Update. Since the version 2016 SQL Server supports anonymous constraint declaration:

CREATE TABLE #temp_table (
   id1 int NOT NULL,
   id2 int NOT NULL,
   name1 nvarchar(100),
   name2 nvarchar(100),
   PRIMARY KEY (id1, id2),
   UNIQUE (name1, name2)
);

For earlier versions the solution is below.

Local temporary tables are isolated in the scope …

Unfortunately, SQL Server doesn't have a function like frac to extract the fractional part of number. The method is to subtract the integer part from the origin value.

DECLARE @n1 float, @n2 float, @n3 float;
SELECT @n1 = 123.456, @n2 = 234.567, @n3 = 456.789;
SELECT @n1 - round(@n1, 0 …

Collection of methods to generate random string in a single SQL statement

M1: Recursive string concatenation

On SQL Server the method is limited by 100 characters because of CTE recursion level limitation. The method has the performance issues when using in loops/joins because the table always have 100 rows …

This small example shows how to synchronize the data of two tables using the MERGE statement

CREATE TABLE table1 (id int NOT NULL PRIMARY KEY, str_value nvarchar(50));
CREATE TABLE table2 (id int NOT NULL PRIMARY KEY, str_value nvarchar(50));
GO
INSERT INTO table1 (id, str_value) VALUES (1, 'Value 1 …

Notepad++ can count LOC (lines of code) of source files and give you the estimation of code size.

Press Ctrl+Shift+F shortcut to start "Find in files" dialog. Select "regular expression" search mode and start it.

Some regular expressions:

• \S+\s*$ -- all non-empty lines
• ^\s*$ -- only empty (white-space) lines …

This article is used in my book "Programming with databases".

Better to see once than to hear a hundred times. This small article explains what are the different kinds of joins in SQL.

At the first time you should take into account that SQL is a declarative 4th generation language …

Since early XE versions C++ Builder supports Delphi units directly added in C++ project and compiles them as well as C/C++ source. However, this approach has several drawbacks:

• Usually, Delphi files are stored in separated folders of other applications and packages. So your C++ project will point to many …

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 …

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 …

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 …