今天在安装软件的时候出现了Package has no installation candidate的问题，如：
# apt-get install
Reading package lists... Done
Building dependency tree... Done
Package aptitude is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package has no installation candidate
解决方法如下：
# sudo apt-get update
# sudo apt-get upgrade
# sudo apt-get install ……
CREATE TABLE user (id INT AUTO_INCREMENT PRIMARY KEY NOT NULL,name VARCHAR(255),gender CHAR,birthday DATE);
insert into user (name,gender,birthday) values ('ernest','1','1999-01-01');
1.Open Windows manu from Eclipse
2.Windows ->Preferences->Keys
3.Type Command:Content Assist for In Dialogs and Windows
4.Binding:Alt+/ --(or define any key)
