UNIT1---INTRODUCTION TO MYSQL

MYSQL INTRODUCTION

—MySQL is an open source, fast reliable, and flexible relational database management system, used with PHP.

—MySQL is a fast, easy-to-use RDBMS being used for many small and big businesses.

—MySQL is developed, marketed and supported by MySQL AB, which is a Swedish company. 

MYSQL DATA TYPES

—BIT.

—CHAR.

—DATETIME.

—DECIMAL.

—ENUM.

—JSON.

—TIME.

—TIMESTAMP.

CREATE A MYSQL TABLE

—A database table has its own unique name and consists of columns and rows.

—The CREATE TABLE statement is used to create a table in MySQL.

Ex:

CREATE TABLE MyGuests (
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
firstname VARCHAR(30) NOT NULL,
lastname VARCHAR(30) NOT NULL,
email VARCHAR(50),
reg_date TIMESTAMP )

INSERT DATA INTO MYSQL

—After a database and a table have been created, we can start adding data in them.

Here are some syntax rules to follow:

—String values inside the SQL query must be quoted 

—Numeric values must not be quoted 

—The word NULL must not be quoted

Ex:

INSERT INTO table_name (column1, column2, column3,...)
 VALUES (value1, value2, value3,...)

SELECT DATA FROM A MYSQL

žThe SELECT statement is used to select data from one or more tables.

žwe can use the * character to select ALL columns from a table.

EXAMPLE

  SELECT * FROM table_name ;

Replace Data From a MySQL

The REPLACE() function

žreplaces all occurrences of a substring within a string, with a new substring.

EXAMPLE

  REPLACE(string, from_string, new_string)

DELETE DATA FROM A MYSQL

—The DELETE statement is used to delete records from a table:

DELETE FROM table_name

WHERE some_column = some_value

Update Data In a MySQL

—The UPDATE statement is used to update existing records in a table:

UPDATE table_name

SET column1=value, column2=value2,...

WHERE some_column=some_value ;