idea连接mysql数据库进行增删改查

首先需要在项目中引入 mysql-connector-java 的依赖，然后在代码中进行数据库的连接和操作，下面是一个简单的示例：

1. 连接数据库

import java.sql.*;

public class DBUtil {
    private static final String URL = "jdbc:mysql://localhost:3306/test?useSSL=false&serverTimezone=UTC&allowPublicKeyRetrieval=true";
    private static final String USER = "root";
    private static final String PASSWORD = "123456";

    public static Connection getConnection() {
        Connection conn = null;
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            conn = DriverManager.getConnection(URL, USER, PASSWORD);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
}

2. 插入数据

public class InsertDemo {
    public static void main(String[] args) {
        Connection conn = null;
        PreparedStatement pstmt = null;
        try {
            conn = DBUtil.getConnection();
            String sql = "INSERT INTO student(name, age, sex) VALUES (?, ?, ?)";
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, "张三");
            pstmt.setInt(2, 20);
            pstmt.setString(3, "男");
            int result = pstmt.executeUpdate();
            if (result > 0) {
                System.out.println("插入成功！");
            } else {
                System.out.println("插入失败！");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(conn, pstmt, null);
        }
    }
}

3. 更新数据

public class UpdateDemo {
    public static void main(String[] args) {
        Connection conn = null;
        PreparedStatement pstmt = null;
        try {
            conn = DBUtil.getConnection();
            String sql = "UPDATE student SET age = ? WHERE name = ?";
            pstmt = conn.prepareStatement(sql);
            pstmt.setInt(1, 21);
            pstmt.setString(2, "张三");
            int result = pstmt.executeUpdate();
            if (result > 0) {
                System.out.println("更新成功！");
            } else {
                System.out.println("更新失败！");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(conn, pstmt, null);
        }
    }
}

4. 查询数据

public class QueryDemo {
    public static void main(String[] args) {
        Connection conn = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        try {
            conn = DBUtil.getConnection();
            String sql = "SELECT * FROM student WHERE name = ?";
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, "张三");
            rs = pstmt.executeQuery();
            while (rs.next()) {
                System.out.println("姓名：" + rs.getString("name"));
                System.out.println("年龄：" + rs.getInt("age"));
                System.out.println("性别：" + rs.getString("sex"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(conn, pstmt, rs);
        }
    }
}

需要注意的是，一定要在使用完数据库连接等资源后进行关闭，否则会出现资源泄漏问题。在上述示例中，我们使用了一个工具类 DBUtil 来进行资源的关闭操作。