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Databases Have Beautiful Structure

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Introduction

One of the biggest issues beginning SQL writers have is being able to write queries that use more than one table.  In this series of articles we are going to show you how to write a query that combines, or joins, data from more than one table. Once you have gone through the examples you will understand how to write the basic commands to make this happen and why data is separated in the first place.

This first article introduces the concept of joining tables.  The focus is going to be more on the type of joins, not necessarily their syntax.  The later articles focus on the various types of joins.  Through the narrative and examples you’ll become very comfortable with each one.

In my prior articles you learned about the need to normalize to make it easier to maintain the data.  Though this makes it easier to maintain and update the data, it makes it very inconvenient to view and report information.  Typically the information you need to see has to be cross referenced across several tables for you to see the full picture. [click to continue…]

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circlepattern

This is the second of four articles in a series explaining the three simple steps I take to writing complex SQL statements.  The series starts with this introductory article.

All the examples for this lesson are based on Microsoft SQL Server Management Studio and the AdventureWorks2012 database.  You can get started using these free tools using my Guide Getting Started Using SQL Server.

Understanding your Database Table’s Meanings and their Relationships to One Another

Understanding your database is more than just knowing it is built with tables, views, and relationships.  In order to write meaningful queries you need to understand how real world data was decoded and stored in the database.

These major components provide clues we can use to translate real-world requests into actionable database queries.  From understanding what content is contained within a table to understanding how to relate one table to another, knowing the database’s basic structure is key to creating queries. [click to continue…]

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circlepattern

This is the introductory article in a series explaining the three simple steps I take to writing complex SQL statements.

All the examples for this lesson are based on Microsoft SQL Server Management Studio and the AdventureWorks2012 database.  You can get started using these free tools using my Guide Getting Started Using SQL Server.

Introduction to Three Simple Steps to Writing SQL

Writing queries is difficult!  It’s hard enough sometimes to ask another person a question and get the right answer; asking a very literal minded computer sometimes seems nearly impossible.  What we say and what we mean are sometimes entirely different things.

If you understand SQL syntax, but are having a hard time formulating your queries, this article is for you.  It can be frustrating knowing all the pieces of the puzzle, but not having the knowledge to complete the full picture.  I think that once you go through the steps in this article series, you will gain the confidence to write SQL queries. [click to continue…]

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What is a Data Dictionary?

Data Dictionary - Cards

What is a Data Dictionary?

In SQL Server the data dictionary is a set of database tables used to store information about a database’s definition.  The dictionary contains information about database objects such as tables, indexes, columns, datatypes, and views.

The data dictionary is used by SQL server to execute queries and is automatically updated whenever objects are added, removed, or changed within the database.

All the examples for this article are based on Microsoft SQL Server Management Studio and the AdventureWorks2012 database.  You can get started using these free tools using my Guide Getting Started Using SQL Server. [click to continue…]

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Early DBAs

I recently met Gianluca Sartori and had a chance to interview him about his experience being a DBA.  You’ll find his answers very insightful.  Gianluca has great advice for new comers and shares some great tools and resources.  I think you find this article a worthwhile read!

Do you have any advice for people that want to start a career as a DBA?  For instance, are certifications a must?

Certifications can be a positive or negative thing, depending on how seriously you take it. Some people cheat the test and simply memorize brain dumps that can be easily found around the web. It goes without saying that cheating won’t earn you any additional knowledge. [click to continue…]

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Is SQL a Valuable Skill?

SQL is a Valuable SKILL

Are you serious about learning SQL?  If so, then get started with free tools using my Guide Getting Started Using SQL Server.

Is SQL a Sought Out Skill?

If I was to say that SQL is not a sought out skill would you believe me?   It is possible to safely say databases are now taken for granted and so easy to administer and query, that specialized knowledge is no longer required?

The answer to both answers is a resounding “no.”

As you’ll see below, the result of many surveys conclude SQL skills remain in the top ten sought out IT skills. [click to continue…]

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