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安踏跑鞋便宜推荐100左右 MySQL Online Editor

MySQL online editor

Write, Run & Share MySQL queries online using OneCompiler's MySQL online editor and compiler for free. It's one of the robust, feature-rich online editor and compiler for MySQL. Getting started with the OneCompiler's MySQL editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'MySQL' and start writing queries to learn and test online without worrying about tedious process of installation.

About MySQL

MySQL is a open-source, free and very popular relational database management system which is developed, distributed and supported by Oracle corporation.

Key Features: Open-source relational database management systems. Reliable, very fast and easy to use database server. Works on client-server model. Highly Secure and Scalable High Performance High productivity as it uses stored procedures, triggers, views to write a highly productive code. Supports large databases efficiently. Supports many operating systems like Linux*,CentOS*, Solaris*,Ubuntu*,Windows*, MacOS*,FreeBSD* and others. Syntax help Commands 1. CREATE CREATE TABLE table_name ( column1 datatype, column2 datatype, ....); Example CREATE TABLE EMPLOYEE ( empId INTEGER PRIMARY KEY, name TEXT NOT NULL, dept TEXT NOT NULL ); 2. ALTER ALTER TABLE Table_name ADD column_name datatype; Example INSERT INTO EMPLOYEE VALUES (0001, 'De', 'Sales'); 3. TRUNCATE TRUNCATE table table_name; 4. DROP DROP TABLE table_name; 5. RENAME RENAME TABLE table_name1 to new_table_name1; 6. COMMENT Single-Line Comments: --Line1; Multi-Line comments: /* Line1, Line2 */ DML Commands 1. INSERT INSERT INTO table_name (column1, column2, column3, ...) VALUES (value1, value2, value3, ...);

Note: Column names are optional.

Example INSERT INTO EMPLOYEE VALUES (0001, 'Ava', 'Sales'); 2. SELECT SELECT column1, column2, ... FROM table_name [where condition]; Example SELECT * FROM EMPLOYEE where dept ='sales'; 3. UPDATE UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE condition; Example UPDATE EMPLOYEE SET dept = 'Sales' WHERE empId='0001'; 4. DELETE DELETE FROM table_name where condition; Example DELETE from EMPLOYEE where empId='0001'; Indexes 1. CREATE INDEX CREATE INDEX index_name on table_name(column_name); To Create Unique index: CREATE UNIQUE INDEX index_name on table_name(column_name); 2. DROP INDEX DROP INDEX index_name ON table_name; Views 1. Create a View Creating a View: CREATE VIEW View_name AS Query; 2. How to call view SELECT * FROM View_name; 3. Altering a View ALTER View View_name AS Query; 4. Deleting a View DROP VIEW View_name; Triggers 1. Create a Trigger CREATE TRIGGER trigger_name trigger_time trigger_event ON tbl_name FOR EACH ROW [trigger_order] trigger_body /* where trigger_time: { BEFORE | AFTER } trigger_event: { INSERT | UPDATE | DELETE } trigger_order: { FOLLOWS | PRECEDES } */ 2. Drop a Trigger DROP TRIGGER [IF EXISTS] trigger_name; Stored Procedures 1. Create a Stored Procedure CREATE PROCEDURE sp_name(p1 datatype) BEGIN /*Stored procedure code*/ END; 2. How to call Stored procedure CALL sp_name; 3. How to delete stored procedure DROP PROCEDURE sp_name; Joins 1. INNER JOIN SELECT * FROM TABLE1 INNER JOIN TABLE2 where condition; 2. LEFT JOIN SELECT * FROM TABLE1 LEFT JOIN TABLE2 ON condition; 3. RIGHT JOIN SELECT * FROM TABLE1 RIGHT JOIN TABLE2 ON condition; 4. CROSS JOIN SELECT select_list from TABLE1 CROSS JOIN TABLE2;

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