Here are some examples of SQL to generate a sequence of numeric (integer) values from 0 to 99.

ANSI-compatible

SELECT ones.n1 + tens.n2 * 10
FROM
(
  SELECT 0 AS n1
  UNION SELECT 1 AS n1
  UNION SELECT 2 AS n1
  UNION SELECT 3 AS n1
  UNION SELECT 4 AS n1 …

Some countries have integer numbers printed on the transport tickets, for example, in ex-USSR. The ticket is "happy" when the sum of the first half of digits equals to the second one. Then you should eat it and make a wish.

Example:

123456 and 111222 are not happy tickets
123123 …

How to install and use Delphi 7 and help files on Windows 8/10 or Server 2012.

Installation

Start Delphi setup and install all required items including help files.

In Windows 8/10/Server 2012 or later (should work on Windows 7 too):

• Create the shortcut to Delphi32.exe
• Open …

Here is the code explaining some methods to pack bit accessing logic in your program.

program project1;

type
  TRec1 = packed record // Doesn't pack at all
    b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13, b14, b15, b16: boolean;
  end;

  TRec2 = bitpacked record // Free Pascal specific …

As DBAs know, Database Tuning Advisor can help you in some cases.

• The analyze of the traces will be efficient in OLTP where the most of queries are repeating and could be generalized
• The analyze of traces will be less efficient in OLAP/reporting where the queries are parameterized by …

In theory, hash map structure should be very fast on retrieving by key operations, close to O(1) like for an array. A sorted map (keys are sorted) should be O(log₂ N) instead. The following test checks the difference.

Common scenario

We will use one tester class per …

Free Pascal (like Delphi) provide some useful functions to watch heap memory state in your application.

function GetHeapStatus: THeapStatus;

THeapStatus is documented here

Example of using this function is below

program ProgWatchMem;

uses
  Math, FGL;

type
  TLongIntArr = array of LongInt; // LongInt is a 4-byte signed integer
  PLongIntArr = ^TLongIntArr;
  TMySortedMap = specialize …

In the previous article "Crack C# namespaces in 30 seconds" I demonstrated how to make error having no idea about it. So you will have a lovely time in debugging. But in C# you're condemned to use using directive or your code will be unreadable with all these horrible specifiers …

Multiple inheritance of interfaces which are pure abstract classes indeed is not a problem until you need to use the interface implementation in other classes.

Suppose there are two interfaces, the implementation of which will be used in other classes.

class IA
{
public:
    virtual void m1() = 0;
};

class IB : public …

GenieLamp is the software factory and model-driven development framework. You have no more to write a boilerplate!

Quick start on the project's wiki.

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