It’s less important which exact conventions you choose to follow – but this page has a few suggestions.

The benefits of using a naming convention are more to do with human factors than any system limitations – but this does not make them any less important.

Table Names

Table names are plural, field name is singular

Table names should not contain spaces, words should be split_up_with_underscores.

The table name is limited to 30 bytes which should equal a 30 character name (try a DESC ALL_TABLES and note the size of the Table_Name column)

If the table name contains serveral words, only the last one should be plural:
APPLICATIONS
APPLICATION_FUNCTIONS
APPLICATION_FUNCTION_ROLES

There are pros and cons to adding a prefix or suffix to identify tables-

Pros: If most access will be made via VIEWS then prefixing all the tables with T_ and all the views with V_ keeps things organised neatly, you will never accidentally query the wrong one.

Cons: Suppose, your naming convention is to have the ‘_TAB’ suffix for all tables. According to that naming convention, the APPLICATIONS table would be called APPLICATIONS_TAB. If as time goes by, your application gets a second login, perhaps for auditing, or for security reasons. To avoid code changes, you will then have to create a View or Synonym that points at the original tables and is confusingly called APPLICATIONS_TAB.

Of course if all your code was written against Views in the first place then you skirt right around that issue.

Field Names

Ideally each field name should be unique within the database schema. This makes it easy to search through a large set of code (or documentation) and find all occurences of the field name.

The convention is to prefix the fieldname with a 2 or 3 character contraction of the table name e.g.

PATIENT_OPTIONS would have a field called po_patient_option

PATIENT_RELATIVES would have a field called pr_relative_name

ABSENCES would have a field called ab_start_date

In a large schema you will often find two tables having similar names which could result in the same prefix. You can avoid this by thinking carefully about the name you give each table – and documenting the prefixes to be used.

For very complex systems (thousands of tables) consider alternatives e.g. a prefix/suffix to identify the Application module.

Keeping names short: Oracle places no limit on the number of columns in a GROUP BY clause or the number of sort specifications in an ORDER BY clause. However, the sum of the sizes of all such expressions is limited to the size of an Oracle data block (specified by the initialization parameter DB_BLOCK_SIZE) minus some overhead.

Primary Key Fields - indicate by appending _pk

e.g.

PATIENTS would have a primary key called pa_patient_id_pk

REGIONS would have a primary key called re_region_id_pk

And so on…the name of the primary key field being a singular version of the table name. Other tables containing this as a foreign key would omit the _PK

so
CLINIC_ATTENDANCE might then have a foreign key called ca_patient_id
or alternatively: ca_patient_id_fk

Tables with Compound PK’s, use _ck in place of _pk

Notice that where several tables use the same PK as part of a compound foreign key then the only unique part of the FK fieldname will be the table prefix.

View Names

View names are plural, field name is singular

View names should not contain spaces, words should be split_up_with_underscores.

While it is common to prefix (or suffix) all views with V_ or VW_, a strong argument can be made that neither are really needed.

One of the easiest ways to boost the performance of an application is to provide, at an early stage in the design, a carefully tuned set of views, then write all the application code against those Views.
Giving your Views friendly easy names will promote their use by developers and end-users, this in turn will mean fewer badly written queries and more use of ’shared SQL’ which will improve the cache hit ratio.

For very large systems, it can make sense to prefix tables/views with the application module name, so a database holding data for both Widget Production and Human Resources data might prefix everything with either HR_ or WP_

Index names

Name the Primary Key index as idx_<TableName>_pk

e.g.
PATIENTS would have a primary key index called idx_patients_pk

Name a Unique Index as idx_<TableName>_uk

e.g.
PATIENTS would have a unique index called idx_patients_uk

Where more indexes are added to the same table, simply append a numeric:

idx_<TableName>_##

Where ## is a simple number

e.g.
PATIENTS would have additional indexes called idx_patients_01, idx_patients_02,…

Note – Conventions that attempt to use the column name as part of the index name become unmanageable as soon as you have multiple columns appearing in multiple indexes.

Constraints

Primary and Unique constraints will be explicitly named.

Name the Primary Key Constraint as pk_<TableName>

e.g.
PATIENTS would have a primary key index called pk_patients

Name a Foreign Key Constraint as fk_<TableName>

e.g.
PATIENTS would have a Foreign Key constraint called fk_patients

Note – in general each constraint should have a similar name to the index used to support the constraint.

Other Fields

Without getting carried away, you can also apply a suffix to non key fields where this is helpful in describing the type of data being stored.
e.g.
A column used to store boolean (Yes/No) values can be given a _yn suffix: retired_yn, superuser _yn, driver_yn

In lookup tables an easy way to identify the main text field is to name it as a singular version of the tablename
e.g.

asset_types.at_asset_type_id_pk   (Primary Key)
asset_types.at_asset_type         (Text field)
asset_types.at_network_yn         (boolean)

SQL

Type all SQL statements in lowercase, being consistent with capitalisation improves the caching of SQL statements. A common variant is to put only SQL keywords in capitals.

SELECT
   em_employee_id_pk,
   em_employee,
   ab_start_date
FROM
   employees em,
   absences ab
WHERE
   absences.ab_employee_id=employees.em_employee_id_pk;

You already have a unique prefix worked out for every table, so use the same thing when an ALIAS is required – this makes the SQL much easier to read.

Always list tables in the FROM / WHERE clause in desired join order – even with CBO you are giving the Query Optimiser less work to do.

PL/SQL

Prefix scalar variable names with v_
Prefix global variables (including host or bind variables) with g_
Prefix constants with c_
Prefix procedure or function call parameters (including sql*plus substitution parameters) with p_

Prefix record collections with r_ (alternatively suffix with _record)
Prefix %rowtype% collections with rt_ (alternatively suffix with _record_type)

Prefix pl/sql tables with t_ (alternatively suffix with _table)
Prefix table types with tt_ (alternatively suffix with _table_type)

Suffix cursors with _cursor
Prefix exceptions with e_

If a pl/sql variable is identical to the name of a column in the table Oracle will interpret the name as a column name.

Packages
Prefix package names with PKG_

Write one package for each table – named PKG_TABLENAME, put all other code that logically belongs to the schema, but not to any particular table in a single Schema package PKG_SCHEMANAME.
If, as is likely, more complex grants are required for different groups of users then create an additional package for each workgroup – these should contain no code just wrappers that call procedures/functions in the other packages.
This gives a level of separation between the basic code and the user security/grants and makes it easier to change one without breaking the other.

A pl/sql function name like PAYROLL.TAX_RATE the word PAYROLL could refer to either a schema or a package name.

Edit Replace

If you apply a naming convention and then decide to rename something it may be possible to use Edit-Replace to update the associated code. But consider these two fieldnames:

area_codes.ac_code
region_area_codes.rac_code

The columns may be unique but one is a substring of the other!

Instance

Oracle database instance names are limited to eight characters. The first two or three characters of the name should reflect the Application, with the remainder indicating the nature of the instance.
e.g.

Live instance   SSLive
Test instance   SSTest
Train instance  SSTrain
Data Warehouse  SSdw
Staging Area    SSsa

Data Files

Name Data files so that they identify the instance and the tablespace.

Each filename should end with a two digit numeric value starting with 01, that is incremented by 1 for each new datafile added to the tablespace.
Use the extension “.dbf”
e.g.

SSLive_temp01.dbf
SSLive_rbs01.dbf
SSLive_clinical01.dbf
SSLive_clinical02.dbf

Tablespaces

Avoid naming tablespaces according to time periods.
(Oracle never forgets a tablespace and SMON will scan the list of tablespaces in TS$ every 5 minutes) For a partitioned datawarehouse, try to adopt a strategy of recycling the tablespace names.

Redo Logs

The redo log is a separate file (not in the tablespace)
Name Redo Logs so that they identify the instance, group and member number of the log. Use the extension “.log”
e.g.
SSLive_redo_01.log

For more detail on the physical placement of files see Oracle Optimal Flexible Architecture (OFA)

Documentation

Lastly – write and maintain a data dictionary for all data elements – rather than just dumping the Oracle data dictionary into a text document or an Entity relationship diagram – you should also be defining the business meaning of each data item.

Summary

RDBMS naming conventions can become the subject of endless debate – here are a few last things to consider:

Does your naming convention make names longer or shorter?

PURCHASE_ORDER_DATE versus PO_DATE

Will you have novice users writing SQL against the database?
If so will they understand the meaning of things like PO_DATE

Is the naming convention documented somewhere that everyone can find? If you arent planning to change it very often, drop the text right into a tableSELECT * from Naming_Conventions;

Related:

Ask Tom – Argues against the column prefix
Oracle-Base.com Naming conventions
SQL convention from Philip Greenspun
Reddick Naming convention (hungarian notation)
Joe Celko – 10 Bad Habits
SQL Server Naming conventions
Oriolecorp – File Naming, password conventions
SQL formatter – Online SQL beautifier
Q189220 – Microsoft support for spaces in fieldnames
Standard ISO-11179 – Rules for defining data elements
Optimal Flexible Architecture (OFA)

Below is a diagram I draw based on the MSDN Table-per-type sample. The right side is a list of entity types in the source layer while the left side is a list of entity types in the entity layer ( or conceptual layer). In the conceptual layer, the DeptMusic, DeptEnginerring and DeptBussiness are derived from base type Department. That is, four tables have corresponding entity types. Therefore this inheritance solution is called Table-per-type ( TPT ). Although the Department and DeptBusiness tables have no relationship with each other, the primary keys of these tables are mapped to the same DepartmentID of the Department base type.

Table-per-hierarchy ( TPH ) is another way to create inheritance entity model in the EDM. The MSDN sample uses one person to hold the persisted data from the Student, Administrator, instructor and Person entities. As you might notice, Person is the base type in the hierarchy while Student, Administrator and Instructor are derived types. The PersonCategory column of the Person table is called discriminator column. If the value of PersonCategory is 0 in the database, when the data is materialized to object via Entity Framework, a person object will be created. A value of 1,2,3 indicate the Student, Instructor and Administrator types respectively. You can use Entity Mapping Detail window to specify discriminator columns and values.

source http://lwang00.wordpress.com/2007/11/04/entity-mapping-table-per-type-and-table-per-hierarchy/

class User  {
String firstName
String surName
Short  age
static constraints = {
firstName(blank: false, maxSize: 150)
surName(blank: false, maxSize: 150)
age(min: 18 as Short, max: 99 as Short)
}
}

In order to implement custom constraints like i.e. an age constraint, which encapsulates the constraint’s implementation you could extend from Grail’s AbstractConstraint class. The problem with this approach is, that you than need to register your custom constraint at bootstrap, to use it in every possible scenario (going from testing to running the app).

Fortunately there is a plugin that helps with creating custom constraints: the constraints plugin.

grails install-plugin constraints

Installs the plugin and adds a dependency entry in your application or plugin settings. If installation was successful your grails help command lists the create-constraint command, that from now can be used to create custom constraints.

Creating an application-specific age constraint would be as simple as:

grails create-constraint Age

which creates grails-app/utils/AgeConstraint which i modified to be

class AgeConstraint {
def validate = { propertyValue ->
return propertyValue >= 18 && propertyValue <= 99
}
}

After declaring the constraint it can be used in domain or command classes:

class User  {
String firstName
String surName
Short  age

static constraints = {
firstName(blank: false, maxSize: 150)
surName(blank: false, maxSize: 150)
age(age: true)
}
}

If you take a look at the plugin’s documentation [0] there are several to use default message codes for i18n of error messages and so on. But this plugin works perfectly for adding custom constraints to your Grails environment.

[0] Constraints Plugin - http://github.com/geofflane/grails-constraints

sudo vi /etc/paths

1. Download the latest dmg from http://code.google.com/p/red5/
2. Open the package, drag Red5 to your Applications folder, then start the app (nothing happens visually, it’s a server!)
3. Open http://127.0.0.1:5080/demos/ in a browser, which should hopefully now show you the demo page

The next step is to install the demos you want to try using a flash control panel that comes packaged with the distribution. Now, be warned, as of version 0.9.0 RC2, the distribution is a little flaky. So when you click the link to “install” demos on the page you just loaded, it won’t work.

So if the link doesn’t work for you, try http://127.0.0.1:5080/installer/ instead! Go back to the first page to access the demo you installed.

Finally use a terminal session to browse inside your app folder (i.e. inside /Applications/Red5.app) and have a poke around the underlying code and configurations.

/Applications/Red5.app/Contents/Resources/Java/webapps is a good place to start. You’ll notice that the system packs Tomcat, and the distribution acts as a web server.

source http://ria101.wordpress.com

When copying files from one location to another, I have always found it an annoying process to drag the files to one location and then go back and delete them from the original location.

The default drag and drop process in OS X is to COPY files.

We want to be able to MOVE files.

To MOVE a file is to actually copy files to a new location and to delete them from the original location.

OS X will move the file if you hold the CMD key while you drag and drop.

One caveat:

Something that confuses people is what happens if duplicate files are found during the move drag and drop. If you release the CMD key to answer the dialog box that appears, the file will be copied but not moved. If you continue to hold the CMD key as you click the Replace button, the move action will be completed.

source http://www.tech-recipes.com/rx/2581/os_x_move_files_instead_copying/

At the home screen of your Berry
press: alt + shift + h

this is what gonna appear

Your PIN will be shown, but If the PIN: Suspended, means u can’t use BlackBerry Internet Service. Don’t Buy it!!!

To Check Your Device Voice/Data Usage:

A Brand New item should not exceed the limit

Go to: Options > Status > Type: BUYR (for qwerty KeyPad)

Go to: Options > Status > Type: BUZR (for qwertz KeyPad)

Definitely Brand New Device

Not Brand New

If The usage not exceed, perhaps is just for testing purposes

To Check Your Device Locked or Unlocked:

Go to: Options > Advanced Options > SIM CARD > Type: MEPD

Device Locked by Provider

Device Fully Unlocked

Enterprise Activation (Options->Advanced)
ALT+CNFG – Settings for Enterprise Activation

Address Book
ALT+VALD – Validate the data structure and look for inconsistencies
ALT+RBLD – Force a data structure rebuild

from the Options menu, type the following (No ALT+ required)
RSET – Will prompt to erase & reload for a reload of the Address book from the BES
(n.b. this will wipe all entries, but you can goto SIM Phone Book & copy entries back afterwards)

Browser
ALT+RBVS – View web page source code

Calendar
Open up a Calendar item
ALT+VIEW Inside any Calendar item Show extra info for a Calendar event
(including message ID – handy for BES log troubleshooting)

from the Options menu, type the following (No ALT+ required)
SYNC – Enable Calendar slow sync
RSET – Will prompt for a reload of the calendar from the BES
RCFG – Request BES configuration
SCFG – Send device configuration
DCFG – Get CICAL configuration
SUPD – Enable detailed Cal. report for backup
SUPS – Disable detailed Cal. report for backup
SUPN – Disable Cal. report database
LUID – Enable view by UID
SRSL – Show Reminder status log

Messaging
ALT+VIEW – For messages, displays the RefId and FolderId for that particular message. For PIM items, displays only the RefId.

Search Application
ALT+ADVM Search Application Enabled Advanced Global Search

Home Screen
ALT(left)+Shift(right)+Del – Restart the Blackberry (only for full-keyboard Blackberries)
ALT+JKVV – Display cause of PDP reject
ALT+CAP+ H – Displays the Help Me screen
ALT + EACE – Displays the Help Me screen
ALT + ESCR – Displays the Help Me screen
ALT + NMLL – Switches the signal strength from bars to a numeric value.
ALT + LGLG – Displays the Java™ event log.

WLAN (WLAN wizard screen)
ALT-SMON WLAN – Enable simulated Wizard mode
ALT-SMOF WLAN – Disable simulated Wizard mode

Theme (from theme menu)
ALT-THMN – Change to no theme (B&W)
ALT-THMD – Change to default theme

Date/Time (Date/Time menu – No ALT+ required)
LOLO – Date/Time Show Network time values

SIM Card (Options->Advanced->SIM card – No ALT+ required)
MEPD – Display MEP info
MEP1 – Disable SIM personalization
MEP2 – Disable Network personalization
MEP3 – Disable Network subset personalization
MEP4 – Disable Service provider personalization
MEP5 – Disable Corporate personalization

Status (Options->Status)
BUYR – Data & Voice Usage
TEST – start a device test (Keyboard, GPS, RF, Audio (Handset,headset,bluetooth, Misc)

source http://ryanfarley.com

ก็เลยกะว่างานนี้เขียนสั่นๆ เอา Groovy ดีกว่า ก็เลยเริ่มจาก start groovy console (run>cmd>groovyConsole ) จากนั้นก็เริ่มเขียน code

ทันใดนั้นนึงขึ้นมาได้ว่า กูจะ add jar ยังไงว่ะ ไม่ได้ start เป็น project เอ้ หรือว่า จะไปสร้าง classpath ยังไงละเนี่ย ก็เลยลองไปหาว่าเจ้า Groovy Console มันจะ add classpath ได้ไงบ้าง

ไปเจอที่บอกว่าให้แก groovy start แต่เอ้ มันไม่เท่อ่ะ ไหน groovy บอกว่าตัวเองเป็น dynamic ก็นึกว่ามันจะเอา env ข้างๆมาให้ด้วย เลยเอา jar ไปวางใน Folder ที่ทำการสั่ง groovyConsole (ในใจนึงว่ามันจะเหมือน grails console) เอ๋ ไม่ได้นี่นา

ไม่ไหวแระ ไหนๆก็ไหนๆ เลยลองเขียน ให้ JAVA มันโหลด JAR แบบ on the fly เลยละกัน ไม่อยากเขียน cmd ไป เรียก class

public static void dynmicLoadJar() {
	File libFolder = new File("libs");
	System.out.println("folder: " +libFolder.getAbsolutePath());
 
	File[] jars = libFolder.listFiles();
	System.out.println("jar: " + jars);
	List<URL> urls = new ArrayList<URL>();
	for (int i = 0; i < jars.length; i++) {
		if (jars[i].toString().contains(".jar")) {
			try {
				urls.add(jars[i].toURL());
			} catch (MalformedURLException e) {
				e.printStackTrace();
			}
		}
	}
 
	for (URL url : urls) {
		try {
			System.out.println("Dynamic add " + url.toString() + " to class path");
			URLClassLoader classLoader = (URLClassLoader) ClassLoader.getSystemClassLoader();
			Class clazz = URLClassLoader.class;
			Method method = clazz.getDeclaredMethod("addURL", new Class[]{URL.class});
			method.setAccessible(true);
			method.invoke(classLoader, new Object[]{url});
			Thread.currentThread().getContextClassLoader().getResourceAsStream("context.xml");
		} catch (Exception ex) {
			System.err.println("Error when dynamic load jar");
			ex.printStackTrace();
		}
	}
}

ซึ่งจะทำการโหลด JAR ที่อยู่ใน folder libs มาให้เอง โดยใช้ reflection ยัดเข้าไปใน URLClassLoader ของ Java