Oracle8i has introduced database-level and system-level triggers. They can track events in the database such as logon/logoff from a schema, startup and shutdown of a database, and response to a

A temporary table has a definition or structure like that of a regular table, but the data it contains exists for only the duration of a transaction or session. Oracle8i

Oracle comes with a PL/SQL wrapper, which converts the PL/SQL source code into an intermediate form of object code. By hiding application internals, the wrapper prevents the misuse of your

If you have a table whose columns always are queried together, maybe you should store them as an index-organized table (IOT). An IOT is indexed on one or more columns

If you have a database function that has multiple return statements, try to minimize the exit points. I will explain with the following example: create or replace function getStatus(p_status_code in

Question: How do I make a beep in C++? I’d like to make my program alert the user in case of errors. Answer: Use the ‘a’ escape sequence to emit

Question: How can I run an Informix SQL Script from the Linux Operating System command line directly? Answer: Use this format: dbaccess The is the name of the database and

Question: Why doesn’t the datatype called sysname show up in all the tables’ dropdown lists of datatypes? Answer: The sysname datatype is a system datatype used to store database object

Question: I was trying to test a base class and I came across an unusual question: in the below code, why doesn’t the compiler complain about the return code type

The C++ standard doesn’t specify the maximal number of member functions that a class can have. However, it recommends that it be 4096. Normally, classes don’t have more than 15-25

I received an interesting question from a reader. He used STL’s vector in a class that was heavily used in his project. The two compilers he used produced an extremely

I often receive readers’ queries regarding non-standard header files that they don’t have in their development suite, e.g.,,, that they wish to install. This header chase is futile

Do the following declarations differ in any way from one another? const long int N=0;long const int N=0; No, they don’t. C and C++ do not enforce a specific order

You can apply operator dynamic_cast only to polymorphic objects (a polymorphic object is one that has at least one virtual member function). This is a requirement of the C++ standard.

Question: I have some orphaned Exchange mailboxes that are displayed under Private Information Store/Mailbox Resources. How do I remove them if the object is not defined in the DS? Answer:

The standard DAO Data control is designed to work with the Jet 3.5 Engine, whereas Access 2000 database can be accessed only by the more recent Jet 3.6 engine. For

Date variables store values in floating point format, much like Double variables, with the integer part for dates and the fractional part for the time portion. Being floating point values,

If your ASP pages display strings stored in database fields, you should always process the strings with the Server.HTMLEncode method, otherwise the string won’t be displayed correctly in the user’s

After you install Visual Basic and log on to the machine as a different user (with or without administrator privileges), you cannot see any Add-Ins in the Add-In dialog in

Have you ever read a message like “Dependency file for COMCTL32.OCX is out of date” during the package creation process? The cause of this problem is simple: you have installed

When you assign a reference to a form (or one of its controls) to an object variable which is stored outside the form module, you must set the variable to

If you instantiate an ActiveX component from an ASP script under IIS 4 and previous versions, using the Server.CreateObject command, you might believe that the object is deallocated as soon

A SELECT query returns all the rows for which the WHERE clause returns True. However, many developer – especially those accustomed to other programming languages, such as VB – get

In SQL Server 6.5 and previous versions, the GROUP BY clause in a SELECT statement was carried out by temporarily sorting the resultset before grouping similar rows, therefore the end

One of the resource dispensers that come with MTS is Shared Property Manager (SPM). SPM provides a mechanism by which you can share global memory among all the objects that

Question: According to the stats of my Web site, there are still quite a few users who use old browsers like Netscape 3.0 and Explorer 3.0. If I start using

Question: I am using a disconnected recordset (adOpenStatic, adUseClient) which is obtained by executing a stored procedure using command an object. I tried to delete some fields from the recodset

Question: Can Javascript code be used in XHTML Web pages? Answer: Sure. The only real difference between XHTML and HTML is the consideration for ampersands and less than symbols. Thus,

Question: When I try to send some information to an access database through ASP, I get the following error: [Microsoft][ODBC Microsoft Access 97 Driver] Field ‘tablename.class’ can’t be a zero-length

Question: What is the difference between SOX schemas and XDR schemas? Answer: SOX schemas are more object-oriented (the name in fact means Schemas for Object-Oriented XML), allowing you to assign