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Transact SQL (T-SQL) for Beginners (A New Hope)
- 1. Transact SQL (T-SQL) for Beginners (A New Hope) What is it and how can I use it? This is for people who are new to T-SQL. We are covering SELECT, FROM, WHERE, GROUP BY, HAVING, ORDER BY and How to do a Backup.
- 2. About Andrea: Once upon a time in a kingdom not far away, Andrea was sick of answering phones and filing forms. Her kingdom was running low on gold and the wise wizard told her to find work that she loved and she would never truly work a day in her life. When she found the magical SQL Server, she knew it was the calling for her. She is passionate about SQL Server, “works” as a Database Administrator, is learning Sign Language, loves her #SQLFamily and finds joy in helping others find their passion too. Wife to Ryan Allred and mom to two awesome teenagers. Loves Music, concerts, guitars, snowboarding, bouldering and acting. 16 years of SQL Server experience SQL SLC User group Chapter Leader Allred_andrea@yahoo.com @RoyalSQL, www.RoyalSQL.com
- 3. What is T-SQL? SQL is Structured Query Language Transact Structured Query Language Microsoft Standard PL-SQL is Oracle
- 4. Let’s Start at the Very Beginning SELECT – what I want FROM – where I get it WHERE – only if it matches what I want GROUP BY – summarize it for me HAVING – used after a group by to filter ORDER BY – sort it the way I want it
- 5. How is it like English? I buy milk from the store if it is chocolate. SELECT – I buy milk FROM – from the store WHERE – if it is chocolate. SELECT milk FROM store WHERE flavor = chocolate
- 6. SELECT- Use it Wisely SELECT * is a quick way to see all the fields. I like to use a SELECT TOP 5 when using * When writing code or reports, always list out the fields (SELECT DisplayName, Location, Reputation, UpVotes) Know what is being selecting from and how many rows to expect.
- 7. FROM – Show me the Data! FROM a table name (Users) Must also include the schema name (dbo.Users) Can connect multiple tables using joins, we will do that later. SELECT TOP 5 * FROM StackOverflow.dbo.Users
- 8. WHERE – Cutting out the data that you don’t need…one clause at a time. Bringing back too much data will hurt performance “WHERE” brings back only what you need Non-Mutants can only look at so much data and have it be useful.
- 9. Building a Where Clause Column, operator, what is being comparing against. WHERE DisplayName = ‘Anon’ I only want people that have the Display Name of Anon.
- 10. Basic Operators (Can it really be this simple?) = Equals – It’s all the same. WHERE DisplayName = 'Anon' <> or != Does Not Equal – Not a match. WHERE DisplayName != 'Anon' WHERE DisplayName <> 'Anon'
- 11. Basic Operators Continued > Greater Than – The column has more WHERE UpVotes > 23793 >= Greater Than or Equal to WHERE UpVotes >= 23793 < Less Than – The column has less WHERE UpVotes < 45 <= Less Than or Equal to WHERE UpVotes <= 45
- 12. When the Basics Won’t Do… Super Cool Operators LIKE – It’s like you know WHERE DisplayName LIKE 'Anon%' NOT LIKE – It’s not like that WHERE DisplayName NOT LIKE 'Anon%'
- 13. Super Cool Operators Continued IN – Is it in this? WHERE DisplayName IN ('Anon', 'Anonymous', 'Anonymoose') NOT IN – It’s soooo not in that. WHERE DisplayName IN ('Anon', 'Anonymous', 'Anonymoose')
- 14. Super Cool Operators Continued BETWEEN – Stuck in the middle WHERE UpVotes BETWEEN 5000 AND 5045 NOT BETWEEN – It’s outside of that. WHERE UpVotes NOT BETWEEN 5000 AND 5045
- 15. GROUP BY – Let’s Get Together Gathers similar Data together Used to create Aggregates Awesome for Totals, Averages and Counts GROUP BY Columns that you don’t want to Sum, Count or Average Can have multiple columns in GROUP BY GROUP BY [DisplayName],[Location]
- 16. Having – What do you Have? Works with a GROUP BY This is another way to filter out data. Can have multiple columns in HAVING Clause. HAVING COUNT(Id) > 50
- 17. ORDER BY – We Must Have Order This is how we can sort our data We can sort by more than one column Automatically assumes Ascending (ASC) Can change to Descending (DESC) Multiple columns can be in ORDER BY ASC and DESC can be done by column
- 18. Order of Operations FROM WHERE GROUP BY HAVING SELECT ORDER BY
- 19. Joins – Bringing the World Together
- 20. What kinds of Joins? INNER – only what matches in both LEFT JOIN – everything from the left table and what matches in right RIGHT JOIN – everything from the right table and what matches in the left. FULL JOIN – everything from both tables.
- 21. INNER JOIN – Its Picky Only brings back results that are in both tables. INNER JOIN, JOIN are all the same. Caution: you won’t see what is eliminated.
- 22. INNER JOIN FROM StackOverflow.dbo.Users U INNER JOIN StackOverflow.dbo.Badges B ON U.Id = B.UserId
- 23. LEFT JOIN – Soooo one sided Brings in all the rows from the table on the left and only what matches on the right. LEFT OUTER JOIN, LEFT JOIN You will see Nulls
- 24. LEFT JOIN FROM StackOverflow.dbo.Users U LEFT JOIN StackOverflow.dbo.Badges B ON U.Id = B.UserId
- 25. RIGHT JOIN – Always Look on the Right Side of Life Same as a LEFT JOIN, just switched. RIGHT OUTER JOIN, RIGHT JOIN You will see nulls in the left table
- 26. RIGHT JOIN FROM StackOverflow.dbo.Users U RIGHT JOIN StackOverflow.dbo.Badges B ON U.Id = B.UserId
- 27. FULL JOINS – Everything, Everything? Brings back everything in both tables. FULL OUTER JOIN, FULL JOIN You will see nulls on both sides of the tables
- 28. FULL JOINS FROM StackOverflow.dbo.Users U FULL JOIN StackOverflow.dbo.Badges B ON U.Id = B.UserId
- 29. Script out a Basic Backup BACKUP DATABASE TO DISK = N‘location’ WITH NOFORMAT NOINIT NAME = N‘’ SKIP NOREWIND NOUNLOAD STATS = 10
- 30. More Resources http://www.sqlcourse.com https://blog.codinghorror.com/a-visual- explanation-of-sql-joins/ https://docs.microsoft.com/en-us/sql/t-sql/statements/ba Check out my blog www.RoyalSQL.com If you have questions, contact me. Allred_andrea@yahoo.com
Editor's Notes
- T-SQL is a lot like a spoken language and once you flip the switch in your brain it will be simple. When I was first learning T-SQL, I started to Dream in it and I ended up cleaning my entire house using T-SQL. I woke up exhausted and sad to find out that my house wasn’t clean.
- D
- Demo – Only one
- Demo Everything has it’s opposite.
- Super cool operators will affect performance. They are not the best to use if you can avoid it.
- Super cool operators will affect performance. They are not the best to use if you can avoid it.
- Demo Super cool operators will affect performance. They are not the best to use if you can avoid it.
- Demo
- Demo
- Demo
- Demo
- BACKUP DATABASE [StackOverflow] TO DISK = N&apos;C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\Backup\StackOverflow.bak&apos; WITH NOFORMAT, NOINIT, NAME = N&apos;StackOverflow-Full Database Backup&apos;, SKIP, NOREWIND, NOUNLOAD, STATS = 10 BACKUP DATABASE (Name) TO DISK = N‘location’ (Location) WITH NOFORMAT (Uses the existing media header and backup set FORMAT will create new ones.) NOINIT (Appends to existing backup set INIT means Overwrite) NAME = N‘’ (What you want to name it) SKIP (Doesn’t check the expiration date before overwriting – NOSKIP will check) NOREWIND (Means it will keep the tape open after backup, REWIND means SQL will release and rewind the tape) NOUNLOAD (Means the tape will stay loaded in the tape drive, UnLoad means the tape is rewound and unloaded. When the backup finishes) STATS = 10 – Displays a percentage after each section is complete. The default is 10.
- T-SQL Demos: /*Basic SELECT and FROM*/ SELECT TOP 5 * FROM [StackOverflow].[dbo].[Users] /* Specified Columns SELECT and FROM*/ SELECT TOP (10) [DisplayName] ,[Location] ,[Reputation] ,[UpVotes] FROM [StackOverflow].[dbo].[Users] ******** /* WHERE = */ SELECT TOP (10) [DisplayName] ,[Location] ,[Reputation] ,[UpVotes] FROM [StackOverflow].[dbo].[Users] WHERE DisplayName = &apos;Anon&apos; --********** /* WHERE != &lt;&gt;*/ SELECT TOP (10) [DisplayName] ,[Location] ,[Reputation] ,[UpVotes] FROM [StackOverflow].[dbo].[Users] WHERE DisplayName != &apos;Anon&apos; /* WHERE &gt; &gt;= */ SELECT [DisplayName] ,[Location] ,[Reputation] ,[UpVotes] FROM [StackOverflow].[dbo].[Users] WHERE UpVotes &gt;= 23793 /* WHERE &gt; &gt;= */ SELECT TOP 10 [DisplayName] ,[Location] ,[Reputation] ,[UpVotes] FROM [StackOverflow].[dbo].[Users] WHERE UpVotes &lt; 45 --********* /*WHERE LIKE NOT LIKE */ SELECT TOP 10 [DisplayName] ,[Location] ,[Reputation] ,[UpVotes] FROM [StackOverflow].[dbo].[Users] WHERE DisplayName LIKE &apos;Anon%&apos; /*WHERE IN NOT IN */ SELECT TOP 10 [DisplayName] ,[Location] ,[Reputation] ,[UpVotes] FROM [StackOverflow].[dbo].[Users] WHERE DisplayName IN (&apos;Anon&apos;, &apos;Anonymous&apos;, &apos;Anonymoose&apos;) /* WHERE BETWEEN NOT BETWEEN */ SELECT TOP 15 [DisplayName] ,[Location] ,[Reputation] ,[UpVotes] FROM [StackOverflow].[dbo].[Users] WHERE UpVotes BETWEEN 5000 AND 5045 --*********** /* GROUP BY COUNT AVG SUM MIN MAX*/ SELECT [DisplayName] ,[Location] ,COUNT([UpVotes]) ,COUNT(Id) FROM [StackOverflow].[dbo].[Users] WHERE DisplayName = &apos;Anon&apos; GROUP BY DisplayName, [Location] --********************* /*HAVING */ SELECT [DisplayName] ,[Location] ,SUM([UpVotes]) AS UpVotes ,COUNT(Id) FROM [StackOverflow].[dbo].[Users] WHERE DisplayName = &apos;Anon&apos; GROUP BY DisplayName, [Location] HAVING SUM([UpVotes]) &gt; 5 --************* /*ORDER BY ASC DESC*/ SELECT [DisplayName] ,[Location] ,SUM([UpVotes]) AS UpVotes ,COUNT(Id) AS Count FROM [StackOverflow].[dbo].[Users] WHERE DisplayName = &apos;Anon&apos; GROUP BY DisplayName, [Location] HAVING SUM([UpVotes]) &gt; 5 ORDER BY Count --*********** /*INNER JOIN*/ SELECT TOP 5 U.Id, U.DisplayName, U.Location, U.Reputation, U.UpVotes,B.Name FROM StackOverflow.dbo.Users U INNER JOIN StackOverflow.dbo.Badges B ON U.Id = B.UserId WHERE DisplayName = &apos;Anon&apos; /*LEFT JOIN*/ SELECT U.*, B.*--U.Id, U.DisplayName, U.Location, U.Reputation, U.UpVotes,B.Name FROM StackOverflow.dbo.Users U LEFT JOIN StackOverflow.dbo.Badges B ON U.Id = B.UserId WHERE DisplayName = &apos;Anon&apos; AND U.Id = 3903518 /*RIGHT JOIN*/ SELECT U.Id, U.DisplayName, U.Location, U.Reputation, U.UpVotes,B.Name FROM StackOverflow.dbo.Users U RIGHT JOIN StackOverflow.dbo.Badges B ON U.Id = B.UserId WHERE B.UserId = 2253640 /*FULL JOIN*/ SELECT U.Id, U.DisplayName, U.Location, U.Reputation, U.UpVotes,B.Name FROM StackOverflow.dbo.Users U FULL JOIN StackOverflow.dbo.Badges B ON U.Id = B.UserId WHERE B.UserId = 2253640 OR U.Id = 3903518 --*********