from: http://tecadmin.net/install-java-8-on-centos-rhel-and-fedora/ After a long wait, finally Java SE Development Kit 8 is available to download. JDK Read More
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http://dba.stackexchange.com/questions/97095/set-session-custom-variable-to-store-user-id Read More
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PostgreSQL Cheat Sheet CREATE DATABASE CREATE TABLE (with auto numbering integer id) Add a primary key Create an INDEX Backup a database (command line Read More
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https://zh.wikipedia.org/wiki/PostgreSQL PostgreSQL是自由的对象-关系型数据库服务器（数据库管理系统），在灵活的BSD-风格许可证下发行。它在其他开放源代码数据库系统（比如MySQL和Firebird），和专有系统比如Oracle、Sybase、IB Read More
http://stackoverflow.com/questions/1293330/how-can-i-do-an-update-statement-with-join-in-sql create table sale ( id int, udid int, assid int ) create table ud ( id int, assid int ) select * from ... Read More