Saeid Zebardast @saeid http://about.me/saeid saeid.zebardast@gmail.com

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Please Please Please Ask Questions

As Much As You Like• This is not a lecture!

- But an opportunity to learn from each other.

- If you haven’t seen some of these frameworks, methods, etc. It is OK!

- Let we know if you know

‣ Better ways

‣ Best practices

‣ My mistakes!

Introduction• What’s MySQL?

- Since 1995

- Written in C/C++

- RDMBS (Relational Database Management System)

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Installation• Just enter the following command:

- $ sudo apt-get install mysql-server mysql-client

• Check MySQL CLI:

- $ mysql -u root -p

- mysql> SHOW DATABASES;

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Execute SQL Statements• Interactively

- $ mysql [database]

‣ mysql> stmt;

• Command Line

- $ mysql [database] -e ‘stmt’

• A file or a pipe

- $ mysql [database] < stmt_file

- $ cat stmt_file | mysql [database]

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SQL Language• SQL (Structured Query Language)

- Provided by RDBMS

- Data Definition (DDL)

‣ CREATE TABLE, DROP DATABASE

- Data Manipulation (DDL)

‣ SELECT, INSERT, UPDATE, DELETE

- Data Control (DCL)

‣ GRANT, REVOKE

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Some of The Most Important SQL Commands

• SELECT - extracts data from a database

• UPDATE - updates data in a database

• DELETE - deletes data from a database

• INSERT INTO - inserts new data into a database

• CREATE DATABASE - creates a new database

• ALTER DATABASE - modifies a database

• USE DATABASE - choose a database to execute a statement

• CREATE TABLE - creates a new table

• ALTER TABLE - modifies a table

• DROP TABLE - deletes a table

• CREATE INDEX - creates an index (search key)

• DROP INDEX - deletes an index

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SQL Syntax• SQL is NOT case sensitive: select is the same as

SELECT

• Semicolon (;) after SQL Statements

- or \G

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Data Types Integer

Type Min Max 2^

TINYINT -128 127 2^7

SMALLINT -32,768 32,767 2^15

MEDIUMINT -8,388,608 8,388,607 2^23

INT -2,147,483,648 2,147,483,647 2^31

BIGINT -9,223,372,036,854,775,808 9,223,372,036,854,775,807 2^63

Note: If unsigned, the allowable range is from 0 to twice the Max.

Data Types Floating-point

Type Description

FLOAT(M,D)A small number with a floating decimal point. Size or Display length (M), Decimals (D) 0, 23

DOUBLE(M,D) A large number with a floating decimal point. 0, 53

DECIMAL(M,D) 0, 65

Data Types Date and Time

Type Description

DATE YYYY-MM-DD format. between 1000-01-01 and 9999-12-31.

DATETIME YYYY-MM-DD HH:MM:SS format. between 1000-01-01 00:00:00 and 9999-12-31 23:59:59.

TIMESTAMP stored as the number of seconds since the Unix epoch 1970-01-01 between 1970-01-01 00:00:01 and 2038-01-09 03:14:07.

TIME HH:MM:SS

YEAR 1901 to 2155

Data Types String

Type Description

CHAR A fixed-length string between 1 and 255 characters. right-padded with spaces.

VARCHAR A variable-length string between 1 and 255 characters. 0 to 65,535 in 5.0.3

TINYTEXTTINYBLOB up to 255 characters

TEXTBLOB up to 65,535 characters

MEDIUMTEXTMEDIUMBLOB up to 16,777,215 characters

LONGTEXTLONGBLOB up to 4,294,967,295 characters

ENUM List of items. For example: ENUM ('A', 'B', 'C')

Note: case sensitive on BLOBs and are not case sensitive in TEXT fields.

Operators (Most Used)

Operator Description

= (A = B) is not true.

!=<> (A != B) is true.

> (A > B) is not true.

< (A < B) is true.

>= (A >= B) is not true.

<= (A <= B) is true.

LIKE Simple pattern matching

BETWEEN ... AND ... Check whether a value is within a range of values

Basic Syntax• Create Database

- CREATE DATABASE db_name

• Create Table

- CREATE TABLE table_name (column_name column_type, …);

• Insert Data

- INSERT INTO table_name (field1, field2,...fieldN) VALUES (value1, value2, …valueN);

• Select Data

- SELECT field1, field2,...fieldN table_name1, table_name2... [WHERE condition1 [AND -OR condition2]….]

• Update Data

- UPDATE table_name SET field1=new-value1, field2=new-value2 [WHERE Clause]

• Delete Data

- DELETE FROM table_name [WHERE Clause]

• Sorting Result

- SELECT field1, field2,...fieldN table_name1, table_name2… ORDER BY field1, [field2...] [ASC [DESC]]

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Exercise 1 Data Definition, Data Control

• Create database `workshop`

- mysql> CREATE DATABASE `workshop`;mysql> USE `workshop`;

• Grant all privileges to the database user `worker`

- mysql> GRANT ALL PRIVILEGES on `workshop`.* to `worker`@localhost identified by ‘123456';

- mysql> exit;

• Create table `workshops_list`

- mysql> CREATE TABLE `workshops_list` ( `id` INT(11) UNSIGNED NOT NULL AUTO_INCREMENT, `title` VARCHAR(255) NOT NULL, `description` MEDIUMTEXT DEFAULT NULL, PRIMARY KEY(`id`) );

- DESC `workshops_list`;

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Exercise 2 Data Manipulation

• Show data

- mysql> SELECT * FROM `workshops_list`;

• Insert data

- mysql> INSERT INTO `workshops_list`(`title`) VALUES ('MySQL Workshop'), ('Java Workshop'), ('Ubuntu'), ('Windows 10’);

- mysql> SELECT * FROM `workshops_list` \G

• Update data

- mysql> UPDATE `workshops_list` SET `description` = 'Introduce MySQL database' WHERE id = 1;

- …

- mysql> SELECT * FROM `workshops_list` ORDER BY `id` DESC;

• Remove data

- mysql> DELETE FROM `workshops_list` WHERE title = 'Windows 10’;

- mysql> SELECT * FROM `workshops_list` ORDER BY `title` ASC;

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Exercise 3 Export and Import

• Export database dump. you might want to take a look at the contents.

- $ mysqldump -u worker -p workshop > workshop.sql

- $ less workshop.sql

• Delete database `workshop`

- mysql> DROP DATABASE `workshop`;

• Import database dump file.

- $ mysql -u worker -p < workshop.sql

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Read The F* Manual• RTFM

- https://dev.mysql.com/doc/

• Help

- mysql> HELP;

- mysql> HELP CONTENTS;

- mysql> HELP SELECT;

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Thank You