java13_JDBC

JDBC连接数据库操作：

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1. 增加操作：

Copy Codeimport java.sql.*;

public class Main {
    public static void main(String[] args) {
        try {
            // 加载数据库驱动程序
            Class.forName("com.mysql.jdbc.Driver");

            // 获取连接对象
            String url = "jdbc:mysql://localhost:3306/ZWM";
            String user = "root";
            String password = "root";
            Connection conn = DriverManager.getConnection(url, user, password);

            // 创建 Statement 对象
            Statement stmt = conn.createStatement();

            // 执行 SQL 语句
            String sql = "INSERT INTO t_student(no, name, age) VALUES('001', '张三', '18')";
            int result = stmt.executeUpdate(sql);
            if (result > 0) {
                System.out.println("添加成功！");
            } else {
                System.out.println("添加失败！");
            }

            // 关闭对象
            stmt.close();
            conn.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

2. 删除操作：

Copy Codeimport java.sql.*;

public class Main {
    public static void main(String[] args) {
        try {
            // 加载数据库驱动程序
            Class.forName("com.mysql.jdbc.Driver");

            // 获取连接对象
            String url = "jdbc:mysql://localhost:3306/ZWM";
            String user = "root";
            String password = "root";
            Connection conn = DriverManager.getConnection(url, user, password);

            // 创建 Statement 对象
            Statement stmt = conn.createStatement();

            // 执行 SQL 语句
            String sql = "DELETE FROM t_student WHERE no = '001'";
            int result = stmt.executeUpdate(sql);
            if (result > 0) {
                System.out.println("删除成功！");
            } else {
                System.out.println("删除失败！");
            }

            // 关闭对象
            stmt.close();
            conn.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

3. 修改操作：

Copy Codeimport java.sql.*;

public class Main {
    public static void main(String[] args) {
        try {
            // 加载数据库驱动程序
            Class.forName("com.mysql.jdbc.Driver");

            // 获取连接对象
            String url = "jdbc:mysql://localhost:3306/ZWM";
            String user = "root";
            String password = "root";
            Connection conn = DriverManager.getConnection(url, user, password);

            // 创建 Statement 对象
            Statement stmt = conn.createStatement();

            // 执行 SQL 语句
            String sql = "UPDATE t_student SET name = '李四', age = '20' WHERE no = '002'";
            int result = stmt.executeUpdate(sql);
            if (result > 0) {
                System.out.println("修改成功！");
            } else {
                System.out.println("修改失败！");
            }

            // 关闭对象
            stmt.close();
            conn.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

4. 查询操作：

Copy Codeimport java.sql.*;

public class Main {
    public static void main(String[] args) {
        try {
            // 加载数据库驱动程序
            Class.forName("com.mysql.jdbc.Driver");

            // 获取连接对象
            String url = "jdbc:mysql://localhost:3306/ZWM";
            String user = "root";
            String password = "root";
            Connection conn = DriverManager.getConnection(url, user, password);

            // 创建 Statement 对象
            Statement stmt = conn.createStatement();

            // 执行 SQL 语句
            String sql = "SELECT * FROM t_student";
            ResultSet rs = stmt.executeQuery(sql);

            // 处理结果集
            while (rs.next()) {
                String no = rs.getString("no");
                String name = rs.getString("name");
                int age = rs.getInt("age");
                System.out.println(no + "\t" + name + "\t" + age);
            }

            // 关闭对象
            rs.close();
            stmt.close();
            conn.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}