文档已移动

MySQL is a typical and widely-chosen open-source relational database administration system (RDBMS). On this article, we talk about MySQL instructions and supply a cheat sheet of widespread MySQL queries to assist customers work with MySQL extra effectively and successfully.

What’s MySQL Database?

MySQL is an open-source RDBMS developed by Oracle Company. It was initially developed and launched by Swedish firm MySQL AB on Could 23, 1995.

MySQL performs nicely and is dependable with enterprise intelligence (BI) purposes, particularly read-heavy BI purposes. MySQL and InnoDB collectively present nice learn/write speeds for OLTP eventualities and work nicely with excessive concurrency eventualities. Furthermore, MySQL affords two totally different editions, open-source MySQL Neighborhood Server and Proprietary Enterprise Server.

MySQL works on many system platforms, together with Linux, Home windows, macOS, and so forth. Additionally it is one of the steady database administration programs, and a few cloud platforms supply it “as a service.” Cloud-based MySQL companies embrace Oracle MySQL Cloud Service, Amazon Relational Database Service, and Azure Database for MySQL.

Learn: Relational Database Administration Programs (RDBMS): MSSQL vs MySQL

MySQL Instructions

MySQL makes use of instructions to speak with the MySQL database by creating queries with information and performing particular duties and capabilities. The instructions are directions coded into SQL (structured question language) statements. To jot down a question requires a set of predefined code that’s comprehensible to the database.

MySQL helps all SQL-standard varieties of information in a number of classes together with Numeric, Date and Time, String, and Spatial information varieties. The string information varieties embrace Character string and Byte string. MySQL additionally implements spatial extensions as a subset of SQL with Geometry Sorts atmosphere following the Open Geospatial Consortium (OGC) specification.

MySQL Cheat Sheet

Under are a few of the mostly used MySQL instructions and statements that assist customers work with MySQL extra simply and successfully. On this article, we current briefly probably the most generally used instructions – together with MySQL command-line shopper instructions – and the instructions for working with databases, tables, indexes, views, triggers, procedures, and capabilities.

Learn: Finest Database Software program for Builders

MySQL command-line shopper Instructions

Under is a listing of MySQL command-line shopper instructions:

mysql -u [username] -p;      # Connect with MySQL server
mysql -u [username] -p [database];   # Connect with MySQL Server
exit;                                # Exit mysql command-line shopper
mysqldump -u [username] -p [database] > data_backup.sql; # Export information utilizing mysqldump software
mysql> system clear;  # Clear MySQL display console for Linux

The MySQL command-line shopper instructions can be found on Linux for clearing the MySQL display console window, and there’s no shopper command accessible on Home windows OS.

MySQL Instructions for Working with Databases

Under are MySQL instructions used for working with databases:

CREATE DATABASE [IF NOT EXISTS] database_name; # Create a database within the server
SHOW DATABASE; # Present all accessible databases
USE database_name; # Use a database with a specified identify
DROP DATABASE [IF EXISTS] database_name; # Drop a database with a specified identify

MySQL Instructions for Working with Tables

Listed below are MySQL instructions for working with tables in a database:

CREATE TABLE [IF NOT EXISTS] table_name(column_list,...); # Create a brand new desk
SHOW TABLES; # Present all tables within the database
DROP TABLE [IF EXISTS] table_name; # Drop a desk from the database

Generally Used MySQL Instructions

Under is a listing of probably the most generally used MySQL instructions for database builders and database directors utilizing MySQL databases:

ALTER

ALTER TABLE table_name ADD [COLUMN] column_name;
ALTER TABLE table_name DROP [COLUMN] column_name;
ALTER TABLE table_name MODIFY column_name kind;
ALTER TABLE table_name MODIFY column_name kind NOT NULL ...;
ALTER TABLE table_name CHANGE old_column_name new_column_name kind;
ALTER TABLE table_name CHANGE old_column_name new_column_name kind NOT NULL ...;
ALTER TABLE table_name MODIFY column_name kind FIRST;
ALTER TABLE table_name MODIFY column_name kind AFTER another_column;
ALTER TABLE table_name CHANGE old_column_name new_column_name kind FIRST;
ALTER TABLE table_name CHANGE old_column_name new_column_name kind AFTER another_column;
ALTER TABLE table_name ALTER column_name SET DEFAULT ...;
ALTER TABLE table_name ALTER column_name DROP DEFAULT;
ALTER TABLE table_name ADD new_column_name kind;
ALTER TABLE table_name ADD new_column_name kind FIRST;
ALTER TABLE table_name ADD new_column_name kind AFTER another_column;
ALTER TABLE table_name ADD INDEX [name](column, ...);
ALTER TABLE table_name ADD PRIMARY KEY (column_name,...);
ALTER TABLE table_name DROP PRIMARY KEY;

SELECT

SELECT * FROM table_name;
SELECT * FROM table1, table2, …;
SELECT column_name FROM table_name;
SELECT column1, column2, ... FROM table_name;
SELECT column1, column2, ... FROM table1, table2, …;
SELECT select_list FROM table_name WHERE situation;
SELECT select_list FROM desk GROUP BY column1, column2, ...;
SELECT select_list FROM desk GROUP BY column_name HAVING situation;
SELECT COUNT(*) FROM table_name;
SELECT DISTINCT (column_name) FROM    table_name;
SELECT select_list FROM desk ORDER BY column_name;
SELECT select_list FROM desk ORDER BY column1 ASC [DESC], column2 ASC [DESC];
SELECT column_name AS alias_name, expression AS alias, ... FROM table_name;
SELECT select_list FROM table_name WHERE column LIKE '%sample%';
SELECT select_list FROM table_name WHERE column RLIKE 'regular_expression';

SELECT – JOIN

SELECT select_list FROM table1 INNER JOIN table2 ON situation;
SELECT select_list FROM table1 LEFT JOIN table2 ON situation;
SELECT select_list FROM table1 RIGHT JOIN table2 ON situation;
SELECT select_list FROM table1 CROSS JOIN table2;

DESCRIBE

DESCRIBE table_name;
DESCRIBE table_name column_name;

INSERT INTO

INSERT INTO desk (column_list) VALUES(value_list);
INSERT INTO desk (column_list) VALUES(list1), (list2), ...;

UPDATE

UPDATE table_name SET column1 = value1, ...;
UPDATE table_name SET column_1 = value_1, ... WHERE situation;
UPDATE table1, table2 INNER JOIN table1 ON table1.column1 = table2.column2 SET column1 = value1, WHERE situation;

DELETE

DELETE FROM table_name;
DELETE FROM table_name WHERE situation;
DELETE table1, table2 FROM table1 INNER JOIN table2 ON table1.column1= table2.column2 WHERE situation;

INDEX

CREATE INDEX index_name ON table_name (column,...);
DROP INDEX index_name;
CREATE UNIQUE INDEX index_name ON table_name (column,...);

VIEW

CREATE VIEW [IF NOT EXISTS] view_name AS  select_statement;
CREATE VIEW [IF NOT EXISTS] view_name AS select_statement WITH CHECK OPTION;
CREATE OR REPLACE view_name AS select_statement;
DROP VIEW [IF EXISTS] view_name;
DROP VIEW [IF EXISTS] view1, view2, ...;
RENAME TABLE view_name TO new_view_name;
SHOW FULL TABLES [ IN  database_name] WHERE table_type="VIEW";

TRIGGER

CREATE TRIGGER trigger_name  AFTER  UPDATE ON table_name FOR EACH ROW trigger_body;
SHOW TRIGGERS [ IN database_name] [LIKE 'pattern' | WHERE search_condition];
DROP TRIGGER [IF EXISTS] trigger_name;

PROCEDURE

DELIMITER $$ CREATE PROCEDURE procedure_name (parameter_list) BEGIN physique; END $$ DELIMITER;
DROP PROCEDURE [IF EXISTS] procedure_name;
SHOW PROCEDURE STATUS [LIKE 'pattern' | WHERE search_condition];

FUNCTION

DELIMITER $$ CREATE FUNCTION function_name(parameter_list) RETURNS datatype [NOT] DETERMINISTIC BEGIN -- statements END $$ DELIMITER;
DROP FUNCTION [IF EXISTS] function_name;
SHOW FUNCTION STATUS [LIKE 'pattern' | WHERE search_condition];

Customers and Privileges

CREATE USER 'person'@'localhost';
GRANT ALL PRIVILEGES ON base.* TO 'person'@'localhost' IDENTIFIED BY 'password';
GRANT SELECT, INSERT, DELETE ON base.* TO 'person'@'localhost' IDENTIFIED BY 'password';
REVOKE ALL PRIVILEGES ON base.* FROM 'person'@'host';
REVOKE ALL PRIVILEGES, GRANT OPTION FROM 'person'@'host'; 
FLUSH PRIVILEGES;
SET PASSWORD = PASSWORD('new_pass');
SET PASSWORD FOR 'person'@'host' = PASSWORD('new_pass');
SET PASSWORD = OLD_PASSWORD('new_pass');
DROP USER 'person'@'host';

Conclusion of MySQL Cheat Sheet

MySQL has a status as a particularly quick database for read-heavy workloads, and it’s nice at read-heavy processes. The MySQL cheat sheet consists of probably the most generally used instructions and statements to assist MySQL database customers handle it extra successfully and simply.

Learn extra database administration and database programming tutorials.

Source link