PreparedStatement를 활용한 성적 처리 프로그램 구현

ScoreDAO를 제외하고 변하는 부분은 없다

// <ScoreDAO.java>


package com.test;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

import com.util.DBConn;

public class ScoreDAO
{
	private Connection conn;
	
	public Connection connection() throws ClassNotFoundException, SQLException
	{
		conn = DBConn.getConnection();
		return conn;
	}
	
	
	// 성적 입력 메소드
	public int add(ScoreDTO dto) throws SQLException
	{
		
		int result = 0;
		
		String sql = "INSERT INTO TBL_SCORE(SID, NAME, KOR, ENG, MAT)"
				  + " VALUES(SCORESEQ.NEXTVAL, ?, ?, ?, ?)";
		
		PreparedStatement pstmt = conn.prepareStatement(sql);
		pstmt.setString(1, dto.getName());
		pstmt.setInt(2, dto.getKor());
		pstmt.setInt(3, dto.getEng());
		pstmt.setInt(4, dto.getMat());
		
		result = pstmt.executeUpdate();
		
		pstmt.close();
		
		return result;
	}
	
	
	// 전체 리스트 출력 메소드
	public ArrayList<ScoreDTO> lists() throws SQLException
	{
		ArrayList<ScoreDTO> result = new ArrayList<ScoreDTO>();
		
		String sql = "SELECT SID, NAME, KOR, ENG, MAT"
						+ ", (KOR + ENG + MAT) AS TOT"
						+ ", (KOR + ENG + MAT)/3 AS AVG"
						+ ", RANK() OVER(ORDER BY (KOR+ENG+MAT) DESC) AS RANK"
						+ " FROM TBL_SCORE"
						+ " ORDER BY SID ASC";
			
		PreparedStatement pstmt = conn.prepareStatement(sql);
		
		ResultSet rs = pstmt.executeQuery();
		
		while (rs.next())
		{
			ScoreDTO dto = new ScoreDTO();
			
			dto.setSid(rs.getString("SID"));
			dto.setName(rs.getString("NAME"));
			dto.setKor(rs.getInt("KOR"));
			dto.setEng(rs.getInt("ENG"));
			dto.setMat(rs.getInt("MAT"));
			dto.setTot(rs.getInt("TOT"));
			dto.setAvg(rs.getDouble("AVG"));
			dto.setRank(rs.getInt("RANK"));
			
			result.add(dto);
		}
		rs.close();
		pstmt.close();
		
		return result;
	}
	
	
	
	// 이름 검색 담당 메소드
	public ArrayList<ScoreDTO> lists(String name) throws SQLException
	{
		ArrayList<ScoreDTO> result = new ArrayList<ScoreDTO>();
		
		String sql = "SELECT SID, NAME, KOR, ENG, MAT, TOT, AVG, RANK"
				  + " FROM (SELECT SID, NAME, KOR, ENG, MAT, (KOR + ENG + MAT) AS TOT"
				  + ", (KOR + ENG + MAT)/3 AS AVG"
				  + ", RANK() OVER(ORDER BY (KOR+ENG+MAT) DESC) AS RANK"
				  + " FROM TBL_SCORE) WHERE NAME = ?";
		
		PreparedStatement pstmt = conn.prepareStatement(sql);
		
		pstmt.setString(1, name);
		
		ResultSet rs = pstmt.executeQuery();
		
		while (rs.next())
		{
			ScoreDTO dto = new ScoreDTO();
			
			dto.setSid(rs.getString("SID"));
			dto.setName(rs.getString("NAME"));
			dto.setKor(rs.getInt("KOR"));
			dto.setEng(rs.getInt("ENG"));
			dto.setMat(rs.getInt("MAT"));
			dto.setTot(rs.getInt("TOT"));
			dto.setAvg(rs.getDouble("AVG"));
			dto.setRank(rs.getInt("RANK"));
			
			result.add(dto);
			
		}
		rs.close();
		pstmt.close();
				
		
		return result;
	}
	
	
	// 번호 검색 메소드(수정 및 삭제를 하기 위해 식별하기 위해서..)
	public ArrayList<ScoreDTO> lists(int sid) throws SQLException
	{
		ArrayList<ScoreDTO> result = new ArrayList<ScoreDTO>();
		
		String sql = "SELECT SID, NAME, KOR, ENG, MAT, TOT, AVG, RANK"
						+ " FROM (SELECT SID, NAME, KOR, ENG, MAT"
						+ ", (KOR + ENG + MAT) AS TOT"
						+ ", (KOR + ENG + MAT)/3 AS AVG"
						+ ", RANK() OVER(ORDER BY (KOR+ENG+MAT) DESC) AS RANK"
						+ " FROM TBL_SCORE)"
						+ " WHERE SID = ?";
		
		PreparedStatement pstmt = conn.prepareStatement(sql);
		
		pstmt.setInt(1, sid);
		
		ResultSet rs = pstmt.executeQuery();
		
		while (rs.next())
		{
			ScoreDTO dto = new ScoreDTO();
			
			dto.setSid(rs.getString("SID"));
			dto.setName(rs.getString("NAME"));
			dto.setKor(rs.getInt("KOR"));
			dto.setEng(rs.getInt("ENG"));
			dto.setMat(rs.getInt("MAT"));
			dto.setTot(rs.getInt("TOT"));
			dto.setAvg(rs.getDouble("AVG"));
			dto.setRank(rs.getInt("RANK"));
			
			result.add(dto);
		}
		rs.close();
		pstmt.close();
				
		
		
		return result;
	}
	
	
	
	
	
	// 인원 수 확인 메소드
	public int count() throws SQLException
	{
		int result = 0;
		
		String sql = "SELECT COUNT(*) AS COUNT FROM TBL_SCORE";
		
		PreparedStatement pstmt = conn.prepareStatement(sql);
		
		ResultSet rs = pstmt.executeQuery();
		while (rs.next())
		{
			result = rs.getInt("COUNT");
		}
		rs.close();
		pstmt.close();
		
		return result;
	}
	
	
	
	
	// 데이터 수정 담당 메소드
	public int modify(ScoreDTO dto) throws SQLException
	{
		int result = 0;
		
		String sql = "UPDATE TBL_SCORE SET NAME= ?, KOR = ?, ENG = ?, MAT = ? WHERE SID = ?";
		
		PreparedStatement pstmt = conn.prepareStatement(sql);
		
		pstmt.setString(1, dto.getName());
		pstmt.setInt(2, dto.getKor());
		pstmt.setInt(3, dto.getEng());
		pstmt.setInt(4, dto.getMat());
		pstmt.setInt(5, Integer.parseInt(dto.getSid()));
		
		result = pstmt.executeUpdate();
		
		return result;
	}
	
	
	
	
	// 데이터 삭제 담당 메소드 
	public int remove(int sid) throws SQLException
	{
		int result = 0;
		
		String sql = "DELETE FROM TBL_SCORE WHERE SID = ?";
		
		PreparedStatement pstmt = conn.prepareStatement(sql);
		
		pstmt.setInt(1, sid);
		
		result = pstmt.executeUpdate();
		
		pstmt.close();
				
				
		
		return result;
	}


	public void close()
	{
		DBConn.close();
	}
	
}