Android studio连接mysql，点击button按钮后对mysql里面的数据进行增删查改的具体代码

在Android Studio连接MySQL数据库的方式有很多，这里提供一种基于 JDBC 连接 MySQL 数据库的方法。以下是一个示例代码，实现了点击按钮后对 MySQL 数据库中的数据进行增删查改操作：

public class MainActivity extends AppCompatActivity {
    private static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    private static final String DB_URL = "jdbc:mysql://localhost:3306/test";
    private static final String USER = "root";
    private static final String PASS = "password";

    private Connection conn = null;
    private Statement stmt = null;

    private EditText editName;
    private EditText editAge;
    private Button btnAdd;
    private Button btnDelete;
    private Button btnUpdate;
    private Button btnQuery;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        editName = findViewById(R.id.edit_name);
        editAge = findViewById(R.id.edit_age);
        btnAdd = findViewById(R.id.btn_add);
        btnDelete = findViewById(R.id.btn_delete);
        btnUpdate = findViewById(R.id.btn_update);
        btnQuery = findViewById(R.id.btn_query);

        // 注册 JDBC 驱动
        try {
            Class.forName(JDBC_DRIVER);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

        // 打开连接
        try {
            conn = DriverManager.getConnection(DB_URL, USER, PASS);
        } catch (SQLException e) {
            e.printStackTrace();
        }

        // 按钮点击事件
        btnAdd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String name = editName.getText().toString();
                int age = Integer.parseInt(editAge.getText().toString());
                addData(name, age);
            }
        });

        btnDelete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String name = editName.getText().toString();
                deleteData(name);
            }
        });

        btnUpdate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String name = editName.getText().toString();
                int age = Integer.parseInt(editAge.getText().toString());
                updateData(name, age);
            }
        });

        btnQuery.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                queryData();
            }
        });
    }

    // 添加数据
    private void addData(String name, int age) {
        try {
            stmt = conn.createStatement();
            String sql = "INSERT INTO student (name, age) VALUES ('" + name + "', " + age + ")";
            stmt.executeUpdate(sql);
            Toast.makeText(this, "添加成功", Toast.LENGTH_SHORT).show();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    // 删除数据
    private void deleteData(String name) {
        try {
            stmt = conn.createStatement();
            String sql = "DELETE FROM student WHERE name = '" + name + "'";
            stmt.executeUpdate(sql);
            Toast.makeText(this, "删除成功", Toast.LENGTH_SHORT).show();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    // 更新数据
    private void updateData(String name, int age) {
        try {
            stmt = conn.createStatement();
            String sql = "UPDATE student SET age = " + age + " WHERE name = '" + name + "'";
            stmt.executeUpdate(sql);
            Toast.makeText(this, "更新成功", Toast.LENGTH_SHORT).show();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    // 查询数据
    private void queryData() {
        try {
            stmt = conn.createStatement();
            String sql = "SELECT * FROM student";
            ResultSet rs = stmt.executeQuery(sql);

            StringBuilder sb = new StringBuilder();
            while (rs.next()) {
                String name = rs.getString("name");
                int age = rs.getInt("age");
                sb.append("姓名: ").append(name).append(", 年龄: ").append(age).append("\n");
            }
            Toast.makeText(this, sb.toString(), Toast.LENGTH_SHORT).show();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    // 关闭连接
    @Override
    protected void onDestroy() {
        super.onDestroy();
        try {
            if (stmt != null) {
                stmt.close();
            }
            if (conn != null) {
                conn.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

以上示例代码中，我们实现了对名为 test 的 MySQL 数据库中的 student 表进行增删查改操作。你需要根据自己的实际情况修改代码中的数据库连接信息和表名。