我有一张这样的桌子:
CREATE TABLE book_info (
book_id VARCHAR(32) not null,
title varchar(255) not null,
author varchar(255) not null,
folder_path varchar(255) not null,
primary key(book_id)
);
我在上面插入了这些数据:
insert into book_info values('BOOK1', 'APUE', 'Richard Stevens', '/home/user1/unix_programming_books');
insert into book_info values('BOOK2', 'Unix Network programming', 'Richard Stevens', '/home/user1/unix_programming_books');
insert into book_info values('BOOK3', 'Core Python Applications Programming', 'Wesley J. Chun', '/home/user1/python_programming_books');
我正在尝试使用 Oracle PRO*C 更新此表,但我不能!下面是我的代码:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
EXEC SQL INCLUDE SQLCA;
EXEC SQL INCLUDE ORACA;
#define USER_LEN 10
#define PASS_LEN 10
VARCHAR user[USER_LEN];
VARCHAR pass[PASS_LEN];
#define STRCPY_TO_ORA(dest, source)\
dest.len = strlen(source);\
strcpy((char *)dest.arr, (const char *)source)
#define STRCPY_FROM_ORA(dest, source)\
source.arr[source.len] = 0;\
strcpy((char *)dest,(const char *)source.arr)
/* Connecting to the database */
int db_connection(char *db_user, char *db_pass)
{
strncpy((char *) user.arr, db_user, USER_LEN);
user.len = strlen((char *) user.arr);
strncpy((char *) pass.arr, db_pass, PASS_LEN);
pass.len = strlen((char *) pass.arr);
EXEC SQL CONNECT :user IDENTIFIED BY :pass;
if (sqlca.sqlcode != 0)
{
fprintf(stdout, "Connection failed:%s\n", sqlca.sqlerrm.sqlerrmc);
return(sqlca.sqlcode);
}
fprintf(stdout, "Connected to ORACLE as user:%s\n", user.arr);
return (sqlca.sqlcode);
}
int book_not_found_function(char *path)
{
fprintf(stdout, "%s\n", __FUNCTION__);
}
int path_update_success_function(char *book_id, char *new_path)
{
fprintf(stdout, "Update book %s path to %s\n", book_id, new_path);
}
void other_function(void)
{
fprintf(stdout, "%s\n", __FUNCTION__);
}
/* Updating books path */
int books_path_updating(char *old_path, char *new_path)
{
char book_id_string[32];
EXEC SQL BEGIN DECLARE SECTION;
varchar sql_old_path[255];
varchar sql_new_path[255];
varchar sql_book_id[32];
EXEC SQL END DECLARE SECTION;
STRCPY_TO_ORA(sql_old_path, old_path);
STRCPY_TO_ORA(sql_new_path, new_path);
/* Declare a cursor for the FETCH statement. */
EXEC SQL DECLARE books_cursor CURSOR FOR
SELECT BOOK_ID
FROM BOOK_INFO
WHERE FOLDER_PATH = :sql_old_path;
if (sqlca.sqlcode != 0)
{
fprintf(stdout, "Declare cursor failed\n");
fprintf(stdout, "Oracle error %s\n", sqlca.sqlerrm.sqlerrmc);
return(sqlca.sqlcode);
}
EXEC SQL OPEN books_cursor;
if (sqlca.sqlcode != 0)
{
fprintf(stdout, "Open cursor failed\n");
fprintf(stdout, "Oracle error %s\n", sqlca.sqlerrm.sqlerrmc);
return(sqlca.sqlcode);
}
for ( ;; )
{
//EXEC SQL WHENEVER NOT FOUND DO break; // I used it but still nothing
//EXEC SQL WHENEVER NOT FOUND GOTO not_found; // I used this too
//EXEC SQL WHENEVER NOT FOUND DO continue; // I used this too
/* Fetching data */
EXEC SQL FETCH books_cursor
INTO :sql_book_id;
if (sqlca.sqlcode == 1403)
{
fprintf(stdout, "No book found for this folder %s\n", old_path);
book_not_found_function(old_path);
return 0;
}
else if (sqlca.sqlcode != 0)
{
fprintf(stdout, "Oracle error %s\n", sqlca.sqlerrm.sqlerrmc);
EXEC SQL CLOSE books_cursor;
return (sqlca.sqlcode);
}
else
{
STRCPY_FROM_ORA(book_id_string, sql_book_id);
fprintf(stdout, "BOOK_ID = %s\n", book_id_string);
/* Updating the path */
EXEC SQL UPDATE BOOK_INFO
SET FOLDER_PATH =:sql_new_path
WHERE BOOK_ID =:sql_book_id;
if (sqlca.sqlcode != 0)
{
fprintf(stdout, "Oracle error %s\n", sqlca.sqlerrm.sqlerrmc);
EXEC SQL CLOSE books_cursor;
return (sqlca.sqlcode);
}
else
{
path_update_success_function(book_id_string, new_path);
}
}
}
EXEC SQL CLOSE books_cursor;
other_function();
EXEC SQL COMMIT WORK RELEASE;
return 0;
}
int main(int argc, char **argv)
{
db_connection("evariste", "123456");
books_path_updating("/home/user1/unix_programming_books", "/home/user1/UNIX_PROGRAMMING_BOOKS");
books_path_updating("/non_existing_path", "/non_existing_path");
return 0;
}
该程序产生输出:
Connected to ORACLE as user:evariste
BOOK_ID = BOOK1
Update book BOOK1 path to /home/user1/UNIX_PROGRAMMING_BOOKS
BOOK_ID = BOOK2
Update book BOOK2 path to /home/user1/UNIX_PROGRAMMING_BOOKS
No book found for this folder /home/user1/unix_programming_books // WHEY THIS?
book_not_found_function // WHY THIS
Declare cursor failed // WHY THIS
Oracle error ORA-01403: no data found // WHY THIS
该表没有更新,函数path_update_success_function和other_function永远不会执行!为什么这个?
谢谢你的帮助。