Pro*C :ORA-01012: not logged on

Hi, every one:
[Quoted] I am working on a project with pro*C/C++ v8.0.4.000. I integrated pro*C/C++ with Visual C++ 5.0. Every thing looks fine. I just pick a sample from Oracle, sample6.pc and compiled it. Perfect! No error. I ran it, it connected to Oracle server.ok. but when it executed first SQL command, I got an error:ORA-01012: not logged on. It doesn't any sense to me. On my machine, I have a lot of oracle tools which can work without any problem!

Can any expert help me?

Thanks.

Here is the piece of the source code:

 char *username = "linxtest";
 char *password = "linxtest";
 char *dbstring = "linx";

EXEC SQL WHENEVER SQLERROR DO sql_error();  //Connect to database
 EXEC SQL DECLARE DB_NAME DATABASE; /*I jus link to our database*/
EXEC SQL CONNECT :username IDENTIFIED BY :password   AT DB_NAME USING :dbstring;
 printf( "Connected to Oracle as: %s\n", username);

/* Execute a string literal to create the table.  This

• usage is actually not dynamic because the program does
• not determine the SQL statement at run time. */ puts("CREATE TABLE dyn1 (col1 VARCHAR2(4))"); /* Here I got "ORA-01012: not logged on" */ EXEC SQL EXECUTE IMMEDIATE "CREATE TABLE dyn1 (col1 VARCHAR2(4))";

/* Execute a string to insert a row.  The string must

• be null-terminated. This usage is dynamic because the
• SQL statement is a string variable whose contents the
• program can determine at run time. */ strcpy((char *)dynstmt1, "INSERT INTO DYN1 values ('TEST')"); puts(dynstmt1); EXEC SQL EXECUTE IMMEDIATE :dynstmt1; ..... .....