Merangkum data

SQL Menengah untuk Kueri dengan AI

Jasmin Ludolf

Senior Data Science Content Developer

Fungsi agregat

SUM()
AVG()
MIN()
MAX()

Berapa rata-rata jumlah suara per film?

Laporan dengan statistik ringkasan

Merangkum bidang

Fungsi agregat merangkum beberapa baris menjadi satu nilai

Memahami data secara keseluruhan atau kelompok

Prompt: Tampilkan total jumlah suara di seluruh film

SELECT SUM(num_votes) AS total_votes
FROM reviews;

|total_votes|
|-----------|
|419507814  |

Menghitung rata-rata bidang

Prompt: Berapa rata-rata jumlah suara per film?

SELECT AVG(num_votes) AS average_votes_per_film
FROM reviews;

|average_votes_per_film|
|----------------------|
|84441.991545893720    |

Membulatkan hasil

Prompt: Berapa rata-rata jumlah suara per film yang dibulatkan?

SELECT ROUND(AVG(num_votes)) AS avg_votes
FROM reviews;

|avg_votes|
|---------|
|84442    |

ROUND(AVG(num_votes), 1)

84442.0

ROUND(AVG(num_votes), 2)

84441.99

ROUND(AVG(num_votes), -2)

Membulatkan hasil

Prompt: ...dibulatkan ke satu desimal

SELECT ROUND(AVG(num_votes), 1) AS avg_votes
FROM reviews;

|avg_votes|
|---------|
|84442.0  |

Prompt: ...dibulatkan ke ratusan terdekat

SELECT ROUND(AVG(num_votes), -2) AS avg_votes
FROM reviews;

|avg_votes|
|---------|
|84400    |

Rata-rata terkelompok

Prompt: Tampilkan rata-rata anggaran per bahasa, diurutkan dari anggaran tertinggi

SELECT language, ROUND(AVG(budget)) AS average_budget
FROM films
GROUP BY language
ORDER BY average_budget DESC;

|language |average_budget|
|---------|--------------|
|Greek    |              |
|Kannada  |              |    
|Polish   |              |
|Korean   |2741550000    |
...

Minimum dan maksimum

Prompt: Tampilkan anggaran terendah dan tertinggi per negara, diurutkan secara alfabetis

SELECT country, 
       MIN(budget) AS lowest_budget, 
       MAX(budget) AS highest_budget
FROM films
GROUP BY country
ORDER BY country;

|country    |lowest_budget|highest_budget|
|-----------|-------------|--------------|
|Afghanistan|46000        |46000         |
|Argentina  |800000       |2000000       |
|Aruba      |35000000     |35000000      |
...

Identifikasi rentang
Pahami cakupan data
Pahami nilai tipikal

Fungsi agregat dan tipe data

Hanya bidang numerik

SUM()
AVG()

Berbagai tipe data

MIN()
MAX()
COUNT()

Minimum <-> Maksimum

Terendah <-> Tertinggi
A <-> Z
Terawal <-> Terbaru

Minimum dan maksimum

SELECT MIN(language) AS min_language
FROM films;

|min_language|
|------------|
|Aboriginal  |

SELECT MAX(language) AS max_language
FROM films;

|max_language|
|------------|
|Zulu        |

Praktik terbaik SQL: alias

SELECT SUM(budget) AS total_budget
...

SELECT AVG(budget) AS average_budget
...

SELECT country, 
       MIN(budget) AS lowest_budget, 
       MAX(budget) AS highest_budget
...

SELECT AVG(num_user), AVG(num_critic)
FROM reviews;

|avg     |avg     |
|275.6...|141.9...|

Praktik terbaik SQL: pemformatan

Tulis kueri dalam beberapa baris
Gunakan indentasi

SELECT country, 
       MIN(budget) AS lowest_budget, 
       MAX(budget) AS highest_budget
FROM films
GROUP BY country
ORDER BY country;

Kacamata di atas kertas

Ikon SQL

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SQL Menengah untuk Kueri dengan AI