Some Linux-commands for work with archives from command line. In this tutorial we have this structure (Figure 1 and Figure 2): /home/alexey/Documents/mydir/ - is a directory for adding to archive. (more...)

It’s a little tutorial about how to get all duplicate records on namesakes example from your database table. For example, we have a table with columns Id, FullName, Birthdate and Phone.

Using 'GROUP BY' and 'HAVING' we can select all namesakes.  (more...)

Concatenating of string columns is not very simple task in T-SQL if you don’t know ANSI standart of it. According to ANSI standart of SQL, concatenating of NULL-value is NULL in the result. It’s not clearly for developer, but it is so.

Let’s see some features for work with concatenating NULL-value columns. For example, I will use tutorial database Northwind and its table Customers. (more...)

This post is about which string functions there are in Transact-SQL. They allow to modify data you have, make custom queries to select records from database tables. To know them is very important for any developer - using string functions is very good way to decrease load from application server without adding it to SQL because string functions on SQL server work very fast. (more...)

Another way for using conditions in Transact-SQL besides IF…ELSE is CASE operator. The syntax is some different from IF…ELSE but in some cases more readable. CASE also uses the word "THEN". (more...)

On Microsoft.com you can download Microsoft® SQL Server® 2012 Express. It’s a free software for home use – education, tests or something like this. When you click "Download" link on a page  http://www.microsoft.com/en-US/download/details.aspx?id=29062, you can see a list of versions for downloading. Which one to choose? (more...)

In this post I will write about SQL conditions. It seems to me that construction "IF ... ELSE" you can find in any language. Transact SQL is not exclusion.

Let’s see IF ... ELSE in action on the sample below. (more...)

There are two functions for converting SQL data types from one to another. They are CAST and CONVERT. The second function is the best solution for converting datetime to format you need. (more...)

There are several ways to make a copy of database table in MS SQL Server. I write down some ways to make a copy of table. Which way to choose is your choice according to table structure, indexes and your wish to make something manually. (more...)

I don’t often use SQL queries but sometimes I have to. And every time it’s the same – I use search engines to find documentation, especially about work with datetime fields. During these readings I found out at least 3 ways to select records with date I need.

(more...)