funny cmd commands

Installation tutorials for 1.mavenis: http://maven.apache.org/download.cgiAfter entering this pageClick Download, then unzip, I change the directory name to MAVEN, directory structure as shownBelow we configure the environment variablesThis is maven_home:At the end of the path variable, add;%maven_home%\bin%; The number cannot be thrown away.Enter mvn-version in cmd, and if the version information appears, install it correctly.2.maven display MVN is n

What is said on the Internet, I summed up a bit, and then I recently encountered a situation online as if no one had encountered, posted here1, environment variables, generally can compile files, it is not the amount of environmental variables2, without the package name, such as the AAA package below the Hello.java compiled Hello.class runtime to write this Java Aaa.hello3, also I encountered a situation, the file path in Chinese, and then changed the folder name to the English name to solve.Run

table name;Backup table: Mysqlbinmysqldump-h (IP)-uroot-p (password) databasename tablename > Tablename.sqlRecovery table: Mysqlbinmysql-h (IP)-uroot-p (password) databasename tablename Add column: ALTER TABLE T2 ADD C INT UNSIGNED not NULL auto_increment,add INDEX (c);Modify column: ALTER TABLE T2 MODIFY A TINYINT not NULL, change b C CHAR (20);Delete column: ALTER TABLE T2 DROP column C;Backup database: Mysql\bin\mysqldump-h (IP)-uroot-p (password) databasename > Database.sqlRecovery database