[問題] 字串過長導致mysql query語句失敗

[leepair (leepair)]

開發平台(Platform): (Ex: VC++, GCC, Linux, ...)  linux

額外使用到的函數庫(Library Used): (Ex: OpenGL, ...)  no

問題(Question)：
     各位版大午安，C新手遇到query語句內容過長被切斷導致失敗，請問
  Char* str = mallco(max)會有最大長度限制嗎?因為宣告的matchList超過一定長度
  後會變"...", 如下:
  "8731566,3936716,8130337,3354438,2053144,2851501,6844897,5783871,
  5955828,7111137,4619358,5153177,8982397,5722294,9477904,9621609,5946231,
  3959745,5844175,1853635,9266298,2098142,7880399,5827968,2090412,7400260,
  5673557,7441594,8688008,4716395,4325968,8119113,3204530,2471006,7910962,..."
  query的語句的最後也變成"...", 被切掉變成不完整的語句，如下:
  "INSERT INTO userTable (`userNo`, `matchList`, `matchCount`) values(
  '1016807', '3650073,4943658,2108930,3211272,3027544,9850878,1777923,1237709,
  5564440,9438165,3484492,3243042,7807987,4522503,2282327,8531729,5378840,
  9542612,6544303,8833169,5817709,1097157,9129560,7570933,9493099,1280278,
  3351816..."
      請問是我的char*宣告的不夠長嗎? 還是超過了限制? 請大大們指導一下，感恩。


  程式碼:
  for (int i = 0; i < UserAmount; i++) {
    int userNo = get_random_number(1000000, 9999999);
    char userNoStr[128];
    snprintf(userNoStr, 128, "%d", userNo);
    printf("user no: %s\n", userNoStr);

    int matchCount = get_random_number(10, 1000);
    int matchlength = matchCount * (int)(strlen(userNoStr) + 1) * sizeof(char);
    char* matchList = malloc(matchCharLength);
    for (int j = 0; j < matchCount; j++) {
      char matchUserNo[256];
      if (strlen(matchList) == 0) {
        snprintf(matchUserNo, 256, "%d", get_random_number(1000000, 9999999));
      }
      else{
        snprintf(matchUserNo, 256, ",%d", get_random_number(1000000, 9999999));
      }
        strcat(matchList, matchUserNo);
    }

    int queryCharLength = (int)strlen(matchList) + 128;
    char* sqlInsertUserNo = malloc(queryCharLength);
    snprintf(sqlInsertUserNo, queryCharLength, "INSERT INTO userTable (`userNo
      `, `matchList`, `matchCount`) values('%d', '%s', '%d') ON DUPLICATE KEY
      UPDATE `userNo` = '%d'", userNo, matchList, matchCount, userNo);

    int queryFail = mysql_query(mysqlConnection, sqlInsertUserNo);
    if (queryFail) {
       printf("Error query: %s\n", sqlInsertUserNo);
       printf("Error %s\n", mysql_error(mysqlConnection));
       mysql_close(mysqlConnection);
       exit(0);
    }
   }

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推 q82419: malloc出來記得要先memset
推 q82419: 你的malloc吃的應該是matchlength吧？
→ q82419: malloc吃的是size_t  出來的東西要轉char*不然會有warning
推 q82419: 看起來很像是C字串結尾沒有補'\0'的關係
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→ MOONRAKER: SUPER BIG
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