Pb retrieving sorted data from Table in SQL.

Question

Hi,
I get problem to retrieve data in the right order from table in database SQL.
See code attached: code.png
I want to sort data according to ID number And then to retrieve those data and fill out a ring control in the right order "descending" .
But i got always ID 2 instead of 1. See attached  picture : control.png
it seems that the select statement (see under) is not woking properly. But it is working well in a query in Access DataBase .  
//Select statement
   hstmt = DBActivateSQL (hdbc, ("SELECT * FROM %s ORDER BY ID DESCENDING",szTableName));
   if (hstmt<= DB_SUCCESS) {ShowError(); goto Error;}
Some idea ??
Lionel.
Attachments:
code.PNG ‏39 KB
control.png ‏32 KB

Answer 1

Hello Lionel,
According to the document Robert linked, the prototype of DBActivateSQL() is:
int statementHandle = DBActivateSQL (int connectionHandle, char SQLStatement[]);
For the 2nd parameter(SQLStatement), you're sending:
("SELECT * FROM %s ORDER BY ID DESCENDING",szTableName)
Probably your intention is to substitute %s with szTableName, but that's not what it happens.
By using comma operator, ("SELECT * FROM %s ORDER BY ID DESCENDING",szTableName) is evaluated to szTableName, so you call is equivalent to:
hstmt = DBActivateSQL (hdbc, szTableName);
In order to substitute %s with szTableName you need to first build the string you're passing as the 2nd parameter:
char query[512];
sprintf(query, "SELECT * FROM %s ORDER BY ID DESCENDING",szTableName);
hstmt = DBActivateSQL (hdbc, query);