MySQL创建、修改和删除表（国外英文资料）.docVIP

MySQL创建、修改和删除表（国外英文资料）How to log in native MySQL:Run - CMD enter - mysql-h localhost - u root - p enter the password: 12345; The \ G \ G endsCreate database:CREATE DATABASE name;The database name represents the database name to be created.Display the existing database:SHOW the DATABASES;Delete database:DROP DATABASE DATABASE name;View the databases storage engine:SHOW ENGINES \ GOr: SHOW VARIABBLES LIKE have %;View the default storage engine:SHOW VARIABLES LIKE storage_engine;The table structure of the table created in the InnoDB storage engine is stored in.frm files.The MyISAM storage engine supports three different storage formats, static, dynamic and compressed (myisampack tool creation).File extension: FRM (the structure of the storage table), MYD (storage data), and MYI (storage index).CREATE a TABLEs SQl statement: CREATE TABLESyntax: CREATE TABLE TABLE name (attribute name data type [integrity constraint],Attribute name data type [integrity constraint],...Attribute name data type (no comma after note));Table name - the name of the table created;Name of the property name - the field in the table;Data type of data type - the data type of the field;Integrity constraints - specify certain special constraints for fields;Note: USE the USE database name before you create it. Select the required data.Integrity constraints: PRIMARY KEY (identifies that property as the PRIMARY KEY of the table); FOREIGN KEY (identifies the FOREIGN KEY to this table); NOT NULL (identifies that attribute cannot be empty); UNIQUE (the only one that identifies the attribute); AUTO_INCREMENT (identifies the value of this attribute automatically increases); DEFAULT (setting the DEFAULT for this property)Set the primary key of the table:Single field PRIMARY KEY syntax: attribute name data type PRIMARY KEYMulti-field PRIMARY KEY syntax: PRIMARY KEY (attribute name 1, attribute name 1,..., attribute name n).For example: CREATE TABLE example2 (stu_id INT,Course_id INT,Grade FLOAT,PRIMARY KEY (