Java_PreparedStatement

Java_PreparedStatement

 

PreparedStatement 개념 및 예제

 

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https://sas-study.tistory.com/160

[JDBC] PreparedStatement 개념 및 예제

 

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Scanner;

class DBConn{
	private static DBConn db;
	public static DBConn getInstance() {
		if(db==null) {
			db = new DBConn();
		}
		return db;
	}	
	public Connection getconn() {
		Connection con = null;
		try {
			Class.forName("org.mariadb.jdbc.Driver");
			String url = "jdbc:mariadb://220.70.33.29:3306/unknown";
			con = DriverManager.getConnection(url, "unknown", "01234567");
		} catch (Exception e) {
			e.printStackTrace();
			System.out.println("sql 접속오류");
		}
		return con;	
	}
}

public class Login {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		Connection conn = DBConn.getInstance().getconn();
		System.out.println("아이디를 입력하세요.");
		String id = sc.next();
		System.out.println("비밀번호를 입력하세요.");
		String pw = sc.next();
		
		String sql = "SELECT * FROM login WHERE id=? AND pw=?";
		
		//PreparedStatement
		PreparedStatement pstmt = null;
		try {
			pstmt = conn.prepareStatement(sql);
			//실제 sql에 데이터 붙이기
			pstmt.setString(1, id);	//물음표 위치에 어떤 값
			pstmt.setString(2, pw);	//적어주기 (위치, 값)
			// 실행
			ResultSet rs = pstmt.executeQuery();
			if(rs != null) {
				if(rs.next()) {
					System.out.println(rs.getString("name"));
				}
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}		
	}
}