JDBC连接postgresql数据库

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>postgresql-project</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>42.2.2</version>
        </dependency>
    </dependencies>
</project>

package com.uncle;


import java.sql.Connection;
import java.sql.DriverManager;

/**
 * @program: postgresql-project
 * @description: 连接postgresql
 * @author: Sun Jinxin
 * @create: 2021/11/24 10:35
 */
public class PostgresqlJDBC {
    
    

    public static void main(String args[]) {
    
    
        Connection c = null;
        try {
    
    
            Class.forName("org.postgresql.Driver");
            c = DriverManager
                    .getConnection("jdbc:postgresql://localhost:5432/postgres",
                            "postgres", "123456");
        } catch (Exception e) {
    
    
            e.printStackTrace();
            System.err.println(e.getClass().getName()+": "+e.getMessage());
            System.exit(0);
        }
        System.out.println("Opened database successfully");
    }

}
    

package com.uncle;


import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;

/**
 * @program: postgresql-project
 * @description: 连接postgresql
 * @author: Sun Jinxin
 * @create: 2021/11/24 10:35
 */
public class PostgresqlJDBC {
    
    

    public static void main(String args[]) {
    
    
        Connection c = null;

        Statement stmt = null;
        try {
    
    
            Class.forName("org.postgresql.Driver");
            c = DriverManager
                    .getConnection("jdbc:postgresql://localhost:5432/postgres",
                            "postgres", "123456");

            stmt = c.createStatement();
            String sql = "CREATE TABLE COMPANY02 " +
                    "(ID INT PRIMARY KEY     NOT NULL," +
                    " NAME           TEXT    NOT NULL, " +
                    " AGE            INT     NOT NULL)";
            stmt.executeUpdate(sql);
            stmt.close();
            c.close();

        } catch (Exception e) {
    
    
            e.printStackTrace();
            System.err.println(e.getClass().getName()+": "+e.getMessage());
            System.exit(0);
        }
        System.out.println("成功了，欧耶！！！");
    }

}
    

package com.uncle;


import org.postgresql.util.PSQLException;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.Statement;
import java.util.Random;
import java.util.UUID;

/**
 * @program: postgresql-project
 * @description: 连接postgresql
 * @author: Sun Jinxin
 * @create: 2021/11/24 10:35
 */
public class PostgresqlJDBC {
    
    

    public static void main(String args[]) {
    
    
        Connection c = null;

        try {
    
    
            Class.forName("org.postgresql.Driver");
            c = DriverManager
                    .getConnection("jdbc:postgresql://localhost:5432/postgres",
                            "postgres", "123456");
            c.setAutoCommit(false);

            System.out.println("连接数据库成功！");

            String sql = "INSERT INTO postgresqltable (ID,NAME,AGE) "
                    + "VALUES (?, 'Sjx', 18);";

            for (int i = 0; i < 1000000; i++) {
    
    
                PreparedStatement preparedStatement = c.prepareStatement(sql);
                preparedStatement.setString(1, UUID.randomUUID().toString());
                preparedStatement.executeUpdate();
                System.out.println("还有 -》 "+(1000000-i) + " 次");

            }

            c.commit();
            c.close();

        } catch (Exception e) {
    
    
            e.printStackTrace();
            System.err.println(e.getClass().getName()+": "+e.getMessage());
            System.exit(0);
        }
        System.out.println("数据增加成功");
    }

}
    

explain analyze   select * from postgresqltable;