight MVP and has a legacy of XNA and Silverlight games, see his site. Kevin Wolf aka ByteMaster he is a Device Application Developer MVP with tremendous experience building mobile applications. He has developed WinMo-GF a multi-platform gaming framework. Get these tools and get creating! You will need the following components installed in this order: Expression Blend 4 Beta Windows Phone Developer Tools Microsoft Expression Blend Add-in Preview for Windows Phone Microsoft Expression Blend SDK Preview for Windows Phone Want more training? Don’t forget that Channel 9 has complete walkthroughs of their WP7 Training Kit posted online. PS: To continue with all this design talk check out Microsoft .toolbox “Learn to create Silverlight applications using Expression Studio and to apply fundamental design principles.” A great website with a lot of design tutorials set up as a wonderful full course on design all for free, including a great forum community and neat little avatars you can build yourself.

    Read the article

  • Design a T-shirt for .NET Reflector Pro

    - by Laila
    Win a .NET Reflector Pro license, a box of Red Gate goodies, and a t-shirt printed with your design! Red Gate likes t-shirts. Each of our teams has one. In fact, each individual person has one, numbered according to when they joined the company: Red Gate's 1st, 2nd, and so on right up to Red Gate's 170th, with the slogan "More than just a number". Those t-shirts are important, chiefly because they remind the people wearing them that they are important. But that isn't enough. What really makes us great are the people who choose to use our tools. So we'd like to extend our tradition of t-shirts to include you and put the design of our next shirt entirely in your hands. We'd like you to come up with a witty slogan or create an inventive or simply beautiful t-shirt design for .NET Reflector Pro, our add-in for Visual Studio, which allows you to step into decompiled assemblies whilst debugging in Visual Studio. When you're done, post your masterpiece to Twitter with the hash tag #reflectortees, and @redgate will take a look! We'll pick the best design, and the winner will get a licensed copy of .NET Reflector Pro and a box of Red Gate goodies - not to mention a copy of their t-shirt. The winning design will go into production and be worn and given out at tradeshows, conferences, and user group events across the world, proudly bearing the name of their designer. We'll also pick three runners-up who will receive licenses for .NET Reflector Pro. Red Gate goodie box Interested? If you're up for the challenge, then we've got some resources to get you started. Inside the .zip file you'll find high-quality versions of the following: T-shirt templates: don't forget to design the front and the back! Different versions of the .NET Reflector Pro logo and Red Gate logo. Colour sheets to give you an easy reference to the Red Gate colours, including hex and RGB values. You can create and send us as many designs as you like, and each of them will be considered for the prize. To submit your designs, simply tweet including the competition hash tag, #reflectortees, and a link to somewhere we can see your design: either an image hosting site such as Twitpic, Flickr or Picasa, or a personal blog. You will need to create a Twitter account (which is free), if you don't already have one. You only have three limits: The background colour of the t-shirt should be one of our brand colours (red, light/dark grey or black), though you're welcome to use other colours in the rest of the design. You need to make use of either the .NET Reflector Pro logo OR the Red Gate logo (please keep them as they are) If you include any text or slogan, stick with just one or two colors for it. Apart from that, go wild. Go and do whatever it is you do when you get creative: whether you walk barefoot on the grass with a pencil and paper, sit cross-legged on a pile of cushions with a laptop, or simply close your eyes and float through a mist of ideas, now is your chance. Make sure you enjoy it. We're looking forward to seeing your creations. Terms and conditions 1. The closing date for entries is June 11th, 2010 (4 p.m. UK time). Red Gate Software Ltd reserves the right to extend the competition deadline at its discretion. If there is a revision, the revised date will be published on this blog and the date for announcing the results will be postponed accordingly. 2. The winning designer will be notified on June 14th, 2010 through Twitter. The winner must claim his/her prize by sending us a high-resolution image of their design via email (i.e. Illustrator EPS files or appropriate format, ideally at 300dpi). If the winner does not come forward within 3 days of the announcement, they will forfeit their prize and another winner will be selected from the runners-up. The names of the winner and runners-up will be posted on this blog by June 18th.  3. Entry is completed on the designer posting a link to their entry in a tweet with the correct hash tag, #reflectortees. 4. Red Gate Software needs to hold the rights to using the winning design in order to put the t-shirt into production. We will make sure that this is fine with the winner before we do so, but if you do not want us holding the rights to your design, please do not submit your designs. We reserve the right to slightly alter or adjust any artwork we decide to use (mainly to make it easier to print), but we will make sure we contact the winner for approval first. The winner will also need to allow us the use of his/her name for purposes of promoting your design. 5. Entries must be entirely your own original work and must not breach any copyright or third party rights. Red Gate Software Ltd will not be made partially or fully liable for any non-original work submitted by you. 6. This competition is free: you do not need to buy anything or be an existing customer to enter. 7. This competition is not open to employees of Red Gate Software Ltd, their families, or any other company directly connected with the administration of this promotion.

    Read the article

  • Nested Data XML design

    - by esryl
    Looking to nest (to unlimited levels) elements in XML. Like so: <items> <item> <name>Item One</name> <item> <name>Item Two</name> </item> <item> <name>Item Three</name> <item> <name>Item Four</name> </item> <!-- etc... --> </item> </item> </items> However. While browsing for a solution I noticed in the comments of: http://stackoverflow.com/questions/988139/weird-nesting-in-xml while the above is well formed it would not validate against any sinsible DTD. Two things, what is a better way of nesting similar elements, and secondly what would be the design of the DTD. UPDATE: Would prefer to validate against an XML Schema rather than DTD.

    Read the article

  • Is MVC a Design Pattern or Architectural pattern

    - by JCasso
    According to Sun and Msdn it is a design pattern. According to Wikipedia it is an architectural pattern In comparison to design patterns, architectural patterns are larger in scale. (Wikipedia - Architectural pattern) Or it is an architectural pattern that also has a design pattern ? Which one is true ?

    Read the article

  • Are ORM's counterproductive to OO design?

    - by Jeremiah
    In OOD, design of an object is said to be characterized by its identity and behavior. Having used OR/M's in the past, the primary purpose, in my opinion, revolves around the ability to store/retrieve data. That is to say, OR/M objects are not design by behavior, but rather data (i.e. database tables). Case and point: Many OR/M tools come with a point-to-a-database-table-and-click-object-generator. If objects are no longer characterized by behavior this will, in my opinion, muddy the identity and responsibility of the objects. Subsequently, if objects are not defined by a responsibility this could lend a hand to having tightly coupled classes and overall poor design. Furthermore, I would think that in an application setting, you would be heading towards scalability issues. So, my question is, do you think that ORM's are counterproductive to OO design? Perhaps the underlying question would be whether or not they are counterproductive to application development.

    Read the article

  • database design suggestion needed

    - by JMSA
    I need to design a table for daily sales of pharmaceutical products. There are hundreds of types of products available {Name, code}. Thousands of sales-persons are employed to sell those products{name, code}. They collect products from different depots{name, code}. They work in different Areas - Zones - Markets - Outlets, etc. {All have names and codes} Each product has various types of prices {Production Price, Trade Price, Business Price, Discount Price, etc.}. And, sales-persons are free to choose from those combination to estimate the sales price. The problem is, daily sales requires huge amount of data-entry. Within couple of years there may be gigabytes of data (if not terabytes). If I need to show daily, weekly, monthly, quarterly and yearly sales reports there will be various types of sql queries I shall need. This is my initial design: Product {ID, Code, Name, IsActive} ProductXYZPriceHistory {ID, ProductID, Date, EffectDate, Price, IsCurrent} SalesPerson {ID, Code, Name, JoinDate, and so on..., IsActive} SalesPersonSalesAraeaHistory {ID, SalesPersonID, SalesAreaID, IsCurrent} Depot {ID, Code, Name, IsActive} Outlet {ID, Code, Name, AreaID, IsActive} AreaHierarchy {ID, Code, Name, PrentID, AreaLevel, IsActive} DailySales {ID, ProductID, SalesPersonID, OutletID, Date, PriceID, SalesPrice, Discount, etc...} Now, apart from indexing, how can I normalize my DailySales table to have a fine grained design that I shall not need to change for years to come? Please show me a sample design of only the DailySales data-entry table (from which all types of reports would be queried) on the basis of above information. I don't need a detailed design advice. I just need an advice regarding only the DailySales table. Is there any way to break this particular table to achieve granularity?

    Read the article

  • Design Help! How can design Extended properties for Entity with simple and complex data in extended

    - by mmtemporary
    I have design question. I have entity such as "Person". Person has properties such as: FirstName, LastName, Gender, BirthDate, .... End user when create a person in application may be need to define another property that is not defined in database table schema (or class person). for example: end user nead to define "property1" that its a string property. or nead define "proerty2" that its a image, or need define "property3" that its complex type. please separate your design solution in tow level: 1-database table design 2-class design thank u.

    Read the article

  • MongoDB RSS Feed Entries, Embed the Entries in the Feed Object?

    - by Patrick Klingemann
    I am saving a reference to an RSS Feed in MongoDB, each Feed has an ever growing list of Entries. As I'm designing my schema, I'm concerned about this statement from the MongoDB Schema Design - Embed vs. Reference Documentation: If the amount of data to embed is huge (many megabytes), you may read the limit on size of a single object. This will surely happen if I understand the statement correctly. So the question is, I am correct to assume that I should not embed the Feed Entries within a Feed because I'll eventually reach the limit on size of a single object?

    Read the article

  • how to design this relation in a DB schema

    - by raticulin
    I have a table Car in my db, one of the columns is purchaseDate. I want to be able to tag every car with a number of Policies (limited to 10 policies). Each policy has a time to life (ttl, a duration of time, like '5 years', '10 months' etc), that is, for how long since the car's purchaseDate the policy can be applied. I need to perform the following actions: when inserting a Car, it will be set with a number of Policies (at least one is set) sometimes a Car will be updated to add/remove a Policy searches must be done taking into account date/policies, for example: 'select all cars that are not covered by any policy as of today' My current design is (pol0..pol9 are the policies): CREATE TABLE Car ( id int NOT NULL IDENTITY(1,1), purchaseDate datetime NOT NULL, //more stuff... pol0 smallint default NULL, pol1 smallint default NULL, pol2 smallint default NULL, pol3 smallint default NULL, pol4 smallint default NULL, pol5 smallint default NULL, pol6 smallint default NULL, pol7 smallint default NULL, pol8 smallint default NULL, pol9 smallint default NULL, PRIMARY KEY (id) ) CREATE TABLE Policy ( id smallint NOT NULL, name varchar(50) collate Latin1_General_BIN NOT NULL, ttl varchar(100) collate Latin1_General_BIN NOT NULL, PRIMARY KEY (id) ) The problem I am facing is that the sql to perform the query above is a nightmare to write. As I don't know in which column each policy can be, so I have to check all columns for every policy etc etc. So I am wondering wether it is worth changing this. My questions are: The smallint as Policy id was chosen instead of an 'int IDENTITY' in order to save some space as there are going to be millions of Car records. It just adds complexity when creating a Policy as we must handle the id etc. Was it worth doing this? I am thinking that maybe there is a much better design? Obviously we could move the policy/car relation to its own table CarPolicy, benefits would be: no limit on 10 policies per car adding/removing etc much easier when only the default policy is applied (when no others are applied one called Default policy is applied), we could signal that by not having any entry in CarPolicy, now this is just done inserting the Default policy id in one of the columns. The cons are that we would need to change the DB, ORM classes etc. What would you recommend? Maybe there is another smart way to implement this that we are not aware without using the CarPolicy table?

    Read the article

  • Design pattern for adding / removing elements

    - by de3
    Wikipedia's definition for Iterator pattern design: the Iterator pattern is a design pattern in which iterators are used to access the elements of an aggregate object sequentially without exposing its underlying implementation. Iterator interface in java provides the following methods hasNext() next() remove() Is there a pattern design, or a java interface for inserting / deleting elements, and getting length of the aggregate object, in addition to iterating them? I know remove() is an optional method that can be used once per call to next(), but I am implementing a circular FIFO array and need a method delete() independent of iterator's next().

    Read the article

  • Design Pattern for "Context Sensitive" Right Click Menu

    - by MadSeb
    Hi, What is a design pattern I can use for generating "context-sensitive" right click menus ? I have in mind a "Windows Explorer"-like application where a user can right click on a folder and get a list of menu items but right click on a drive and get a totally different list. What design pattern should I use ? Would the factory design pattern be appropiate for handling such a menu ? Regards, Seb

    Read the article

< Previous Page | 29 30 31 32 33 34 35 36 37 38 39 40  | Next Page >