Skip to main content

SQL Journey: Blog #12



What's up Nixers! After finishing the Power BI tutorial by Alex the Analyst, I decided to embark on learning SQL once again. A sort of a review of what I have already learned in Khan Academy. I am already in 5 of the 17 videos in this playlist.


The reason why I decided on this next step is to test my knowledge of SQL following what I have learned in Khan Academy. I thought to myself that if I can use my SQL skills to do what he instructs before looking at the code he uses, then I will have better confidence moving forward. If not, I will have a serious look at what I lack and improve on those things.

The things that I noticed is that Alex uses SQL Server Management Studio (SSMS) while Khan Academy uses SQLlite.js. I learned the difference the hard way as I committed errors in the codes that I used. In SQLlite, the use of 'TEXT' as a data type was now changed to 'varchar(size)'  is prevalently used in SQLServer. Also, when assigning values, the use of single-quotation marks when the data type is varchar is also prevalent. Like, a syntax error will result if the double quotation marks is used.

Alex also explained INNER JOIN, LEFT OUTER JOIN, RIGHT OUTER JOIN, and FULL OUTER JOIN more clearly. Here's what I learned big time. Whenever "JOIN" is used, there must ALWAYS be an "ON" statement. I don't know if this is just a small thing but for me this is a big deal considering I sometimes forget the syntax so having this mnemonic or understanding would go a long way.

I also do not use copy and paste of codes. I type codes manually for me to familiarize my self with the syntaxes. Another thing that I made sure to find a way about is how to show the "line" relating to a code, so that I can easily trace the error when it prompts. Next, I used SQLShades to activate DARK mode when coding. It is more eye-friendly and fit for my preference since I also use dark mode in Pycharm.

Whew! 12 more lessons to go. 

Comments

Popular posts from this blog

Privacy Policy of ShinStats: descriptives calc

Privacy Policy Shin Nix built the ShinStats app as an Ad Supported app. This SERVICE is provided by Shin Nix at no cost and is intended for use as is. This page is used to inform visitors regarding my policies with the collection, use, and disclosure of Personal Information if anyone decided to use my Service. If you choose to use my Service, then you agree to the collection and use of information in relation to this policy. The Personal Information that I collect is used for providing and improving the Service. I will not use or share your information with anyone except as described in this Privacy Policy. The terms used in this Privacy Policy have the same meanings as in our Terms and Conditions, which are accessible at ShinStats unless otherwise defined in this Privacy Policy. Information Collection and Use For a better experience, while using our Service, I may require you to provide us with certain personally identifiable information. The information that I request will be retaine...

Power BI Journey: Blog #6

In this lesson, the focus is on "Conditional Formatting" which is very much similar to the conditional formatting in MS Excel which I could relate to following the making of the joint reporting system for personnel during my second job. Basically, we click the data columns that we want to be displayed in a tabular visualization.  Next, we select the columns that we will be applying conditional formatting to > Right-click on that column > Select Conditional Formatting > Select from among the options which is more appropriate for your application In this particular exercise, we utilized Background conditional formatting using gradient (applied on the first column of the first table) and rules (IF ELSE which was applied on the second column of the first table), Icons conditional formatting (applied on the second column of the first table), Data bars conditional formatting (applied on the second column of the first table and the fourth column of the second table). In the...

SQL Journey: Blog#10

So far, we are only "reading" from a given database or table using the SELECT command of SQL. In today's lesson, we will now start "writing" into a given database using the UPDATE and DELETE commands. Challenge: Dynamic Documents Given data: CREATE table documents (     id INTEGER PRIMARY KEY AUTOINCREMENT,     title TEXT,     content TEXT,     author TEXT);      INSERT INTO documents (author, title, content)     VALUES ("Puff T.M. Dragon", "Fancy Stuff", "Ceiling wax, dragon wings, etc."); INSERT INTO documents (author, title, content)     VALUES ("Puff T.M. Dragon", "Living Things", "They're located in the left ear, you know."); INSERT INTO documents (author, title, content)     VALUES ("Jackie Paper", "Pirate Recipes", "Cherry pie, apple pie, blueberry pie."); INSERT INTO documents (author, title, content)     VALUES ("Jackie Paper", "Boat Supplies...