Course Content

SQL Basics

1. Selecting

The very first meet with the database SELECTing certain columns LIMITing results Unique values from column Unique values from multiple columns How many?How many unique?Aliases Tables aliases

2. Filtering

Word filtering Number filtering Combining conditions Filtering by numeric interval Multiple filtering on one column LIKE filtering NOT like this!

3. Aggregating

MINimal and MAXimal values SUMming values Mean values ROUNDing

4. Sorting

Sorting by one column Sorting in DESCending order The cheapest car Sorting by multiple columns

5. Grouping

What is grouping?More aggregate statistics!Grouping by multiple columns The cheapest combination HAVING some conditions Least consuming cars Filtering group size

6. Practicing

Challenge: Unique combinations Challenge: Average Q-series cars price Challenge: The cheapest new A-series cars Challenge: Relation between engine size and fuel consumption Challenge: Mileage and manufacture year - is there relation?Challenge: Average price for each model and year Challenge: The most expensive transmission + engine size combinations

SELECTing certain columns

Let's dig into our database. This database has 9 columns:

model - model of the car
year - year of manufacture
price - car price in Euros
transmission - type of gearbox
mileage - miles drove
fueltype - engine fuel type
tax - road tax
mpg - miles per gallon
enginesize - engine size in liters.

To extract certain columns you need to select them by their names, like:


              12
            
SELECT column1, column2, column3
FROM table_name

Please note, that SQL is also case-insensitive to column names, i.e. if the column has name id both notations id and ID will be interpreted the same.

Task

Extract columns model, year, and price from the audi_cars database.

Task

Extract columns model, year, and price from the audi_cars database.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Section 1. Chapter 2

SELECTing certain columns

Let's dig into our database. This database has 9 columns:

model - model of the car
year - year of manufacture
price - car price in Euros
transmission - type of gearbox
mileage - miles drove
fueltype - engine fuel type
tax - road tax
mpg - miles per gallon
enginesize - engine size in liters.

To extract certain columns you need to select them by their names, like:


              12
            
SELECT column1, column2, column3
FROM table_name

Please note, that SQL is also case-insensitive to column names, i.e. if the column has name id both notations id and ID will be interpreted the same.

Task

Extract columns model, year, and price from the audi_cars database.

Task

Extract columns model, year, and price from the audi_cars database.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Section 1. Chapter 2

SELECTing certain columns

Let's dig into our database. This database has 9 columns:

model - model of the car
year - year of manufacture
price - car price in Euros
transmission - type of gearbox
mileage - miles drove
fueltype - engine fuel type
tax - road tax
mpg - miles per gallon
enginesize - engine size in liters.

To extract certain columns you need to select them by their names, like:


              12
            
SELECT column1, column2, column3
FROM table_name

Please note, that SQL is also case-insensitive to column names, i.e. if the column has name id both notations id and ID will be interpreted the same.

Task

Extract columns model, year, and price from the audi_cars database.

Task

Extract columns model, year, and price from the audi_cars database.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Let's dig into our database. This database has 9 columns:

model - model of the car
year - year of manufacture
price - car price in Euros
transmission - type of gearbox
mileage - miles drove
fueltype - engine fuel type
tax - road tax
mpg - miles per gallon
enginesize - engine size in liters.

To extract certain columns you need to select them by their names, like:


              12
            
SELECT column1, column2, column3
FROM table_name

Please note, that SQL is also case-insensitive to column names, i.e. if the column has name id both notations id and ID will be interpreted the same.

Task

Extract columns model, year, and price from the audi_cars database.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Section 1. Chapter 2

Switch to desktop for real-world practiceContinue from where you are using one of the options below