• SQL: Recursive query in MySQL


    DROP TABLE IF EXISTS `dudept`; CREATE TABLE `dudept` ( `Id` int(11) NOT NULL AUTO_INCREMENT comment ‘ID’, `deptCode` varchar(10) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL comment”, `deptName` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL comment”, `pCode` varchar(10) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL comment”, `ParentId`int(11) not null comment ‘Parent ID’, PRIMARY […]

  • Several circular dependency ways of spring bean


    What is circular dependence? Circular dependency is actually circular reference, that is, two or more beans hold each other, and finally form a closed loop. For example, a depends on B, B depends on C, and C depends on a. The following picture: Note that this is not a circular call of a function, but […]

  • How it enterprises choose container management platform


    For IT enterprises, it is difficult to determine which container management tool is the best. What is complex for one enterprise may be flexible and easy to expand for another. It teams usually decide which tool is suitable for them by considering the support and interoperability of tools. One it enterprise has 50 local data […]

  • Practical Case: Evolution of Distributed Architecture


    Preface With the scale of computer system becoming larger and larger, the architecture of centralized deployment of all business units on one or several mainframes has become increasingly unable to meet the needs of today’s computer systems. At the same time, with the emergence of microcomputers, more and more inexpensive PC has become the preferred […]

  • Daniel’s Zoo Keeper Notes


    Catalog Summary of ZooKeeper 2. ZooKeeper Data Model III. Operation in ZooKeeper Service Watch trigger 5. Examples of ZooKeeper applications Summary of ZooKeeper ZooKeeper is a high availability, high performance and consistent open source coordination service designed for distributed applications. It provides a basic service: distributed lock service. Because of ZooKeeper’s open source nature, our […]