public class Demo1 {

    /**

     * 增加

     */

    @Test

    public void testInsert() {

       Connection conn = null;

       PreparedStatement stmt = null;

       try {

           //1.獲取連線

           conn = JdbcUtil.getConnection();

           //2.準備預編譯的sql

           String sql = "INSERT INTO student(NAME,gender) VALUES(?,?)"

           //3.執行預編譯sql語句(檢查語法)

           stmt = conn.prepareStatement(sql);

           //4.設定引數值

           /**

            * 引數一：引數位置從1開始

            */

           stmt.setString(1, "李四");

           stmt.setString(2, "男");

           //5.傳送引數，執行sql

           int count = stmt.executeUpdate();

           System.out.println("影響了"+count+"行");

       } catch (Exception e) {

           e.printStackTrace();

           throw new RuntimeException(e);

       } finally {

           JdbcUtil.close(conn, stmt);

       }

    }

    /**

     * 修改

     */

    @Test

    public void testUpdate() {

       Connection conn = null

       PreparedStatement stmt = null;

       try {

           //1.獲取連線

           conn = JdbcUtil.getConnection();

           //2.準備預編譯的sql

           String sql = "UPDATE student SET NAME=? WHERE id=?"; //?表示一個引數的佔位符

           //3.執行預編譯sql語句(檢查語法)

           stmt = conn.prepareStatement(sql);

           //4.設定引數值

           /**

            * 引數一：引數位置從1開始

            */

           stmt.setString(1, "王五");

           stmt.setInt(2, 9);

           //5.傳送引數，執行sql

           int count = stmt.executeUpdate();

           System.out.println("影響了"+count+"行");

       } catch (Exception e) {

           e.printStackTrace();

           throw new RuntimeException(e);

       } finally {

           JdbcUtil.close(conn, stmt);

       }

    }

    /**

     * 刪除

     */

    @Test

    public void testDelete() {

       Connection conn = null;

       PreparedStatement stmt = null;

       try {

           //1.獲取連線

           conn = JdbcUtil.getConnection();

           //2.準備預編譯的sql

           String sql = "DELETE FROM student WHERE id=?"; //?表示一個引數的佔位符

           //3.執行預編譯sql語句(檢查語法)

           stmt = conn.prepareStatement(sql);

           //4.設定引數值

           /**

            * 引數一：引數位置從1開始

            */

           stmt.setInt(1, 9);

           //5.傳送引數，執行sql

           int count = stmt.executeUpdate();

           System.out.println("影響了"+count+"行");

       } catch (Exception e) {

           e.printStackTrace();

           throw new RuntimeException(e);

       } finally {

           JdbcUtil.close(conn, stmt);

       }

    }

    /**

     * 查詢

     */

    @Test

    public void testQuery() {

       Connection conn = null;

       PreparedStatement stmt = null;

       ResultSet rs = null;

       try {

           //1.獲取連線

           conn = JdbcUtil.getConnection();

           //2.準備預編譯的sql

           String sql = "SELECT * FROM student";

           //3.預編譯

           stmt = conn.prepareStatement(sql);

           //4.執行sql

           rs = stmt.executeQuery();

           //5.遍歷rs

           while(rs.next()){

              int id = rs.getInt("id");

              String name = rs.getString("name");

              String gender = rs.getString("gender");

              System.out.println(id+","+name+","+gender);

           }

       } catch (Exception e) {

           e.printStackTrace();

           throw new RuntimeException(e);

       } finally {

           //關閉資源

           JdbcUtil.close(conn,stmt,rs);

       }

    }

}