Database Fundamentals #14: Modifying Data Through SSMS

Database Fundamentals
I've said it before, but I feel I should repeat myself. Using the SSMS GUI for data entry and data manipulation is not the preferred mechanism. T-SQL is the right way to manipulate the data in your database. For purposes of completion though, I will show the GUI methods in this blog series. Information doesn’t go into the database and stay there, unchanged, forever. Data is modified. This occurs because information changes, such as when a person marries and changes their name, or information was incorrectly entered, in which case you need to fix it, or just about anything else. You have to have a mechanism for modifying existing information. Modifying Data You start modifying data in the tables the same way you did the insert, by taking advantage of…
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Database Fundamentals #13: Data Entry Through T-SQL

Database Fundamentals
T-SQL provides lots of functions that help to make data entry through T-SQL much more powerful. Over time you won’t be typing everything into T-SQL directly as we’ll do here. You’ll be able to use stored procedures and parameters to automate the use of scripts. These will also be generated or used by applications. To  start using T-SQL, you need to open a query window. You can do this by right clicking on a database and selecting the “New Query” command from the context menu. This will open a new query window in the main window on your screen. This is basically just a big, open text box into which you can type commands. The INSERT Statement To add rows using T-SQL, the principal statement is the INSERT statement. The…
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Database Fundamentals #12: Adding Data with SSMS GUI

Database Fundamentals
In the previous Database Fundamentals, I argued that you should be learning T-SQL, yet the very next post I'm showing you how to use the GUI. What's up? Why the GUI? It's a very simple reason. I want to show you what it is so that I'm not hiding things. However, showing it to you will quickly expose the weaknesses inherent in using the SSMS GUI for direct data manipulation. It's a poor choice. However, we'll understand how it works at the end of this post. I'll also cover it in other posts, showing how to UPDATE and DELETE data using the GUI. They will further illustrate the weaknesses. You will however know how it works. Data Entry through the GUI If you are not already connected to the server,…
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Database Fundamentals #11: Why Learn T-SQL

Database Fundamentals
If you've been following along with the previous 10 Database Fundamentals blog posts, you have a SQL Server installed and a database with a table in it. You may have more if you've been practicing. Now would be the time to start adding data to the database, but first, I want to talk about the importance of T-SQL Why T-SQL? The way SQL Server accepts information is very different than most programs you’re used to using. Most programs focus on the graphical user interface as a mechanism for enabling data entry. While there is a GUI within SQL Server that you can use for data entry, and I will do a blog post on it, the primary means of manipulating data within SQL is the Transact Structured Query Language, or…
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Database Fundamentals #10: Modifying Tables

Database Fundamentals
Invariably, either while building a new database, or while maintaining old ones, you will find that the business needs change or that you’ve made a mistake. Either way, you will need to modify the tables that you’ve created. Change is inevitable and luckily SQL Server takes that into account, providing you with mechanisms to modify structures after you’ve created them. Important Warning One of the fundamental concepts of databases is that the data is stored. You can’t simply throw data away when you need to make a change to a table. There are two levels of changes you can make to a table. The first, is a change that won’t affect data in the table. These are simple changes and we’ll cover them in this blog post. The second level…
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Database Fundamentals #9: Schemas As Containers

Database Fundamentals
Schemas are a very useful tool for managing the objects in your database. From security through process, through placement, schemas provide you with another tool to control how your database behaves. Schemas The tables created so far in this blog series have all been attached to a schema, dbo. Depending on how you login to the server and the security settings for your user, this is usually the default schema. A schema is simply a container in which you place objects. Once placed there, a schema is a method for managing the objects it contains. Schemas give you a simple way to control placement of the objects on filegroups. Schemas are a very easy way to manage security. The use of schemas becomes extremely important as your database becomes more…
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Luck and the PASS Summit

PASS
I recently read an article asking the question whether or not we downplay the role that luck plays in our lives and I immediately thought of the PASS Summit. Obscenely Lucky I am, quite frankly, embarrassingly, obscenely, stupidly lucky. I just am. I married WAY over my head. I stumbled into an amazing career. I can safely say that I've arrived where I am through a great amount of luck. I am quite grateful for it all too. I will only suggest a single point of agency on my part that has put me in this wonderful situation. I showed up. PASS Summit 2005 I went to the PASS Summit in 2005 in Grapevine. Mostly, I attended sessions and then went back to my hotel. However, one night, after talking…
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Database Fundamentals #8: All About Data Types

Database Fundamentals
SQL Server provides all different kinds of data types in order to give you more flexibility and control for how you store your data. You define these data types as you define the columns in your tables. If you wanted to store information about the date and time that a purchase was made online you’re going to store the values in a column, or columns, that define dates and times in order to ensure accuracy in your data. Choosing a Data Type You could make the data type into one that stores just about anything you give it, such as one of the character types like char or varchar. Do this and you’re going to run into issues when you start running queries against that data. For example, your business…
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Runtime Metrics In Execution Plans

SQL Server 2016
Capturing query execution metrics is much easier now that you can see the runtime metrics in execution plans when you're using SQL Server 2016 SP1 or better in combination with SQL Server Management Studio 2017. When you capture an actual plan (using any method), you get the query execution time on the server as well as wait statistics and I/O for the query. Fundamentally, this changes how we can go about query tuning. Runtime Metrics To see these runtime metrics in action, let's start with a query: SELECT p.LastName, pp.PhoneNumber, pnt.Name FROM Person.Person AS p JOIN Person.PersonPhone AS pp ON pp.BusinessEntityID = p.BusinessEntityID JOIN Person.PhoneNumberType AS pnt ON pnt.PhoneNumberTypeID = pp.PhoneNumberTypeID WHERE pnt.PhoneNumberTypeID = 3; We'll run this query and capture the Actual Execution Plan using SSMS 2017. The changes…
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Bad Parameter Sniffing Decision Flow Chart

SQL Server 2005, SQL Server 2008, SQL Server 2012, SQL Server 2014, SQL Server 2016
Lots of people are confused by how to deal with bad parameter sniffing when it occurs. In an effort to help with this, I'm going to try to make a decision flow chart to walk you through the process. This is a rough, quite rough, first draft. I would love to hear any input. For this draft, I won't address the things I think I've left out. I want to see what you think of the decision flow and what you think might need to be included. Click on it to embiggen. Thanks to the attendees at my SQLSaturday Louisville pre-con for the great questions and the inspiration to get this done. Thank you in advance for any and all feedback.
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