07-prcmp.pc

《Oracle8i PL/SQL程序设计》附源码

/* 07-PRCMP.PC */
/* This file contains the Pro*C examples used in Chapter 7
   of "Oracle PL/SQL Programming".  These examples are Pro*C
   program fragments only - they are not complete programs. */

/* This is version 1.0 of this file, updated 2/18/96.
   Comments and questions should go to Scott Urman at
   [e-mail]. */

/* *** Chapter 7: Embedding a block *** */
EXEC SQL BEGIN DECLARE SECTION;
  /* Declare C variables. */
  VARCHAR v_Department[4]; /* The VARCHAR pseudo-type is
                              available only in Pro*C, and is
                              converted into a record type with
                              two fields - .arr and .len */
  int v_Course;            /* v_Course is an integer. */
  int v_StudentID;         /* So is v_StudentID. */
EXEC SQL END DECLARE SECTION;

  /* Initialize the host variables. Here we are just assigning
     to them, but they could be read from a file, accepted from 
     user input, etc. For the VARCHAR variables, the string is
     copied into the .arr field, and the length of the string (3
     in this case) is assigned to the .len field. */
  strcpy(v_Department.arr, "ECN");
  v_Department.len = 3;
  v_Course = 101;
  v_StudentID = 10006;

  /* Begin the embedded PL/SQL block. Note the EXEC SQL EXECUTE
     and END-EXEC; keywords, which delimit the block for the 
     precompiler. */
  EXEC SQL EXECUTE
    BEGIN
       Register(:v_Department, :v_Course, :v_StudentID);
    END;
  END-EXEC;

/* *** Chapter 7: Using Indicator Variables *** */
EXEC SQL BEGIN DECLARE SECTION;
  char v_Grade;    /* v_Grade is a single character. */
  short i_Grade;  /* Note that the indicator is declared as a
                     short, which is a 2 byte integer. */
EXEC SQL END DECLARE SECTION;

EXEC SQL EXECUTE
  BEGIN
    SELECT grade
      INTO :v_Grade INDICATOR :i_Grade
      FROM registered_students
      WHERE student_id = 10006
      AND department = 'ECN'
      AND course = 101;
  END;
END-EXEC;

  if (i_Grade != 0)
    printf("No grade recorded for this student\n");
  else
    printf("The grade recorded is %c\n", v_Grade);


/* *** Chapter 7: Pro*C Error Handling *** */
EXEC SQL INCLUDE SQLCA; /* This statement includes the SQLCA 
                           structure. This structure contains 
                           fields used for error handling. */
EXEC SQL EXECUTE
  BEGIN
    RecordFullClasses;
  END;
END-EXEC;
/* sqlca.sqlcode will be zero if the statement was successful,
   and will contain the error code if the statement completed
   with an error. If an error occurs, sqlca.sqlerrm.sqlerrmc
   will contain the error message text, and sqlca.sqlerrm.sqlerrml
   will contain the length of the message. */
if (sqlca.sqlcode != 0) {
  printf("Error during execution of RecordFullClasses.\n");
  printf("%.70s\n", sqlca.sqlerrm.sqlerrml, sqlca.sqlerrm.sqlerrmc);
  }
else
  printf("Execution successful.\n");