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  • Specify XML schema data type of decimal or blank

    - by Jeremy Stein
    Is there a way in an XML schema to specify that an element may contain either an empty string or a decimal? If I specify the type as xs:decimal like this: <xs:element name="Sample" type="xs:decimal" /> then a blank value would not pass validation: <Sample/> (I realize that the best way to indicate no value would be to not include the element, but I was wondering if there was a way to allow blank or decimal.)

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  • Automatic database schema generation and migration with Perl

    - by pistacchio
    In Ror or Django or web2py you can "describe" a database (as a set of classes that remaps to tables) and the framework (having being provided with a connection string to the desired database) generates the tables, fields, relations and in the case of RoR and web2py it also keeps it up-to-date (eg, removing a class drops the table, adding a property to the class triggers an "alter table add" etc). Is there any Perl module that does the same? Eg, it takes the YAML/XML/JSON description of a database as input and modifies/generates the database schema accordingly?

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  • Any good SQL Anywhere database schema comparison tools?

    - by Lurker Indeed
    Are there any good database schema comparison tools out there that support Sybase SQL Anywhere version 10? I've seen a litany of them for SQL Server, a few for MySQL and Oracle, but nothing that supports SQL Anywhere correctly. I tried using DB Solo, but it turned all my non-unique indexes into unique ones, and I didn't see any options to change that.

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  • Good tool to visualise database schema?

    - by Mat
    Are there any good tools for visualising a pre-existing database schema? I'm using MySQL if it matters. I'm currently using MySQL Workbench to process an SQL create script dump, but it's clunky, slow and a manual process to drag all the tables about (which would be okay if it wasn't so slow).

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  • What is the best schema design for child collection with a "primary" entity

    - by erg39
    Here is the scenario: You have a Persons table with a one-to-many relationship with an Addresses table, where one of the Address rows is the "primary" Address. Is it better in a normalized schema to Use a Persons.PrimaryAddressID to access the "primary" Address for a Person or Use an Addresses.IsPrimary bit column to reference the "primary" Address for a Person via Addresses.PersonID or Other and why?

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  • Schema to support dynamic properties

    - by Johan Fredrik Varen
    Hi people. I'm working on an editor that enables its users to create "object" definitions in real-time. A definition can contain zero or more properties. A property has a name a type. Once a definition is created, a user can create an object of that definition and set the property values of that object. So by the click of a mouse-button, the user should ie. be able to create a new definition called "Bicycle", and add the property "Size" of type "Numeric". Then another property called "Name" of type "Text", and then another property called "Price" of type "Numeric". Once that is done, the user should be able to create a couple of "Bicycle" objects and fill in the "Name" and "Price" property values of each bike. Now, I've seen this feature in several software products, so it must be a well-known concept. My problem started when I sat down and tried to come up with a DB schema to support this data structure, because I want the property values to be stored using the appropriate column types. Ie. a numeric property value is stored as, say, an INT in the database, and a textual property value is stored as VARCHAR. First, I need a table that will hold all my object definitions: Table obj_defs id | name | ---------------- 1 | "Bicycle" | 2 | "Book" | Then I need a table for holding what sort of properties each object definition should have: Table prop_defs id | obj_def_id | name | type | ------------------------------------ 1 | 1 | "Size" | ? | 2 | 1 | "Name" | ? | 3 | 1 | "Price" | ? | 4 | 2 | "Title" | ? | 5 | 2 | "Author" | ? | 6 | 2 | "ISBN" | ? | I would also need a table that holds each object: Table objects id | created | updated | ------------------------------ 1 | 2011-05-14 | 2011-06-15 | 2 | 2011-05-14 | 2011-06-15 | 3 | 2011-05-14 | 2011-06-15 | Finally, I need a table that will hold the actual property values of each object, and one solution is for this table to have one column for each possible value type, such as this: Table prop_vals id | prop_def_id | object_id | numeric | textual | boolean | ------------------------------------------------------------ 1 | 1 | 1 | 27 | | | 2 | 2 | 1 | | "Trek" | | 3 | 3 | 1 | 1249 | | | 4 | 1 | 2 | 26 | | | 5 | 2 | 2 | | "GT" | | 6 | 3 | 2 | 159 | | | 7 | 4 | 3 | | "It" | | 8 | 5 | 3 | | "King" | | 9 | 6 | 4 | 9 | | | If I implemented this schema, what would the "type" column of the prop_defs table hold? Integers that each map to a column name, varchars that simply hold the column name? Any other possibilities? Would a stored procedure help me out here in some way? And what would the SQL for fetching the "name" property of object 2 look like?

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  • Meshing different systems of keys together in XML Schema

    - by Tom W
    Hello SO, I'd like to ask people's thoughts on an XSD problem I've been pondering. The system I am trying to model is thus: I have a general type that represents some item in a hypothetical model. The type is abstract and will be inherited by all manner of different model objects, so the model is heterogeneous. Furthermore, some types exist only as children of other types. Objects are to be given an identifier, but the scope of uniqueness of this identifier varies. Some objects - we will call them P (for Parent) objects - must have a globally unique identifier. This is straightforward and can use the xs:key schema element. Other objects (we can call them C objects, for Child) are children of a P object and must have an identifier that is unique only in the scope of that parent. For example, object P1 has two children, object C1 and C2, and object P2 has one child, object C3. In this system, the identifiers given could be as follows: P1: 1 (1st P object globally) P2: 2 (2nd P object globally) C1: 1 (1st C object of P1) C2: 2 (2nd C object of P1) C3: 1 (1st C object of P2) I want the identity syntax of every model object to be identical if possible, therefore my first pass at implementing is to define a single type: <xs:complexType name="ModelElement"> <xs:attribute name="IDMode" type="IdentityMode"/> <xs:attribute name="Identifier" type="xs:string"/> </xs:complexType> where the IdentityMode is an enumerated value: <xs:simpleType name="IdentityMode"> <xs:restriction base="xs:string"> <xs:enumeration value="Identified"/> <xs:enumeration value="Indexed"/> <xs:enumeration value="None"/> </xs:restriction> </xs:simpleType> Here "Identified" signifies a global identifier, and "Indexed" indicates an identifier local only to the parent. My question is, how do I enforce these uniqueness conditions using unique, key or other schema elements based on the IdentityMode property of the given subtype of ModelElement?

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  • DEADLOCK_WRAP error when using Berkeley Db in python (bsddb)

    - by JiminyCricket
    I am using a berkdb to store a huge list of key-value pairs but for some reason when i try to access some of the data later i get this error: try: key = 'scrape011201-590652' contenttext = contentdict[key] except: print the error <type 'exceptions.KeyError'> 'scrape011201-590652' in contenttext = contentdict[key]\n', ' File "/usr/lib64/python2.5/bsddb/__init__.py", line 223, in __getitem__\n return _DeadlockWrap(lambda: self.db[key]) # self.db[key]\n', 'File "/usr/lib64/python2.5/bsddb/dbutils.py", line 62, in DeadlockWrap\n return function(*_args, **_kwargs)\n', ' File "/usr/lib64/python2.5/bsddb/__init__.py", line 223, in <lambda>\n return _DeadlockWrap(lambda: self.db[key]) # self.db[key]\n'] I am not sure what DeadlockWrap is but there isnt any other program or process accessing the berkdb or writing to it (as far as i know,) so not sure how we could get a deadlock, if its referring to that. Is it possible that I am trying to access the data to rapidly? I have this function call in a loop, so something like for i in hugelist: #try to get a value from the berkdb #do something with it I am running this with multiple datasets and this error only occurs with one of them, the largest one, not the others.

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  • relating data stored in NoSQL DB to data stored in SQL DB

    - by seanbrant
    Whats the best way to use a SQL DB along side a NoSQL DB? I want to keep my users and other data in postgres but have some data that would be better suited for a NoSQL DB like redis. I see a lot of talk about switching to NoSQL but little talk on integrating it with existing systems. I think it would be foolish to throw the baby out with the bath water and ditch SQL all together, unless it makes things easier to maintain and develop. I'm wondering what the best approach is for relating data stored in SQL to my data in redis. I was thinking of something along the line of this. User object stored in SQL Book object in redis, key sh1 hash of value, value is a JSON string Relations stored in redis, key User.pk:books, value redis set of sha1's Anyone have experience, tips, better ways?

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  • rake db:migrate and rake db:create both work on test database, not development database

    - by geography_guy
    I am new to Stack Overflow and Ruby on Rails. My problem is, when I run the command rake db:create or rake db:migrate, the test database is affected, but the development database is not. rails (3.2.2) my database.yml: # Warning: The database defined as "test" will be erased and # re-generated from your development database when you run "rake". # Do not set this db to the same as development or production. test: &test adapter: postgresql encoding: unicode database: ticketee_test pool: 5 username: ticketee password: my_password_here development: adapter: postgresql encoding: unicode database: ticketee_development pool: 5 username: ticketee password: my_password_here production: adapter: postgresql encoding: unicode database: ticketee_production pool: 5 username: ticketee password: my_password_here cucumber: <<: *test

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  • How to create SQL Server Express DB from SQL Server DB

    - by jeff
    I have a SQL Server 2008 DB. I want to extract SOME tables (and associated schema, constraints, indexes, etc) and create a SQL Server Express DB. It isn't a sync of the target, we stomp on it. We ONLY need to do this in the file system (not across the wire). We are not fond of the synchronization stuff and at this point don't know how to run SSIS. We are a C# shop and a little code is ok. Like using the C# bulk import stuff, but that won't create the schema. Suggestions?

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  • Faking a dynamic schema in Core Data?

    - by Gouldsc
    From reading the Apple Docs on Core Data, I've learned that you should not use Core Data when you need a dynamic schema. If I wanted to provide the user the ability to create their own properties, in a core data model would it work if I created some "dummy" attributes like "custom decimal 1", "custom decimal 2", "custom text 1", "custom text 2" etc that the user could name and use for their own purposes? Obviously this won't work for relationships, but for simple properties it seems like a reasonable workaround. Will creating a bunch of dummy attributes on my entities that go unused by most users noticeably decrease performance for them? Have any of you tried something like this? Thanks!

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  • MongoDB Schema Design - Real-time Chat

    - by Nick
    I'm starting a project which I think will be particularly suited to MongoDB due to the speed and scalability it affords. The module I'm currently interested in is to do with real-time chat. If I was to do this in a traditional RDBMS I'd split it out into: Channel (A channel has many users) User (A user has one channel but many messages) Message (A message has a user) The the purpose of this use case, I'd like to assume that there will be typically 5 channels active at one time, each handling at most 5 messages per second. Specific queries that need to be fast: Fetch new messages (based on an bookmark, time stamp maybe, or an incrementing counter?) Post a message to a channel Verify that a user can post in a channel Bearing in mind that the document limit with MongoDB is 4mb, how would you go about designing the schema? What would yours look like? Are there any gotchas I should watch out for?

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  • Good conventions for embedding schema of a flat file

    - by Ville Koskinen
    We receive lots of data as flat files: delimitted or just fixed length records. It's sometimes hard to find out what the files actually contain. Are there any well established practices for embedding the schema of the file to the beginning or the end of a file to make the file self-explanatory? Just to get an idea, imagine something like this: <data name=test records=2 type=fixed> <field name=foo start=0 length=2 type=numeric> <field name=bar start=2 length=4 type=text> </data> 11test 12ing We would parse the xml in the beginning and use it for reading the records.

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  • Schema Based Code Completion for NetBeans Platform Applications

    - by Geertjan
    Toni's recent blog entry provides, among several other interesting things, instructions for something I've been wanting to cover for a long time, which is schema based code completion: The above is a sample I created via Toni's tutorial, using the schema described here: http://www.w3schools.com/schema/schema_example.asp The support for the Navigator ain't bad either, especially considering I didn't do any coding at all to get all this: And here's where you can find the whole sample: http://java.net/projects/nb-api-samples/sources/api-samples/show/versions/7.2/misc/ShipOrder

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  • xs:choice unbounded list

    - by Matt
    I want to define an XSD schema for an XML document, example below: <?xml version="1.0" encoding="utf-8"?> <view xmlns="http://localhost/model_data" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://localhost/model_data XMLSchemaView.xsd" path="wibble" id="wibble"> <text name="PageTitle">Homepage</text> <text name="Keywords">home foo bar</text> <image name="MainImage"> <description>lolem ipsum</description> <title>i haz it</title> <url>/images/main-image.jpg</url> <type>image/jpeg</type> <alt>alt text for image</alt> <width>400</width> <height>300</height> </image> <link name="TermsAndConditionsLink"> <url>/tnc.html</url> <title>Terms and Conditions</title> <target>_blank</target> </link> </view> There's a view root element and then an unknown number of field elements (of various types). I'm using the following XSD schema: <?xml version="1.0" encoding="utf-8"?> <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns="http://localhost/model_data" targetNamespace="http://localhost/model_data" id="XMLSchema1"> <xs:element name="text" type="text_field"/> <xs:element name="view" type="model_data"/> <xs:complexType name="model_data"> <xs:choice maxOccurs="unbounded"> <xs:element name="text" type="text_field"/> <xs:element name="image" type="image_field"/> <xs:element name="link" type="link_field"/> </xs:choice> <xs:attribute name="path" type="xs:string"/> <xs:attribute name="id" type="xs:string"/> </xs:complexType> <xs:complexType name="image_field"> <xs:all> <xs:element name="description" type="xs:string"/> <xs:element name="title" type="xs:string"/> <xs:element name="type" type="xs:string"/> <xs:element name="url" type="xs:string"/> <xs:element name="alt" type="xs:string"/> <xs:element name="height" type="xs:int"/> <xs:element name="width" type="xs:int"/> </xs:all> <xs:attribute name="name" type="xs:string"/> </xs:complexType> <xs:complexType name="text_field"> <xs:simpleContent> <xs:extension base="xs:string"> <xs:attribute name="name" type="xs:string"/> </xs:extension> </xs:simpleContent> </xs:complexType> <xs:complexType name="link_field"> <xs:all> <xs:element name="target" type="xs:string"/> <xs:element name="title" type="xs:string"/> <xs:element name="url" type="xs:string"/> </xs:all> <xs:attribute name="name" type="xs:string"/> </xs:complexType> </xs:schema> This looks like it should work to me, but it doesn't and I always get the following error: Element <text> is not allowed under element <view>. Reason: The following elements are expected at this location (see below) <text> <image> <link> Error location: view / text Details cvc-model-group: Element <text> unexpected by type 'model_data' of element <view>. cvc-elt.5.2.1: The element <view> is not valid with respect to the actual type definition 'model_data'. I've never really used XSD schemas before, so I'd really appreciate it if someone could point out where I'm going wrong.

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  • Couldn't run loadjava on user schema to load dbwsclientws.jar dbwsclientdb102.jar

    - by padmaja
    I am trying to load oracle webservice client jars to my schema. I did set the PATH to inlcude: /u01/app/oracle/product/10.2.0/db_1/bin When I try to run loadjava as "loadjava -u myschema/myscehmapwd -r -v -f -genmissing dbwsclientws.jar dbwsclientdb102.jar" I am getting error: Exception in thread "main" java.lang.NoClassDefFoundError: oracle/aurora/server/tools/loadjava/LoadJavaMain. Does it mean that jvm is not setup on the box? How can I check if the jvm is enabled or not? I am running it on Oracle 10g in UNIX environment. Any help with the issue is greatly appreciated.

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  • Inheritance in XML Schema definition (XSD) for Java objects

    - by bguiz
    Hi, I need to create an XML schema definition (XSD) that describes Java objects. I was wondering how to do this when the objects in question inherit from a common base class with a type parameter. public abstract class Rule<T> { ... } public abstract class TimeRule extends Rule<XTime> { ... } public abstract class LocationRule extends Rule<Location> { ... } public abstract class IntRule extends Rule<Integer> { ... } .... (where XTime and Location are custom classes define elsewhere) How would I go about constructing an XSD that such that I can have XML nodes that represent each of the subclasses of Rule<T> - without the XSD for each of them repeating their common contents? Thank you!

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