Programmer Think

Create a database create database database name [other options]; Create database tables create table Table Name(Column Statement); ## Taking the creation of students table as an example, the table will store such contents as student number (id), name (name), sex (age), contact telephone (tel): create table students ( id int ...

Lao Zhang Mei is not only a fan of Jin Yong, but also a fan of the Three Kingdoms. I like to watch the fighting between Zhuge Liang of Shu State and Sima Yi of Wei State. The use of all kinds of magic tricks is classic. In view of the management of MySQL database, Mr. Zhang also has many ingenious ideas, which will be introduced to you one by o ...

I. Achieving Requirements 1. The responsibility of the data access layer is to add, delete and modify the database, so it can be very single. It only needs one inteface to do it. 2. Automated ORM is not conducive to the optimization of SQL and the customization of SQL, so TeaFrameWork ORM is ready to be implemented in a semi-automatic way. De ...

1. Create a dynamic web project 2. Importing the jar packages needed by Spring Mvc (you can find them online, there are many resources) The first two parts are not described in detail, but the second part is the formal code.~ First of all, there is a web.xml file, which belongs to the large configuration file. As long as you write login, you ca ...

1. Install elastic search The first time to use apt-get installation method, should be the software source is not set to the latest, the result of the installation version of 1.7x, decisive deletion. For the second time, download and install the zip package of elastic search directly. wget https://artifacts.elastic.co/downloads/elasticsearch/ ...

client initiates a connection request, shakes hands three times and exchanges validation information. How does mysql complete the validation work during this period? Process (three handshakes) How information is encrypted client: hash_stage1 = sha1(password) hash_stage2 = sha1(hash_stage1) reply = sha1(scramble, hash_stage2) ^ hash_stage1 ...

In MySQL replication environments, we usually judge SLAVE latency only based on the value of Seconds_Behind_Master. This is acceptable in most cases, but not accurate enough, and more factors should be taken into account. First, let's look at the state of SLAVE: > show slave status\G *************************** 1. row *************** ...

Background Recently, at 05:00 a.m., I always get warnings from the SQL firewall: group_name id user host db command time info state BASE 1059712468 xx xx.xx.xx.xx aea Query 34 UPDATE approve SET operator = 0', operator_name ='system', comment ='departure', status ='1'WHERE (id = 48311') updating When I first saw this data, the first react ...

When analyzing the AWR report of ORACLE, we found that the SQL ordered by Executions (recorded TOP SQL sorted by the number of executions of SQL). This sort shows the number of executions of SQL within the scope of monitoring.) There is a very frequent execution of SQL statements, executing tens of thousands of times in an hour:   update seq$ s ...

Author: Kentpeng   For reprinting, please specify the source: http://www.cnblogs.com/xieyupeng/p/7476717.html    1. Cursor (Cursor) If you have the concept of collections in your java program, then you will also use multiple records in pl/sql, at which point we will use cursors, which can store multiple pieces of data returned by queries. Gra ...