Basic ODBC help!

[mbames]

I am new to C++ (and C in general). I need to write a small console app, that will eventually end up life as a service (but I am not worried about that at the moment).

I need to be able to connect to an Oracle database in order that I can:
(i) store a new record
(ii) retrieve a record

I have had a quick look through the help, and I seem to be getting more and more confused. Does anyone have any example code - at least showing how to open a connection to a DB, store some records....

Cheers,
Matt

 

[palbano]

Hi Matt, for examples and samples in a Windows environment you can try msdn.microsoft.com. Also google.com will find other resources.

I highly recommend using books targeted at beginners to get started. They are much more focused to beginners than the examples you will find online. Also the books tend to flow from start to finish. For example to do ODBC development to Oracle you will need an array of fundamental C/C++ programming knowledge and the books will take you through that first.


-pete

 

[ramijnena]

hi, i need tutorial about connecting visual c++ to SqlServer and how to query data from the database tables , please help me

 

[Cagliostro]

this is a short sample of using ODBC
all rc = something means you must the next verify this rc. I did not put error verification code

#include<iostream>
#include<string>
#include<sql.h>
#include<sqlext.h>
using namespace std;
int main()
{
    HENV hEnv;
    HDBC hDbc;
    RETCODE rc;
    int iOut;
    char strOut[256];
    char szDSN[256] = &quot;driver={Microsoft Access Driver (*.mdb)};dbq=[c:\\db1.mdb];&quot;;
    //dsn samples:
    //&quot;driver={Microsoft Access Driver (*.mdb)};dbq=[f:\\db1.mdb];&quot;
    //&quot;driver={SQL Server};pwd={password there};Server={server name};Database={dbname there}&quot;
    //driver names for different databases:
    //{SQL Server}
    //{Microsoft ODBC for Oracle}
    //{Oracle in oracle9}
    //{Microsoft Access Driver (*.mdb)}
    //{MySQL ODBC 3.51 Driver}

    char* szSql = &quot;select * from table1&quot;;
    rc = SQLAllocEnv(&hEnv);
    rc = SQLAllocConnect(hEnv, &hDbc);

    rc = SQLDriverConnect(hDbc, NULL, (unsigned char*)szDSN, 
        SQL_NTS, (unsigned char*)strOut, 
        255, (SQLSMALLINT*)&iOut, SQL_DRIVER_NOPROMPT);
    {
        int ival;
        char chval[128];
        int ret1;
        int ret2;
        HSTMT hStmt;
        rc = SQLAllocStmt(hDbc,&hStmt);
        rc = SQLPrepare(hStmt,(unsigned char*)szSql, SQL_NTS);//1
        //rc = SQLBindCol(hStmt, tab_column, tr_type, tr_value, tr_len, len_or_ind);
        rc = SQLBindCol(hStmt, 1, SQL_C_ULONG, &ival, 4, (SQLINTEGER*)& ret1);
		rc = SQLBindCol(hStmt, 2, SQL_C_CHAR, chval, 128, (SQLINTEGER*)&ret2);
        rc = SQLExecute(hStmt); //2
        //if you have queries like drop/create/many update... 
        //instead of //1 //2 and //3 you could use
        //rc=SQLExecDirectA(hStmt,(unsigned char*)szSql,SQL_NTS);
        cout<< &quot;>table:&quot;<< endl;
        while(1) //3
        {
            rc = SQLFetch(hStmt);
            if(rc != SQL_SUCCESS && rc != SQL_SUCCESS_WITH_INFO)break;
            cout<< &quot;{&quot;<< ival<<&quot;}{&quot;<< chval<< &quot;}&quot;<< endl;
        }
        rc=SQLFreeStmt(hStmt, SQL_DROP);
    }
    rc = SQLDisconnect(hDbc);
    rc = SQLFreeEnv(hEnv);
    return 0;
}

Ion Filipski

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