[GENERAL] Username and Password authentication using pqxx library.

[aravind chandu]

Hello,

            I am using pqxx API for postgresql.The following is the part of my 
code.The problem is in the query I am selecting the number of rows from the 
table since there is only one user name and password row it should return 1 and 
if there is no match then it should return 0.But here Even though I give wrong 
username or password its getting authenticated.please help me,what should I put 
in the "if ()" statement inorder to solve this issue .

result R(T.exec("select count(*) from dbtable where username="+username+" and 
password="+password+""));
    
    if (R.empty()) 
        {
            throw logic_error("No tables found");
            *shm = '5';
        }
    else
        {
            cout<<"Authenticated";
            *shm='0';
        }

Thank You,
Avinash.