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MySQL


MySQL




MySQL is an open source database management software that helps users store, organize, and retrieve data. It is a very powerful DBMS with a lot of flexibility
 
quickinstallation of MySQL server
sudo apt-get update
sudo apt-get install mysql-server
Once you have MySQL installed on your droplet, you can access the MySQL shell by typing the following command into terminal:
mysql -u root -p
All MySQL commands end with a semicolon; if the phrase does not end with a semicolon, the command will not execute.

You can quickly check what databases are available by typing:
SHOW DATABASES;
Creating a database is very easy:
CREATE DATABASE database name;
You would delete a MySQL database with this command:
DROP DATABASE database name;

Let’s open up the database we want to use:
 USE databasename;
you can also see an overview of the tables that the database contains.
 SHOW tables; 

Let’s create a new MySQL table:
CREATE TABLE potluck (id INT NOT NULL PRIMARY
KEY AUTO_INCREMENT, 

name VARCHAR(20),

food VARCHAR(30),

confirmed CHAR(1), 

signup_date DATE);
We can remind ourselves about the table’s organization with this command:
 DESCRIBE potluck;
Use this format to insert information into each row:
INSERT INTO
`potluck` (`id`,`name`,`food`,`confirmed`,`signup_date`) VALUES
(NULL, "John", "Casserole","Y",
'2012-04-11');
We can take a look at our table:
 SELECT * FROM potluck;
we can update some data
UPDATE `potluck` 

SET 

`confirmed` = 'Y' 

WHERE
`potluck`.`name` ='Sandy';
 Modifying tables

ALTER TABLE potluck ADD email VARCHAR(40);
ALTER TABLE potluck ADD email VARCHAR(40)
AFTER name; 
ALTER TABLE potluck DROP email;

you can also delete rows from the table with the following command:
DELETE from [table name] where [column name]=[field text];
DELETE from potluck  where name='Sandy';

 
exiting from mysql

type the command      exit


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