Embedded Files
What is SQL?
SQL stands for Structured Query Language
SQL lets you access and manipulate databases
SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standardization (ISO) in 1987
What Can SQL do?
SQL can execute queries against a database
SQL can retrieve data from a database
SQL can insert records in a database
SQL can update records in a database
SQL can delete records from a database
SQL can create new databases
SQL can create new tables in a database
SQL can create stored procedures in a database
SQL can create views in a database
SQL can set permissions on tables, procedures, and views
Database Tables
A database most often contains one or more tables. Each table is identified by a name (e.g. "Customers" or "Orders"). Tables contain records (rows) with data.
In this tutorial we will use the well-known Northwind sample database (included in MS Access and MS SQL Server).
Below is a selection from the "Customers" table:
Some of The Most Important SQL Commands
SELECT - extracts data from a database
UPDATE - updates data in a database
DELETE - deletes data from a database
INSERT INTO - inserts new data into a database
CREATE DATABASE - creates a new database
ALTER DATABASE - modifies a database
CREATE TABLE - creates a new table
ALTER TABLE - modifies a table
DROP TABLE - deletes a table
CREATE INDEX - creates an index (search key)
DROP INDEX - deletes an index
Keep in Mind That...
SQL keywords are NOT case sensitive: select is the same as SELECT
In this tutorial we will write all SQL keywords in upper-case.
Tutorials
Practices
Feeling Confident at SQL?
Try out this quiz to check your SQL skills
Try out this test to check your SQL understanding
Challenges
Irish-Name-Repo 1
Description
There is a website running at https://jupiter.challenges.picoctf.org/problem/39720/ Do you think you can log us in? Try to see if you can login!
Hint: There doesn't seem to be many ways to interact with this, I wonder if the users are kept in a database? Try to think about how does the website verify your login?
Videos
Google Sites
Report abuse