SQL Server: fractional part of number

| category: Programming | author: st
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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 …

SQL: generate random character string

| category: Programming | author: st
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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 …

SQL Server: sync two tables with MERGE statement

| category: Programming | author: st
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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 …

Count LOC with Notepad++

| category: Programming | author: st

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.

Notepad++ LOC count

Some regular expressions:

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

Using Delphi library with C++ Builder

| category: Programming | author: st
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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 …

Interface implementations and multiple inheritance in C++

| category: Programming | author: st
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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 …