我不确定有什么问题“参数编号 2 不是 OUT 参数”

Question

 try{
            Class.forName("com.mysql.jdbc.Driver");
            mycon = DriverManager.getConnection("jdbc:mysql://localhost:3306/schoolDb?autoReconnect=true&useSSL=false", "root", "Banita");
            CallableStatement cs = mycon.prepareCall("{call showData(?, ?, ?)}");


            cs.setInt(1, 20);
            cs.registerOutParameter(2, Types.INTEGER);
            cs.registerOutParameter(3, Types.CHAR);

            cs.executeUpdate();

        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }

Did i do something on create procedure parameter here ?

CREATE DEFINER=`root`@`localhost` PROCEDURE `showData`(in id int, out deptNO int, out LOC char(12))
BEGIN
    select DEPTNO, LOC INTO deptNO, LOC from schooolDb.UDP_DEPT_DNAME where deptNO = id;
END

Answer 1

Try

CREATE DEFINER=`root`@`localhost` PROCEDURE `showData`(in id int, out o_deptno int, out o_loc char(12))
BEGIN
  select DEPTNO, LOC INTO o_deptno, o_loc from schooolDb.UDP_DEPT_DNAME where DEPTNO = id;
END