[JavaSE] JDBC programming of Java

JDBC creation process

  • Load database driver
  • Create database connection
  • Create operation command
  • Execute SQL statement
  • Process return result set
  • Close result set
  • Close operation command
  • Close connection

actual combat

First load the driver
Project right click to find Open Module Settings open

After opening, do the following

Find the driver you downloaded in the local file

Then apply, ok. That's all
Click lib under the project, as shown in the figure, to load the driver successfully

import java.sql.*;
import java.time.LocalDateTime;
public class TestJDBC {
    public static void main(String[] args) {
        try {
        //1 / load drive
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }


        //2. Connect to database
        //jdbc:database://host:port/databaseName?p1=v1&p2=v2
        try {
            Connection connection = DriverManager.getConnection("jdbc:MySQL://localhost:3306/memo?useSSL=false", "root", "123456");


            //3. Create command
            Statement statement = connection.createStatement();

            //4. Prepare sql and execute
            ResultSet resultSet = statement.executeQuery("select id,name,created_time,modify_time from memo_group");

            //5. Return result set and process result
            while (resultSet.next()) {
                //If true is returned, there is the next record line, otherwise there is no record
                int id = resultSet.getInt("id");
                String name = resultSet.getString("name");
                LocalDateTime createTime = resultSet.getTimestamp("created_time").toLocalDateTime();
                LocalDateTime modifyTime=resultSet.getTimestamp("modify_time").toLocalDateTime();
                System.out.println(
                        String.format("Serial number:%d,Name:%s,Created:%s,Modified:%s",id,name,createTime.toString(),modifyTime.toString())
                );
            }


            //6. Close result set
            resultSet.close();

            //7. Close command
            statement.close();

            //8. Close connection
            connection.close();

        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}```

Tags: JDBC Database SQL Java

Posted on Fri, 06 Dec 2019 13:23:39 -0500 by snowdog