SQL: Read a Database like an Expert
- 2 hours on-demand video
- 1 article
- 17 downloadable resources
- Full lifetime access
- Access on mobile and TV
- Certificate of Completion
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- Learn about an unfamiliar database quickly
- Construct a physical data model
- Recognise the role of each table
- Recognise clusters or groups of tables
- Recognise how business processes interact with the tables
- You should recognise a basic SQL SELECT statement
- You will need a suitable Windows system if you are going to install SQL Server and do the exercises yourself.
What would you do if you were presented with an unfamiliar database and no documentation?
When you have completed this course you will be able to answer this question. You will have a plan, a method and several techniques you can use. This course is for:
- Aspiring System or Database Designers
You will learn how to find your way around a database quickly and efficiently. You can become the “go to” person in your specialisation simply by being able to “read a database like a book”. You become the person with the map, or the book of instructions!
- If you are an analyst this course will enable you to write better queries more quickly, and you will learn how the database influences what the system can do.
- If you are moving into database design, learning to “read” will allow you to use existing databases as a resource which you can understand, criticise and copy.
- As a developer this course shows you how to use the database as documentation for the system it supports.
I wrote this course as an extended tutorial. I started with one of Microsoft’s example databases and documented the method I use as I went through it. Although I used SQL Server and the associated tools, the method is applicable to most SQL databases. We will go through the same journey together and you will learn what I discovered along the way. You can choose to repeat what I do yourself to gain experience with the technique, or you can choose simply to observe.
Come along! Sign up! There are some surprises and a lot of fun to be had!
- This course is for people who know a little SQL and want to explore more complex databases.
- This course is probably not for you if you are looking to write advanced SQL queries.
When you have completed this lecture you will know:
- That the objective of this course is for you to “Read an SQL Database like a book” using the DOGI method.
- What a physical data model looks like
- How the course is structured
- All you need to start is that you understand the basic SELECT statement.
When you have completed this lecture you will know a little more about me, my background and why I am qualified to teach this course.
This lecture introduces the DOGI method which we will use through the rest of the course.
- D = Diagram
- O = Organise
- G = Group
- I = Individual
When you have completed this lecture you will have seen how to create a physical database diagram using SSMS (SQL Server Management Studio).
This lecture provides an overview of this section.
- It reviews the groups or clusters we identified on the diagram
- Describes the way we are going to tackle them
- Suggests alternative strategies.
- You will understand what the Header and Detail tables are doing, and
- You will understand why this is important
- You have seen that there are additional relationships between Sales Order Header and Address
In this lecture well look at the Customer Address group in much more detail. When you have completed this lecture:
- You will know how to use the DISTINCT keyword to identify the possible values of a Type or Status column.
- You will know how the actual values used relates to common practice in the business world
- You will have gained insight into the designer’s intentions for the database and the processing around “Taking an Order”
- Finally, you will be equipped to criticise a possible defect in the design of this database
In this lecture we'll look inside the tables Sales Order Header and Sales Order Detail. When you have completed this lecture:
- You will have learned about the use of Status columns
- You will have seen me attempt to use the DISTINCT keyword again. This time it won’t be so productive.
- You will have learned that there are sometimes “date” columns associated with status
- Finally, you have seen that in this case the allowable status values are documented in the column description.
In this lecture we will look in detail at the Product table. When you have completed this lecture, you will have learned that:
- A sequence of dates can be used to define various “states”, even when there is no status column
- This arrangement can be used to define changes in advance
- This is a common way of handling seasonal products and similar situations
- In this lecture we will look inside the Product Category table.
- You will learn one way categories are represented in data.
- You will learn how to use simple queries to explore such a hierarchy.
- You will see how the hierarchy in this database can be presented.
- In this lecture we will look inside the Product Description Group of tables.
- You will learn another way of tables being used together.
- This time you will see a case where several different values are valid at the same time.
- In this case this structure is being used to provide support for several languages
When you have completes this lecture you will have:
- Seen State Transition Diagrams constructed in practise. In this case for:
- Sales Order
- Seen those State Transition Diagrams used to identify processes
- Seen those State Transition Diagrams related to Use Cases