Filtering numbers

SQL - Livello Intermedio

Jasmin Ludolf

Data Science Content Developer, DataCamp

WHERE

WHERE filtering clause

Image showing a variety of colorful coats

WHERE

WHERE color = 'green'

Image showing a variety of colorful coats and with a circle around the green coat

WHERE with comparison operators

SELECT title
FROM films
WHERE release_year > 1960;

|title                |
|---------------------|
|Judgment at Nuremberg|
|Pocketful of Miracles|
|The Hustler          |
|The Misfits          |
...

Comparison operators

SELECT title
FROM films
WHERE release_year < 1960;

|title                                          |
|-----------------------------------------------|
|Intolerance:Love's Struggle Throughout the Ages|
|Over the Hill to the Poorhouse                 |
|The Big Parade                                 |
|Metropolis                                     |
...

Comparison operators

SELECT title
FROM films
WHERE release_year <= 1960;

|title                                          |
|-----------------------------------------------|
|Intolerance:Love's Struggle Throughout the Ages|
|Over the Hill to the Poorhouse                 |
|The Big Parade                                 |
|Metropolis                                     |
...

Comparison operators

SELECT title
FROM films
WHERE release_year = 1960;

|title        |
|-------------|
|Elmer Gantry |
|Psycho       |
|The Apartment|

Comparison operators

SELECT title
FROM films
WHERE release_year <> 1960;

|title                                          |
|-----------------------------------------------|
|Intolerance:Love's Struggle Throughout the Ages|
|Over the Hill to the Poorhouse                 |
|The Big Parade                                 |
|Metropolis                                     |
...

Comparison operators

> Greater than or after
< Less than or before
= Equal to
>= Greater than or equal to
<= Less than or equal to
<> Not equal to

WHERE with strings

Use single-quotes around strings we want to filter

SELECT title
FROM films
WHERE country = 'Japan';

|title            |
|-----------------|
|Seven Samurai    |
|Tora! Tora! Tora!|
|Akira            |
|Madadayo         |
|Street Fighter   |
...

Order of execution

-- Written code:
SELECT item
FROM coats
WHERE color = 'green'
LIMIT 5;

Order of execution:

```
FROM coats
```
```
WHERE color = 'green'
```
```
SELECT item
```
```
LIMIT 5;
```

Let's practice!

SQL - Livello Intermedio