PL/SQL存储过程调用报错：Identifier must be declared问题求助

Let's walk through the most common reasons you're hitting this error and how to fix them:

• Incorrect procedure name or missing schema qualifier
  If you're calling the procedure from a different user/schema than the one it was created in, you need to include the schema name when invoking it. For example, if you created add_student under the STUDENT_ADMIN schema, call it like this:

  BEGIN
    STUDENT_ADMIN.add_student(123, 'Alice', 'Smith', 'Enrolled', 3.9, 'alice.s@school.edu');
  END;
  /
  

  Also double-check for typos in the procedure name—even a single wrong character will trigger this error.

• Missing EXECUTE permission
  The user you're using to call the procedure might not have been granted the right to execute it. Run this as the procedure's owner to fix that:

  GRANT EXECUTE ON add_student TO your_calling_user;
  

• Invalid call syntax
  If you're using SQL*Plus or a similar tool, you can't just type the procedure name directly. Use either the EXEC shortcut or wrap it in a PL/SQL block:

  • Using EXEC:

    EXEC add_student(123, 'Alice', 'Smith', 'Enrolled', 3.9, 'alice.s@school.edu');
    

  • Using a PL/SQL block:

    BEGIN
      add_student(123, 'Alice', 'Smith', 'Enrolled', 3.9, 'alice.s@school.edu');
    END;
    /
    

• Procedure not actually created successfully (hidden errors)
  Sometimes even if you see a "Procedure created" message, there might be underlying issues (like the STUDENTS table not existing in the schema at creation time). Verify the procedure exists by querying the data dictionary:

  SELECT object_name, status FROM user_objects WHERE object_name = 'ADD_STUDENT';
  

  If the status isn't VALID, recompile the procedure with:

  ALTER PROCEDURE add_student COMPILE;
  

内容的提问来源于stack exchange，提问作者935