jdbc——mysql的增、删、改、查测试

jdbc——mysql的增、删、改、查测试

工具：myeclipse
驱动包：https://dev.mysql.com/downloads/connector/j/5.1.html
加入驱动包后》》

准备数据库和表：

CREATE test IF NOT EXISTS user3 CHARACTER SET charset=utf8;

CREATE TABLE user3 ( id SMALLINT UNSIGNED AUTO_INCREMENT PRIMARY KEY, username VARCHAR(20) NOT NULL, password VARCHAR(32) NOT NULL, age TINYINT NOT NULL DEFAULT 18, sex BOOLEAN );

操做步骤：
1. 加载驱动程序
2. 得到数据库链接
3. 经过数据库链接操做数据库

---

如下是测试代码：
select.java

package mysql;

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

/** * jdbc链接mysql数据库 * 查询测试 * @author https://blog.csdn.net/qq_32953185/ */
public class select {

    static final String URL="jdbc:mysql://127.0.0.1:3306/test";
    static final String USER="root";
    static final String PASSWORD="admin";

    public static void main(String[] args) {

        try {
            //加载驱动程序
            Class.forName("com.mysql.jdbc.Driver");
            //得到数据库链接
            Connection conn = DriverManager.getConnection(URL,USER,PASSWORD);
            //经过数据库链接操做数据库
            Statement stmt = conn.createStatement();

            String sql = "select id,username,password,age,sex from user3;";
            ResultSet rs = stmt.executeQuery(sql);
            while(rs.next())
            {
                System.out.println(rs.getInt("id")+","+rs.getString("username")
                +","+rs.getString("password")+","+rs.getInt("age")+","+rs.getInt("sex"));
            }

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

}

测试结果：
输出了表的全部记录

insert.java

package mysql;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/** * jdbc链接mysql数据库 * 插入测试 * @author https://blog.csdn.net/qq_32953185/ */
public class insert {

    static final String URL="jdbc:mysql://127.0.0.1:3306/test";
    static final String USER="root";
    static final String PASSWORD="admin";

    public static void main(String[] args) {
        try {
            //加载驱动程序
            Class.forName("com.mysql.jdbc.Driver");
            //得到数据库链接
            Connection conn = DriverManager.getConnection(URL,USER,PASSWORD);
            //经过数据库链接操做数据库
            Statement stmt = conn.createStatement();

            String sql = "insert into user3 values("+"null,?,?,?,?)";
            PreparedStatement  ptmt = conn.prepareStatement(sql);

            //插入小明的记录
            ptmt.setString(1, "小明"); //id
            ptmt.setString(2, "12345"); //username
            ptmt.setInt(3, 20); //age
            ptmt.setInt(4, 1);  //sex
            ptmt.execute(); //执行
            System.out.println("执行完毕!");

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

    }
}

测试结果：
insert了一个小明的记录

update.java

package mysql;

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

/** * jdbc链接mysql数据库 * 更新测试 * @author https://blog.csdn.net/qq_32953185/ */
public class update {

    static final String URL="jdbc:mysql://127.0.0.1:3306/test";
    static final String USER="root";
    static final String PASSWORD="admin";

    public static void main(String[] args) {
        try {
            //加载驱动程序
            Class.forName("com.mysql.jdbc.Driver");
            //得到数据库链接
            Connection conn = DriverManager.getConnection(URL,USER,PASSWORD);
            //经过数据库链接操做数据库
            Statement stmt = conn.createStatement();

            String sql = " update user3 set username=?,password=?,age=?,sex=?"+
                         " where username=?";
            PreparedStatement  ptmt = conn.prepareStatement(sql);

            //把username为小明改为小日月
            ptmt.setString(1, "小日月"); //username
            ptmt.setString(2, "54321"); //password
            ptmt.setInt(3, 21); //age
            ptmt.setInt(4, 1);  //sex
            ptmt.setString(5, "小明");    //where username=小明
            ptmt.execute(); //执行
            System.out.println("执行完毕!");

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

    }
}

测试结果：
把小明的username修改为小日月

delete.java

package mysql;

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

/** * jdbc链接mysql数据库 * 删除测试 * @author https://blog.csdn.net/qq_32953185/ */
public class delete {
    static final String URL="jdbc:mysql://127.0.0.1:3306/test";
    static final String USER="root";
    static final String PASSWORD="admin";

    public static void main(String[] args) {
        try {
            //加载驱动程序
            Class.forName("com.mysql.jdbc.Driver");
            //得到数据库链接
            Connection conn = DriverManager.getConnection(URL,USER,PASSWORD);
            //经过数据库链接操做数据库
            Statement stmt = conn.createStatement();

            String sql = " delete from user3"+
                         " where username=?";
            PreparedStatement  ptmt = conn.prepareStatement(sql);

            //删除小日月的记录
            ptmt.setString(1, "小日月"); //name
            ptmt.execute(); //执行
            System.out.println("执行完毕!");

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

测试结果：
把小日月的记录删除了