Oracle存储过程JDBC调用命名参数失败，出现 "Found Symbol >

Question

我得到了这个Oracle存储过程的代码，调用另一个存储过程，现在我的任务是用Java调用xyz_main。

PROCEDURE xyz_main (
  i_param_a IN VARCHAR2 DEFAULT 'Y',
  i_param_b IN PERSON.NAME%TYPE
  i_param_c IN VARCHAR2 DEFAULT 'BLA'
  o_return_msg OUT VARCHAR2
)
IS
  ...
BEGIN
  ...
END xyz_main;

PROCEDURE xyz_example (
  i_param_b IN PERSON.NAME%TYPE DEFAULT 'Ben'
  o_return_msg OUT VARCHAR2
)
IS
BEGIN
  xyz_main(
    i_param_b => i_param_b,
    i_param_c => 'Great',
    o_return_msg => o_return_msg
  );
END xyz_example;

现在我的任务是用Java调用xyz_main。我写了这段代码。

// Using question mark because later on the values will be provided by function parameters
// Question: is "o_return_msg => ?" correct, even if I don't provide an input value?
String statement = "BEGIN xyz_main(i_param_b => ?, i_param_c => ?, o_return_msg => ?); END;";  

try (Connection conn = getOraConnection();) {
  CallableStatement cs = conn.prepareCall(statement);

  // cs.setString("i_param_a", "Y"); -- omitted because the default value should be used always
  cs.setString("i_param_b", "Ben");
  cs.setString("i_param_c", "Great"); // should overwrite the default value
  cs.registerOutParameter("o_return_msg", Types.VARCHAR);

  cs.execute();
} catch (Exception e) {
  ...
}

运行这段代码，我得到了这个Exception:

ORA-06550: line 1, column 47:
PLS-00103: Fand das Symbol ">" als eines der folgenden erwartet wurde: .. 

在英语中:

PLS-00103: Found Symbol ">" but expected one of this: ..

这段代码有什么问题？

Answer 1

我以为在使用命名参数时，总是要使用'par_name => ? 这是错误的。

写这样的代码是没有问题的。

//* don't work:
// String statement = "BEGIN xyz_main(i_param_b => ?, i_param_c => ?, o_return_msg => ?); END;";  // don't work
//* works:
String statement = "BEGIN xyz_main(?, ?, ?); END;"; 

try (Connection conn = getOraConnection();) {
  CallableStatement cs = conn.prepareCall(statement);
  // cs.setString("i_param_a", "Y"); -- omitted because the default value should be used always
  cs.setString("i_param_b", "Ben");
  cs.setString("i_param_c", "Great"); // should overwrite the default value
  cs.registerOutParameter("o_return_msg", Types.VARCHAR);
  cs.execute();
  System.out.println(cs.getString("o_return_msg"));
  cs.close();
} catch (Exception e) {
  ...
}