JDBC DML(insert, update, delete)

Connection conn = null;

Statement stmt = null;

conn = DriverManager.getConnection("~")

stmt = conn.createStatement();

 

INSERT

String sql = "insert into dmlemp(empno, ename, deptno)";

sql+= "valuessql+= " values(" +empno+",'" + ename + "'," + deptno+ ")";

stmt.executeUpdate(sql);

 

UPDATE

String sql = "update dmlemp set sal=0 where deptno="+deptno;

stmt.executeUpdate(sql);

 

DELETE

String sql = "delete from dmlemp where deptno="+deptno;

stmt.executeUpdate(sql);

 

	Connection conn = null;
  	Statement stmt = null;
  	//ResultSet (x) >> DML
  	
  	try{
  		Class.forName("oracle.jdbc.OracleDriver");
  		conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","사용자이름","암호");
		System.out.println("연결 여부 : false :" + conn.isClosed());
		
		stmt = conn.createStatement();
		/*
		//INSERT
		int empno=0;
		String ename="";
		int deptno=0;
		
		Scanner sc = new Scanner(System.in);
		System.out.println("사번 입력");
		empno = Integer.parseInt(sc.nextLine());
		
		System.out.println("이름 입력");
		ename = sc.nextLine();
		
		System.out.println("부서번호 입력");
		deptno = Integer.parseInt(sc.nextLine());
		
		//insert into emp(empno,ename,deptno) values(2000,'홍길동',30)
		//조선시대나 .... 현대 (parameter  설정 ...) >> values(?,?,?)
		String sql="insert into dmlemp(empno,ename,deptno) ";
		sql+= " values(" +empno+",'" + ename + "'," + deptno+ ")";
  		 
		int resultrow = stmt.executeUpdate(sql);
		
		*/
		//UPDATE
		/* 
		int deptno = 20;
		String sql = "update dmlemp set sal=0 where deptno=" + deptno;
		 */
		 
		//DELETE
		int deptno = 20;
		String sql = "delete from dmlemp where deptno=" + deptno;
		 
		int resultrow = stmt.executeUpdate(sql);
		
		if(resultrow > 0){
			System.out.println("반영된 행의 수 : " + resultrow);
		}else{
			//POINT
			//문제가 생긴것이 아니고(예외가 발생된 것이 아니라)
			//반영된 행이 없다
			System.out.println("반영된 행이 없다 ...");
		}
	   	
  	}catch(Exception e){
  		   System.out.println(e.getMessage());
  		   //여기서 코드 처리
  	}finally{
 		if(stmt != null)try {stmt.close();}catch (Exception e) {}
		if(conn != null)try {conn.close();}catch (Exception e) {}
  	}