Berikut perintah-perintah QUERY pada MYSQL
1. Seleksi Data dengan perintah SELECT
Untuk melakukan seleksi data-data yang ada pada table mysql dipergunakan perintah SELECT. Sebelum menggunakan perintah SELECT akan dibuat terlebih dahulu table berikut data-data yang ada didalamnya:
mysql> CREATE TABLE pet (name VARCHAR(20), owner VARCHAR(20),species VARCHAR(20), sex CHAR(1), birth DATE, death DATE);
Melakukan penyisipan data pada table pet
mysql >INSERT INTO pet(name,owner,species,sex,birth,death) values('Fluffy','Harold','cat','f','1993-02-04','');
mysql> INSERT INTO pet(name,owner,species,sex,birth,death) values('Claws','Gwen','cat',' m','1994-03-17','');
mysql >INSERT INTO pet(name,owner,species,sex,birth,death) values('Buffy',' Harold','dog','f','1989-05-13','');
Masukkan data lain sehingga data pada table pet
name
|
owner
|
species
|
sex
|
birth
|
death
|
Fluffy
|
Harold
|
cat
|
f
|
04/02/1993
| |
Claws
|
Gwen
|
cat
|
m
|
17/03/1994
| |
Buffy
|
Harold
|
dog
|
f
|
13/05/1989
| |
Fang
|
Benny
|
dog
|
m
|
27/08/1990
| |
Bowser
|
Diane
|
dog
|
m
|
31/08/1979
|
29/07/1995
|
Chirpy
|
Gwen
|
bird
|
f
|
11/09/1998
| |
Whistler
|
Gwen
|
bird
|
09/12/1997
| ||
Slim
|
Benny
|
snake
|
m
|
29/04/1996
|
• Seleksi semua data yang ada pada table pet:
mysql > select * from pet;
• Seleksi baris tertentu
• mysql> SELECT * FROM pet WHERE name = 'Bowser';
• mysql> SELECT * FROM pet WHERE birth >= '1998-1-1';
• mysql> SELECT * FROM pet WHERE species = 'dog' AND sex = 'f';
• mysql> SELECT * FROM pet WHERE species = 'snake' OR species = 'bird';
• mysql> SELECT * FROM pet WHERE (species = 'cat' AND sex = 'm') OR (species = 'dog' AND sex = 'f');
• Seleksi kolom tertentu
mysql> SELECT name, birth FROM pet;
• Seleksi nama pemilik pet
mysql> SELECT owner FROM pet;
• Seleksi nama pemilik pet tetapi nama sama ditampilkan satu kali
mysql> SELECT DISTINCT owner FROM pet;
• Seleksi data yang tergolong cat atau dog
mysql> SELECT name, species, birth FROM pet WHERE species = 'dog' OR species = 'cat';
2. Sorting baris pada tabel
Seleksi data diurutkan berdasarkan tanggal lahir
mysql> SELECT name, birth FROM pet ORDER BY birth;
Seleksi data diurutkan berdasarkan tanggal lahir diurutkan secara terbalik
mysql> SELECT name, birth FROM pet ORDER BY birth DESC;
Pengurutan data berdasarkan beberapa kolom data :
mysql> SELECT name, species, birth FROM pet ORDER BY species, birth DESC;
3. Kalkulasi usia
mysql> SELECT name, birth, CURDATE(),(YEAR(CURDATE())-YEAR(birth))-(RIGHT(CURDATE(),5)<RIGHT(birth,5)) AS age FROM pet;
Kalkulasi usia diurutkan berdasarkan nama:
SELECT name, birth, CURDATE(),(YEAR(CURDATE())-YEAR(birth))-(RIGHT(CURDATE(),5)<RIGHT(birth,5)) AS age FROM pet ORDER BY name;
Kalkulasi usia diurutkan berdasarkan usia
mysql> SELECT name, birth, CURDATE(),(YEAR(CURDATE())-YEAR(birth))-(RIGHT(CURDATE(),5)<RIGHT(birth,5)) AS age FROM pet ORDER BY age;
SELECT name, birth, death,(YEAR(death)-YEAR(birth)) - (RIGHT(death,5)<RIGHT(birth,5)) AS age FROM pet WHERE death IS NOT NULL ORDER BY age;
mysql> SELECT name, birth, MONTH(birth) FROM pet;
SELECT name, birth FROM pet WHERE MONTH(birth) = 5;
4. Pattern Matching
Digunakan untuk melakukan seleksi berdasarkan pola tertentu
mysql> SELECT * FROM pet WHERE name LIKE 'b%';
Perintah tersebut digunakan untuk mencari data yang name diawali huruf b.
mysql> SELECT * FROM pet WHERE name LIKE '%fy';
Digunakan untuk mencari data name yang mengandung fy
mysql> SELECT * FROM pet WHERE name LIKE '%w%';
Selain menggunakan LIKE Pattern Matching dapat menggunakan REGEXP
mysql> SELECT * FROM pet WHERE name REGEXP '^b';
mysql> SELECT * FROM pet WHERE name REGEXP 'fy$';
mysql> SELECT * FROM pet WHERE name REGEXP 'w';
5. Menghitung jumlah baris
Untuk menghitung baris dipergunakan operator COUNT.
mysql> SELECT COUNT(*) FROM pet;
mysql> SELECT owner, COUNT(*) FROM pet GROUP BY owner;
mysql> SELECT species, sex, COUNT(*) FROM pet WHERE species = 'dog' OR species = 'cat' GROUP BY species, sex;
mysql> SELECT species, sex, COUNT(*) FROM pet WHERE sex IS NOT NULL GROUP BY species, sex;
