Join Bill Weinman for an in-depth discussion in this video Creating an ID column, part of SQL Essential Training.
…ID columns are columns that hold a unique value for each row in a table.…Typically, ID columns are automatically populated.…The method for creating an ID column, is not standardized.…How you create an ID column is different for every database system.…I'm going to show you how this works…in SQLite, the database system we're using here.…Keep in mind that this will be different for other database systems.…I'm showing you this just so you'll have an idea how it…works, but know that the specific syntax will be different on different systems.…
So here I'm using the in-memory database and we'll start by creating a table.…Now this first column is the ID column.…So I'm going to name it ID, you can name it whatever you like.…ID is pretty common, and it'll be an integer.…And for SQLite and most database systems the ID column…has to be of an integer type of some sort.…And in SQLite if you use the key words primary key,…and this is where the constraint goes in the syntax.…
This will automatically generate ID's in SQLite.…
- Understanding SQL terminology and syntax
- Creating new tables and records
- Inserting and updating data
- Writing basic SQL queries
- Sorting and filtering
- Accessing related tables with JOIN
- Working with strings
- Finding the numeric type of a value
- Using aggregate functions and transactions
- Updating a table with triggers
- Creating views
Skill Level Beginner
Q: For Mac OS X: When I try to start the Apache Web Server from the XAMPP control panel, it doesn't start, and when I open "localhost" in my web browser, I see a white screen that says "It Works!" instead of the XAMPP page.
sudo apachectl stop
Q: I'm on a Mac, and I get an error in SID that says "attempt to write a read only database." How can I fix this?
A: This usually means that the database folder does not have sufficient permissions for writing by the web user. This can happen if you create the SQL folder new, rather than copying it from the Exercise Files. Here's how to fix this:
- Open a Finder window and Navigate to /Applications/XAMPP/htdocs/SQL
- Control-click on the SQL folder and select "Get Info" from the context menu.
- Under "Sharing and Permissions" (you may need to open the disclosure triangle), in the "everyone" row, select "Read & Write."Then you can close the Info window.
- Now repeat the process for the three *.db files inside the folder.
1. SQL Quick Start
Understanding joins2m 23s
Dates and times1m 59s
10. Subselects and Views
11. A Simple CRUD Application
- Mark as unwatched
- Mark all as unwatched
Are you sure you want to mark all the videos in this course as unwatched?
This will not affect your course history, your reports, or your certificates of completion for this course.Cancel
Take notes with your new membership!
Type in the entry box, then click Enter to save your note.
1:30Press on any video thumbnail to jump immediately to the timecode shown.
Notes are saved with you account but can also be exported as plain text, MS Word, PDF, Google Doc, or Evernote.