Getting Started with MySQL

Login to MySQL 

mysql -u root -p

Then enter the password.

quit MySQL  

exit

Operators and Functions

1 Character functions LIKE(), CONCAT();

2 Numerical operators and functions

CEIL() rounds up, FLOOR() rounds down, MOD rounding, DIV rounding, POWER() exponentiation, ROUND() rounding, TRUNCATE() number truncation;

3 Comparison operators and functions

BETWEEN...AND ,IN ,IS

4 Date Time Functions

NOW(), CURDATE(), CURTIME(); DATE_ADD(), DATEDIFF(); DATEo_FORMAT

5 Information functions

CONNECTION_ID(), DATABASE(), LAST

6 Aggregate functions

AVG(), COUNT(), MIN(), MAX(), SUM()

7 Encryption functions

MD5(), PASSWORD();

Introduction to custom functions

There are two necessary conditions for a custom function: 1 Parameters: Parameters can have zero or more 2 Return values: There can only be one return value

A function body with a composite structure needs to be included with BEGIN...END

MySQL stored procedure

Stored procedure: is a precompiled collection of sql statements and control statements, stored by name and processed as a unit

Parameters: input type output type input && output

CREATE: CREATE PEOCEDURE

Note: (1) When creating a stored procedure or custom function, use delimiter to modify the delimiter

(2) If the function body or procedure body has multiple statements, it needs to be included in the BEGIN END statement block

(3) The stored procedure needs to be called using CALL