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The separation of reading and writing and load balancing of MySQL database are generally realized by the third-party software. It can also be implemented through MySQL driver, such as com.mysql.jdbc.ReplicationDriver. Website: Multi host connection configuration 1. Primary / secondary configuration 2. Load connection configuration 3. Primar ...

General introduction of the project Case: the realization of commodity browsing record Model 1 (Jsp+Javabean) implementation Implement DBHelper class Create entity class Create business logic class (DAO) Create page layer DBHelper class design First copy the package of the drive rack to the lib f ...

The problem of inserting data into mysql database to display garbled code When you are doing a java web project, sometimes you will encounter the problem of "random code"? "When you add a database to the database. The main solutions to this problem are as follows: First: make sure the character set fi ...

1, Scheduled backup of database Backup command Mysql backup instructions: 1. Specify database: mysqldump -h localhost -uroot -proot tuser>d:\user_2017-12-25_15-42-10.sql tuser: database name User? 2017-12-25? 15-42-10.sql: filename 2. Specify multiple tables in the database: mysqldump -h localhost -uroot -proot --databases tuser - ...

The implementation of Group group get Top N method in SQL is reproduced from https://www.2cto.com/database/201303/194530.html There is a product table, which contains four fields: id, name, city and addtime. Because the report needs to be grouped by city, and the latest 10 products of each city are counted, 1 million data is inserted into the ...

1. if statement: drop function if exists hello; create function hello(a int) returns varchar (255) begin declare x varchar(255) default ' x '; select `name` into x from gl_dept where id = a; -- if start if x = 'Taobao online shop 2' THEN set x = '2'; elseif x = 'Taobao online shop 3' THEN set x = ...

Analyzing the cost of SQL execution is an important way to optimize SQL. MySQL can record the resource cost of SQL statements, such as IO, context switch, CPU, Memory, etc. by setting the profiling parameter Viewing the profiling system variable mysql> show variables like '%profil%'; +------------------------+-------+ | Variable_name ...

MySql provides a simple read-write separation method - replication. First look at the specific demo package test1; import java.sql.Connection; import java.sql.ResultSet; import java.sql.Statement; import java.util.Properties; import com.mysql.jdbc.Driver; import com.mysql.jdbc.ReplicationDriver;; public class Conn ...

1 no previous code format optimization Commodity //The advanced query object of goods encapsulates the data of the advanced query form of goods. public class ProductQueryObject extends BaseQueryObject{ private List<String> conditions = new ArrayList<>(); //SQL for splicing query conditions p ...

~~MySQL multi-source replication enables Slave to receive transactions from multiple direct masters in parallel. Multi source replication can be used to back up multiple servers to a single server, Merge Table shards, and merge data from multiple servers to a single server. When applying transactions, multi-source replication does not impleme ...