Question: How do I test the number of ‘characters’ contained within a given variable? Answer: Try this: Debug.Print “Length: ” & Len(CStr(X)) Once you convert a variable to a string,

Question: How do I use the ADO events FetchProgress or FetchComplete? Answer: If you want to use these, they work just like other events generated by other objects. When you

Question: What is the proper syntax to insert a column into an existing SQL table? Answer: Here’s the syntax to add a column to a table: ALTER TABLE Employees ADD

Question: Using a single datawindow, can I access data from multiple databases (Oracle and Sybase)? If not, can I use PowerBuilder to access it without having any intermediate table? Answer:

STL’s unique() algorithm eliminates all but the first element from every consecutive group of equal elements in a sequence of elements. unique() takes two forward iterators, the first of which

A bit field can be signed or unsigned. According to the C++ standard, a signed bit field may be represented in one of three ways: two’s complement one’s complement sign

Although usually I don’t recommend using macros in C++ code, there are a few exceptions. One such exception is when you want to create a truly immutable constant. Consider the

If you happen to define an object or a function or a constant whose name collides with a macro located elsewhere in a third-party header file, as in: // file

Open source products come with their source code files. Although you can usually install a ready-made executable file, you want to take advantage of the available source code files and

Many modern operating systems support Symmetric Multiprocessing (SMP)?a hardware architecture that uses two or more processors on one machine and enables you to achieve true multitasking. On SMP architectures, multithreaded

The members of an enumerated type are called enumerators. For example: enum Direction { Up, // an enumerator Down // another enumerator }; int main() {} An enumerator’s scope is

I receive many questions from readers asking for guidance on how to port an existing C++ app to a different compiler or platform. Porting software can be very easy or

On modern operating systems, a process consists of an executable file that the OS loads into the system’s memory and executes. A process normally has an entry point and one

Question: How do I drop a table column? Answer: To drop a column, use this syntax: ALTER TABLE Employees DROP COLUMN HomePhone Just remember that you can’t drop a column

Question: How do I create a constructor for a protected member of a class? I have declared the function in the header file but not defined the definition.The error message

Question: I need a query that retrieves info from an Oracle table and a query that retrieves info from a SQL Server table. The info has to be joined together

Question: What are the differences between Provider=MSDASQL.1 and Provider=SQLOLEDB.1 in an “Open” “Select” statement? Also, what is the difference (if any) between “ADO” AND “OLE/DB”? And finally, in Visual Basic,

Question: I have two questions: 1. How can I determine what the server’s lock mode currently is (e.g. WAIT, NO WAIT, etc.), without actually setting it at the same time?

Question: What’s the syntax for outer joins in the where clause in Informix? Answer: The syntax is: SELECT c.customer_num, c.lname, c.company,c.phone, u.call_dtime, u.call_descrFROM customer c, OUTER cust_calls uWHERE c.customer_num =

Question: Using C or C++ for CGI programs, is there a way to make a CGI program that calls another CGI program, and then takes the output of that called

Question: If I have the option of using the uniqueidentifier or int data type for a primary key, will choosing the uniqueidentifier mean a significant performance degradation? Answer: The uniqueidentifier

Const HKEY_LOCAL_MACHINE = &H80000002′ Return information about the Bios (NT only)” Requires the GetRegistryValue routineSub GetBiosInfo(BiosDate As String, BiosVersion As String) ‘ These keys appear to exist only on NT

Private Declare Function GetVersion Lib “kernel32″ () As LongConst HKEY_LOCAL_MACHINE = &H80000002′ Modify the name of the registered user and organization” Requires the SetRegistryValue functionSub SetRegisteredUser(ByVal UserName As String, Optional

Const HKEY_LOCAL_MACHINE = &H80000002′ Information about the CPU’ you can pass a number 1 to the last argument to retrieve’ information on all the processors in a multi-CPU system” Returns

Const HKEY_LOCAL_MACHINE = &H80000002′ modify the value of a setting for the VB IDE from the Registry’ Important: only works with VB6” New values are effective when VB is restarted”

Const HKEY_LOCAL_MACHINE = &H80000002′ Get the path of a Windows application’ or an empty string if the application isn’t registered” this routine only works for those applications that register’ themselves

Const HKEY_LOCAL_MACHINE = &H80000002′ read the name and path of the external HTML editor’ configured for the VB environment” Requires the GetRegistryValue functionFunction GetExternalHTMLEditor() As String ‘ Note that the

Const HKEY_LOCAL_MACHINE = &H80000002′ get the list of ODBC drivers through the registry” returns a collection of strings, each one holding the’ name of a driver, e.g. “Microsoft Access Driver