The Latest

DevX - Software Development Resource

Printing a line at the detail band

Question: I want to print a line at the detail band onlyif it’s on the last row of the page; otherwise, itshould not print at all. Answer: To achieve this,

DevX - Software Development Resource

Page allocations in a sql table

Question: I am getting all kinds of errors on a database table that have something to do with page allocation in the database (error 1109). I would like to drop

DevX - Software Development Resource

Socket Buffer Size

Question: How do I set the socket input and output buffer sizes in Java? Answer: You cannot set the socket input and output buffer sizes in Java versions prior to

DevX - Software Development Resource

What is SQL?

Question: What are the types of features available and its respective characteristics? How does this language help in relational databases? Answer: May I suggest you obtain Joe Celko’s introductory book

DevX - Software Development Resource

Cannot index

Question: SQL Server 6.5 does not allow an index to be placed on the bit datatype. Does this affect performance when doing queries that filter on the bit, or are

DevX - Software Development Resource

Using a stored procedure like a subquery

Question: I’m trying to get something like this to work. How can I take the output of a stored procedure and use it in a subquery? create procedure pcore asselect

DevX - Software Development Resource

Documenting my tables, triggers

Question: We use SQL Server 6.5 (7 in a few weeks). I’m looking for a good tool to generate ERDs and overviews of my database tables. Which software can you

DevX - Software Development Resource

pass variables to a pb app

Question: My PowerBuilder application is a contact system. It includes a case-based reasoning system that uses customer account numbers to guide users through actions. I need to be able to

DevX - Software Development Resource

Changing the current directory

Question: How does one change the current working directory of a Java program or a java.lang.Process? The equivalent of the Unix chdir system call seems to be absent. Answer: There

DevX - Software Development Resource

Rich Text Edit – Syntax Highlighting

Question: I’m building an application where the user can type several lines of text and save it to disk (as plain text). It would be nice if some words appeared

DevX - Software Development Resource

Opening an applet socket to the originating server

Question: I have a server application that I want an applet client to connect with. How can the applet determine the address of the originating serverwithout having to hard-code the

DevX - Software Development Resource

Polymorphism

Question: Given a reference to an object B that is a subclass of A and overrides method foo(), is there any way I can invoke the base implementation of foo()

DevX - Software Development Resource

RAND Function

Question: I’m doing a select statement within a stored procedure, which returns several columns. I would like to assign a random number to each column, but when I use the

DevX - Software Development Resource

How Do I Christen This Class?

Good design goes hand in hand with the nomenclature it uses for exchanging that design between developers. A key feature to writing good code consists of good naming conventions and

DevX - Software Development Resource

Checking Whether a Stack Is Empty

It is an error to call the member function pop() on an empty stack. If you are not sure whether a stack contains any elements, you can use the member

DevX - Software Development Resource

Always Initialize Pointers

An uninitialized pointer has an indeterminate value. It’s almost impossible to test subsequently whether such a pointer is valid, especially if it is passed as an argument to a function,

DevX - Software Development Resource

Simplify Creating and Adding Menu Items

When creating menu items and adding them to a menu, you can shorten your code by combining two steps into one. Instead of creating the menu item and adding it

DevX - Software Development Resource

Data Pointers vs. Function Pointers

C and C++ make a clear-cut distinction between two types of pointers: data pointers and function pointers. A function pointer embodies several constituents such as the list of arguments, a

DevX - Software Development Resource

When to Use a Pure Virtual Member Function

A pure virtual function is merely an interface and can be thought of as a way to enforce policy. A pure virtual function should be used when subclasses implement the

DevX - Software Development Resource

Integer Affixes

You can use affixes to help the compiler figure out the correct type of a hard coded integer. The letter L affixed to a number indicates a long integer and

DevX - Software Development Resource

Elaborated Type Specifier

An elaborated type specifier is a type name preceded by one of the keywords: enum, struct, union, and class. You can use an elaborated type specifier to instantiate an object

DevX - Software Development Resource

Using bsearch the Right Way

Standard C defines the function bsearch, which performs a binary search on an array of elements. The function bsearch is very efficient, but it works only on sorted arrays. You

DevX - Software Development Resource

The Perils of a Container’s Reallocation

When a container reallocates its elements, their addresses change correspondingly. Consequently, the values of existing iterators are invalidated: #include #include using namespace std;void main() { list payroll; payroll.push_back(5000.00); list::iterator p

DevX - Software Development Resource

Pointers to Members of a Template Class

You can define a pointer to a class template member. For example, you can use the specialization vector: typedef void (vector< int >::*v_vi_szt) (size_t); // v_vi_szt is used to hide

DevX - Software Development Resource

The begin() and end() Member Functions of STL Containers

All STL (Standard Template Library) containers provide the begin()/end() pair of member functions. The member function begin() returns an iterator that points to the first element of the container: vector