how to compare value from database reading

[ichoel]

Hi CVI Expert, 

I want to find if serial number that i input has already been exist on database or not. I use sql toolkit. My database is MS Access.

Here the code that i tried :

hdbc = DBConnect (connectString);

if (hdbc <= 0) {ShowError(); goto Error;}

hmap = DBBeginMap(hdbc);

if (hmap<=0) {ShowError(); goto Error;} 

resCode = DBMapColumnToChar (hmap, TraceSerial16, 17, uutNum, uutStat, "");

if (resCode != DB_SUCCESS) {ShowError(); goto Error;}

hstmt = DBActivateMap(hmap,"CounterTable_Control");

if (hstmt==0)  {ShowError(); goto Error;}

while ((resCode = DBFetchNext (hstmt)) == DB_SUCCESS) {

if (uutNum=="8003050013031014"){

statusSN = 1;

break;

}

else

statusSN = 0;

printf("Serial Number %s \n",uutNum);

}

if (statusSN==1){

MessagePopup("Status","OK");

resCode = DBDeactivateMap(hmap);

if ((resCode != DB_SUCCESS)) {ShowError(); goto Error;} 

resCode = DBDeactivateSQL (hstmt);

if (resCode != DB_SUCCESS) {ShowError(); goto Error;}

resCode = DBDisconnect (hdbc);

if (resCode != DB_SUCCESS) {ShowError(); goto Error;}

My problem is, the comparison nevers succeed (red text). Can you help me why ?

Regards,

[Wolfgang]

Comparing strings works differently. You should use strcmp(string_1, string_2)

[Al_S]

Yeah, as Wolfgang said, use the ANSI C string compare library function.  Look at the help for the strcmp() function.  It returns 0 if the strings match.

In ANSI C,

if (uutNum=="8003050013031014")

acutally compares the pointers to the strings, not the string content.  That's why you never saw a match.

[ichoel]

Thank you guys. It works well.