Some tips on how to query or using mysql, and some mysql feature / best practice

1. PHP Malang UG Meet Up, Nopember 2015
by Daud Mukadar
@dmukadar
Tips & Trik MySQL

2. $ whoami
• SLUG-er
• KLAS-er
• MPUG-er
• Accidental linux user
• Once an employee
• Freelance consultant
Daud Mukadar
• Been using PHP when GLOBAL VARIABLE
was the thing
• Love to solve problems
• Like to write queries
• Like to learn new things
• Currently bootstraping: Tunas Mandiri IT
Solution

3. • Other Trick
– Understanding join
– Partitioning
– Tree structure
• Prepare Data
• Simple tips
– forgot password
– Que on FK
– Serial as PK
– On Select
– HEAP!
On Menu Tonight

4. • Mockaroo.com
• GenerateData.com
• DummyData.me
• DatabaseTestData.com
Prepare Data

5. • Stop MySQL
$ sudo service mysqld stop #or sudo /etc/init.d/mysqld stop
• Re-run it without ACL functionality
$ sudo mysqld_safe ­­skip­grant­tables
• Hack a new password
$ mysql ­u root
mysql> use mysql;
mysql> update user set password = PASSWORD('obladi') where user =
'root'
• Flush it
mysql> flush privileges;
• Restart
$ sudo kill `pidof mysqld_safe`
$ sudo service mysql start
ST: What's the password dude?

6. • Should you use it?
• joining int with int
959 rows in set (0.10 sec)
• Joining int with tiny int
119 rows in set (0.03 sec)
• Joining int with unsigned int
959 rows in set (0.05 sec)
• Joining int with varchar
959 rows in set (0.06 sec)
• Joining varchar with varchar
Empty set (1.11 sec)
ST: on Foreign Key

7. • Using serial
mysql> CREATE TABLE tbl_users (
id SERIAL,
username VARCHAR(40) UNIQUE,
passwd VARCHAR(32) NOT NULL,
last_login TIMESTAMP NOT NULL,
last_ip_address INT(11) UNSIGNED,
created TIMESTAMP,
created_by INT(11),
updated TIMESTAMP,
updated_by INT(11)
) engine=InnoDB;
• Result
mysql> desc tbl_users;
• +­­­­­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­+­­­­­­+­­­­­+­­­­­­­­­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
• | Field | Type | Null | Key | Default | Extra |
• +­­­­­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­+­­­­­­+­­­­­+­­­­­­­­­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
• | id | bigint(20) unsigned | NO | PRI | NULL | auto_increment |
• | username | varchar(40) | YES | UNI | NULL | |
• | passwd | varchar(32) | NO | | NULL | |
• | last_login | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
• | last_ip_address | int(11) unsigned | YES | | NULL | |
• | created | timestamp | NO | | 0000­00­00 00:00:00 | |
• | created_by | int(11) | YES | | NULL | |
• | updated | timestamp | NO | | 0000­00­00 00:00:00 | |
• | updated_by | int(11) | YES | | NULL | |
• +­­­­­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­+­­­­­­+­­­­­+­­­­­­­­­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
• 9 rows in set (0.03 sec)
•
ST: Primary Key

8. • Asterisk or Not
mysql> select * from tbl_nilai where id_mhs = 958;
+­­­­­­+­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­+­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
| id | id_mhs | mata_kuliah | semester | nilai | updated | guid |
+­­­­­­+­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­+­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
| 464 | 958 | Ilmu ekonomi | 3 | 94.78 | 2015­10­01 | 7f5aeb02­ca5d­41d4­a513­51fe11c5bea6 |
| 529 | 958 | Fraud Examination | 8 | 57.75 | 2015­10­26 | 4fc65837­bd75­424b­9f68­b04903960f1e |
| 1113 | 958 | Matematika Ekonomi | 3 | 70.39 | 2015­10­04 | 00be5fdc­c28b­4c0a­9bf0­c3d39b2984f9 |
| 1672 | 958 | Ekonomi 2 | 4 | 66.49 | 2015­10­03 | 5bb0f205­d746­4e60­b3c3­0cb58075d656 |
| 2169 | 958 | Manajemen Sumber Daya Manusia | 1 | 34.91 | 2015­10­08 | c0d11e1c­6204­4a46­9ef6­baecddda2ab1 |
| 2172 | 958 | Manajemen Distribusi Ritel | 6 | 45.33 | 2015­10­18 | e7c1a632­d9e0­4655­bb4a­329a348d75c5 |
| 2193 | 958 | Studi Kelayakan Bisnis | 13 | 59.61 | 2015­10­30 | 116ff35d­6cd0­48cb­b307­32731b3c67a6 |
| 2270 | 958 | Studi Kelayakan Bisnis | 13 | 62.62 | 2015­10­03 | edacb7d0­25db­4dfd­8124­4bd8fd5ffb5c |
| 2668 | 958 | Evaluasi Kinerja | 12 | 82.41 | 2015­10­06 | a465c348­966e­42de­b14a­36e635301e2a |
| 2715 | 958 | Perilaku Organisasi | 15 | 67.66 | 2015­10­19 | f0568107­0486­408e­bef3­7cacf9663b0c |
+­­­­­­+­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­+­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
10 rows in set (0.02 sec)
mysql> select id, id_mhs, mata_kuliah, semester, nilai, updated, guid from tbl_nilai where id_mhs = 74;
+­­­­­­+­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­+­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
| id | id_mhs | mata_kuliah | semester | nilai | updated | guid |
+­­­­­­+­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­+­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
| 879 | 74 | Manajemen Kompensasi | 10 | 97.98 | 2015­10­13 | b8f9903f­989d­464b­bca1­7d8f689147b2 |
| 890 | 74 | Manajemen Produk & Harga | 9 | 49.50 | 2015­10­18 | 9b036b96­888b­4e62­a158­d33ac2f3f4ba |
| 1247 | 74 | Audit 1 | 9 | 81.01 | 2015­10­05 | c1e89f6c­28e2­4b8a­8fc2­dbeca5e1ba0d |
| 1695 | 74 | Manajemen Produk dan Harga | 8 | 39.17 | 2015­10­06 | 5e14640f­1ac6­4add­b9ca­ad1f17293dab |
| 1720 | 74 | Akuntansi Manajemen | 16 | 93.00 | 2015­10­23 | 198f3e12­ae64­48fa­967a­8ffcc9b01338 |
| 1884 | 74 | Bahasa Inggris | 3 | 6.96 | 2015­10­24 | 486e42a5­85f1­4a0b­96b1­6997ce705293 |
| 2475 | 74 | Pengantar Manajemen | 7 | 28.31 | 2015­10­29 | a007b6f1­e912­4d94­963c­05094adc4c5a |
| 2611 | 74 | Audit 1 | 3 | 55.46 | 2015­10­15 | a3613465­5967­45d7­a6a3­748915a391f6 |
| 2921 | 74 | Ekonomi 2 | 8 | 10.14 | 2015­10­09 | d4826e58­0174­4922­9682­16ea46065923 |
| 2957 | 74 | Bahasa Inggris | 9 | 26.33 | 2015­10­26 | 84bc611d­10dc­41aa­8297­67ff29e7ae0e |
+­­­­­­+­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­+­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
10 rows in set (0.02 sec)
•
•
ST: On Select

9. • Limiting to 1
mysql> select * from tbl_nilai where id_mhs = 435;
+­­­­+­­­­­­­­+­­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­+­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
| id | id_mhs | mata_kuliah | semester | nilai | updated | guid |
+­­­­+­­­­­­­­+­­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­+­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
| 30 | 435 | Ekonomi 2 | 11 | 58.40 | 2015­10­12 | 4ef8a9db­5dde­431e­99cd­493bacaeb342 |
+­­­­+­­­­­­­­+­­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­+­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
1 row in set (0.02 sec)
mysql> select * from tbl_nilai where id_mhs = 555 limit 1;
+­­­­­+­­­­­­­­+­­­­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­+­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
| id | id_mhs | mata_kuliah | semester | nilai | updated | guid |
+­­­­­+­­­­­­­­+­­­­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­+­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
| 674 | 555 | Ekonomi Makro | 11 | 61.29 | 2015­10­22 | df79768c­b385­475f­b25c­885a489c62fc |
+­­­­­+­­­­­­­­+­­­­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­+­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­+
1 row in set (0.01 sec)
ST: On Select

10. • MySQL DB Engine
• Storing temporary non essential value with heap
mysql> CREATE TABLE login_tracker(
user_id INT(11) NOT NULL,
login_time TIMESTAMP,
last_activity TIMESTAMP
) engine=memory;
mysql> INSERT INTO login_tracker(5, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP);
• Heap Limitation:
–Index usage: not optimal, limited conditional operator, can not be
ordered
–No support auto increment
–Not for text or blob
ST: HEAP TO THE RESCUE

11. UNDERSTANDING JOIN
• Asumsi
TABLE_A TABLE_B
id name id name
­­ ­­­­ ­­ ­­­­
1 Pirate 1 Rutabaga
2 Monkey 2 Pirate
3 Ninja 3 Darth Vader
4 Spaghetti 4 Ninja
• Inner Join on A.name = B.name
id name id name
­­ ­­­­ ­­ ­­­­
1 Pirate 2 Pirate
3 Ninja 4 Ninja

12. UNDERSTANDING JOIN
• Asumsi
TABLE_A TABLE_B
id name id name
­­ ­­­­ ­­ ­­­­
1 Pirate 1 Rutabaga
2 Monkey 2 Pirate
3 Ninja 3 Darth Vader
4 Spaghetti 4 Ninja
• Full Outer Join on A.name = B.name
id name id name
­­ ­­­­ ­­ ­­­­
1 Pirate 2 Pirate
2 Monkey null null
3 Ninja 4 Ninja
4 Spaghetti null null
null null 1 Rutabaga
null null 3 Darth Vader
–

13. UNDERSTANDING JOIN
• Asumsi
TABLE_A TABLE_B
id name id name
­­ ­­­­ ­­ ­­­­
1 Pirate 1 Rutabaga
2 Monkey 2 Pirate
3 Ninja 3 Darth Vader
4 Spaghetti 4 Ninja
• Left Outer Join on A.name=B.name
id name id name
­­ ­­­­ ­­ ­­­­
1 Pirate 2 Pirate
2 Monkey null null
3 Ninja 4 Ninja
4 Spaghetti null null
–

14. UNDERSTANDING JOIN
• Asumsi
TABLE_A TABLE_B
id name id name
­­ ­­­­ ­­ ­­­­
1 Pirate 1 Rutabaga
2 Monkey 2 Pirate
3 Ninja 3 Darth Vader
4 Spaghetti 4 Ninja
• How ?
id name id name
­­ ­­­­ ­­ ­­­­
2 Monkey null null
4 Spaghetti null null
–

15. UNDERSTANDING JOIN
• Asumsi
TABLE_A TABLE_B
id name id name
­­ ­­­­ ­­ ­­­­
1 Pirate 1 Rutabaga
2 Monkey 2 Pirate
3 Ninja 3 Darth Vader
4 Spaghetti 4 Ninja
• How ?
id name id name
­­ ­­­­ ­­ ­­­­
2 Monkey null null
4 Spaghetti null null
–

16. Partitioning
• Check Plugin
mysql> show plugins;
+­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­­­­­­­­­­+­­­­­­­­­+­­­­­­­­­+
| Name | Status | Type | Library | License |
+­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­­­­­­­­­­+­­­­­­­­­+­­­­­­­­­+
| binlog | ACTIVE | STORAGE ENGINE | NULL | GPL |
| partition | ACTIVE | STORAGE ENGINE | NULL | GPL |
| ARCHIVE | ACTIVE | STORAGE ENGINE | NULL | GPL |
| BLACKHOLE | ACTIVE | STORAGE ENGINE | NULL | GPL |
| CSV | ACTIVE | STORAGE ENGINE | NULL | GPL |
| FEDERATED | DISABLED | STORAGE ENGINE | NULL | GPL |
| MEMORY | ACTIVE | STORAGE ENGINE | NULL | GPL |
| InnoDB | ACTIVE | STORAGE ENGINE | NULL | GPL |
| MyISAM | ACTIVE | STORAGE ENGINE | NULL | GPL |
| MRG_MYISAM | ACTIVE | STORAGE ENGINE | NULL | GPL |
+­­­­­­­­­­­­+­­­­­­­­­­+­­­­­­­­­­­­­­­­+­­­­­­­­­+­­­­­­­­­+
10 rows in set (0.02 sec)
• Buat Partisi
CREATE TABLE tbl_patient (
ssn VARCHAR(35),
first_name VARCHAR(25) NOT NULL,
last_name VARCHAR(25) NOT NULL,
title VARCHAR(16) NOT NULL,
dob DATE,
registered DATE NOT NULL
)
PARTITION BY RANGE( YEAR(registered) ) (
PARTITION p0 VALUES LESS THAN (1985),
PARTITION p1 VALUES LESS THAN (1995),
PARTITION p2 VALUES LESS THAN (2005),
PARTITION p3 VALUES LESS THAN (2010),
PARTITION p4 VALUES LESS THAN MAXVALUE
);
•

17. Tree Structure
• Adjency List
mysql> CREATE TABLE category(
category_id INT AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(20) NOT NULL,
parent INT DEFAULT NULL
);
Mysql> SELECT * FROM category ORDER BY category_id;
+­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­+­­­­­­­­+
| category_id | name | parent |
+­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­+­­­­­­­­+
| 1 | ELECTRONICS | NULL |
| 2 | TELEVISIONS | 1 |
| 3 | TUBE | 2 |
| 4 | LCD | 2 |
| 5 | PLASMA | 2 |
| 6 | PORTABLE ELECTRONICS | 1 |
| 7 | MP3 PLAYERS | 6 |
| 8 | FLASH | 7 |
| 9 | CD PLAYERS | 6 |
| 10 | 2 WAY RADIOS | 6 |
+­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­+­­­­­­­­+
10 rows in set (0.00 sec)

18. Tree Structure
• Nested List
mysql> CREATE TABLE nested_category (
category_id INT AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(20) NOT NULL,
lft INT NOT NULL,
rgt INT NOT NULL
);
Mysql> SELECT * FROM category ORDER BY category_id;
+­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­+­­­­­+­­­­­+
| category_id | name | lft | rgt |
+­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­+­­­­­+­­­­­+
| 1 | ELECTRONICS | 1 | 20 |
| 2 | TELEVISIONS | 2 | 9 |
| 3 | TUBE | 3 | 4 |
| 4 | LCD | 5 | 6 |
| 5 | PLASMA | 7 | 8 |
| 6 | PORTABLE ELECTRONICS | 10 | 19 |
| 7 | MP3 PLAYERS | 11 | 14 |
| 8 | FLASH | 12 | 13 |
| 9 | CD PLAYERS | 15 | 16 |
| 10 | 2 WAY RADIOS | 17 | 18 |
+­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­+­­­­­+­­­­­+

19. Tree Structure
• Nested List
mysql> CREATE TABLE nested_category (
category_id INT AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(20) NOT NULL,
lft INT NOT NULL,
rgt INT NOT NULL
);
Mysql> SELECT * FROM category ORDER BY category_id;
+­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­+­­­­­+­­­­­+
| category_id | name | lft | rgt |
+­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­+­­­­­+­­­­­+
| 1 | ELECTRONICS | 1 | 20 |
| 2 | TELEVISIONS | 2 | 9 |
| 3 | TUBE | 3 | 4 |
| 4 | LCD | 5 | 6 |
| 5 | PLASMA | 7 | 8 |
| 6 | PORTABLE ELECTRONICS | 10 | 19 |
| 7 | MP3 PLAYERS | 11 | 14 |
| 8 | FLASH | 12 | 13 |
| 9 | CD PLAYERS | 15 | 16 |
| 10 | 2 WAY RADIOS | 17 | 18 |
+­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­+­­­­­+­­­­­+

20. Tree Structure
• Nested List
mysql> CREATE TABLE nested_category (
category_id INT AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(20) NOT NULL,
lft INT NOT NULL,
rgt INT NOT NULL
);
Mysql> SELECT * FROM category ORDER BY category_id;
+­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­+­­­­­+­­­­­+
| category_id | name | lft | rgt |
+­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­+­­­­­+­­­­­+
| 1 | ELECTRONICS | 1 | 20 |
| 2 | TELEVISIONS | 2 | 9 |
| 3 | TUBE | 3 | 4 |
| 4 | LCD | 5 | 6 |
| 5 | PLASMA | 7 | 8 |
| 6 | PORTABLE ELECTRONICS | 10 | 19 |
| 7 | MP3 PLAYERS | 11 | 14 |
| 8 | FLASH | 12 | 13 |
| 9 | CD PLAYERS | 15 | 16 |
| 10 | 2 WAY RADIOS | 17 | 18 |
+­­­­­­­­­­­­­+­­­­­­­­­­­­­­­­­­­­­­+­­­­­+­­­­­+