[JDBC] 자바와 데이터 베이스(Oracle SQL) 연결하기

STATEMENT

 

package jdbc;
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;
 
public class JDBCOracleStatementTest {
 
	public static void main(String[] args) {
		Scanner sc= new Scanner(System.in);
		Connection conn = null;
		
		try {
			// 1. 드라이버 로드
			Class.forName("oracle.jdbc.driver.OracleDriver");
			System.out.println("Oracle Driver Load !!!");
			
			// 2. DB 연결     localhost == 127.0.0.1
			String jdbcUrl = "jdbc:oracle:thin:@localhost:1521:orcl";
			String user = "scott";
			String password = "tiger";
			
			conn = DriverManager.getConnection(jdbcUrl, user, password);
			System.out.println("데이터베이스에 접속했습니다.");
			
			// 3. statement 인스턴스생성
			
			Statement stmt = conn.createStatement();
			
			System.out.println("부서 이름을 입력해주세요.");
			String userDname= sc.nextLine();
			System.out.println("부서의 위치를 입력해주세요.");
			String userLoc = sc.nextLine();
			
			
			// 입력 : insert
			
			String sqlInsert = "insert into dept values (SEQ_DEPT_DEPTNO.NEXTVAL,'"+userDname+"','"+userLoc+"')";
				
			
			int resultCnt = stmt.executeUpdate(sqlInsert); // sql문을 실행하고 횟수반환
			if(resultCnt>0) {
				System.out.println("정상적인 입력");
			}
			
			// 4. sql 실행 : 부서리스트 출력
			String sql="select * from dept order by deptno";
			ResultSet rs = stmt.executeQuery(sql);
			
			// 5. ResultSet을 이용해서 결과 출력
			while(rs.next()) { 			// rs.next(); // boolean Type
				int deptno = rs.getInt("deptno");
				String dname = rs.getString("dname");
				String loc = rs.getString(3);
				System.out.println(deptno+", "+ dname+ ", "+loc);
				
			}
			
			rs.close();
			stmt.close();
			conn.close();		
			
		} catch (ClassNotFoundException e) {
			System.out.println("Driver 로드 실패");
			
		} catch (SQLException e) {
			e.printStackTrace();
		}
		
		
		 
		
		
		
	}
 
}

 

 

PREPAREDSTATEMENT

 

package jdbc;
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Scanner;
 
public class JDBCOraclePreparedTest {
 
	public static void main(String[] args) {
		Scanner sc= new Scanner(System.in);
		Connection conn = null;
		
		try {
			// 1. 드라이버 로드
			Class.forName("oracle.jdbc.driver.OracleDriver");
			System.out.println("Oracle Driver Load !!!");
			
			// 2. DB 연결     localhost == 127.0.0.1
			String jdbcUrl = "jdbc:oracle:thin:@localhost:1521:orcl";
			String user = "scott";
			String password = "tiger";
			
			conn = DriverManager.getConnection(jdbcUrl, user, password);
			System.out.println("데이터베이스에 접속했습니다.");
			
		
			//Statement stmt = conn.createStatement();
			
			System.out.println("부서 이름을 입력해주세요.");
			String userDname= sc.nextLine();
			System.out.println("부서의 위치를 입력해주세요.");
			String userLoc = sc.nextLine();
			
			
			// PreparedStatement 인스턴스 생성
			String sqlInsert = "insert into dept values (Seq_dept_deptno.nextval, ?, ?)";
			
			PreparedStatement pstmt = conn.prepareStatement(sqlInsert);
			pstmt.setString(1, userDname);
			pstmt.setString(2, userLoc);
			
			int resultCnt = pstmt.executeUpdate();
			
			if(resultCnt>0) {
				System.out.println("정상적으로 입력되었음.");
			}else {
				System.out.println("데이터 입력이 되지 않았음.");
			}
			
			// 부서 리스트 출력
			String sqlList ="select * from dept order by loc";
			pstmt = conn.prepareStatement(sqlList);
			ResultSet rs = pstmt.executeQuery();
			
			while(rs.next()) {
				System.out.print(rs.getInt(1)+", ");
				System.out.print(rs.getString(2)+", ");
				System.out.print(rs.getString(3)+"\n");
			}
			
			rs.close();
			pstmt.close();
			conn.close();
			
		} catch (ClassNotFoundException e) {
			System.out.println("Driver 로드 실패");
			
		} catch (SQLException e) {
			e.printStackTrace();
		}
		
		
		 
		
		
		
	}
 
}

 

 

PREPAREDSTATEMENT 2) 검색

 

package jdbc;
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;
 
public class JDBCOraclePreparedTest2 {
 
   public static void main(String[] args) {
 
      Scanner sc = new Scanner(System.in);
      
      Connection conn = null;
      
      try {
         // 1. 드라이버 로드
         Class.forName("oracle.jdbc.driver.OracleDriver");
         System.out.println("Oracle Driver Load!");
         
         // 2. DB 연결       localhost == 127.0.0.1
         String jdbcUrl ="jdbc:oracle:thin:@localhost:1521:orcl";
         String user = "scott";
         String password = "tiger";
         
         conn = DriverManager.getConnection(jdbcUrl, user, password);
         System.out.println("데이터베이스에 접속했습니다.");
         
         
         // 3. statement 인스턴스생성
         PreparedStatement pstmt = null;
 
         
         System.out.println("검색하고 싶은 부서 이름을 입력하세요.");
         String searchDname = sc.nextLine();
         
         // 부서 정보 리스트 
         String sqlSelect = "select * from dept where dname=? order by loc";
         
         pstmt = conn.prepareStatement(sqlSelect);
         pstmt.setString(1, searchDname);
         
         ResultSet rs = pstmt.executeQuery();
         
         if(!rs.next()) {
            System.out.println("검색 결과 X");
         } else {
            do  {
               System.out.print(rs.getInt(1)+"\t");
               System.out.print(rs.getNString(2)+"\t");
               System.out.print(rs.getNString(3)+"\n");
            } while(rs.next());
         }
         
         
         rs.close();
         pstmt.close();
         conn.close();
         
         
         
      } catch (ClassNotFoundException e) {
         System.out.println("Driver 로드 실패");
      } catch (SQLException e) {
         e.printStackTrace();
      }
      
      
      
      
      
   }
 
}