Hi Frnds,

Any possiblilities their in C to connect DataBase. If possibilities their Explain Any one to me?


yuva

hi

i think there is no possibilities in c to connect the database..

one possible solution is ..... use Structures & Structure pointers to simulate the above requirements

__________________
SeeSamJagan
- Sky is not the "LIMIT", Death is not the END, There is still something beyond....

Hi ,
Oracle provides a tool as "pro C".that is used to coonect oracle to C program.
while in other databases there must be some native calls(API of database) provided by that database.using these calls you can connect that database.

regards,

M.Sundaram

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sqlcli1.h>
#include "utilcli.h" /* Header file for CLI sample code */

int DbBasicConnect(SQLHANDLE, char *, char *, char *);
int DbDriverConnect(SQLHANDLE, char *, char *, char *);
int DbBrowseConnect(SQLHANDLE, char *, char *, char *);

int main(int argc, char *argv[])
{
SQLRETURN cliRC = SQL_SUCCESS;
int rc = 0;
SQLHANDLE henv; /* environment handle */
SQLHANDLE hdbc; /* connection handle */

char dbAlias[SQL_MAX_DSN_LENGTH + 1];
char user[MAX_UID_LENGTH + 1];
char pswd[MAX_PWD_LENGTH + 1];

/* check the command line arguments */
rc = CmdLineArgsCheck1(argc, argv, dbAlias, user, pswd);
if (rc != 0)
{
return 1;
}

printf("\nTHIS SAMPLE SHOWS ");
printf("HOW TO CONNECT TO AND DISCONNECT FROM A DATABASE.\n");

/* allocate an environment handle */
cliRC = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
if (cliRC != SQL_SUCCESS)
{
printf("\n--ERROR while allocating the environment handle.\n");
printf(" cliRC = %d\n", cliRC);
printf(" line = %d\n", __LINE__);
printf(" file = %s\n", __FILE__);
return 1;
}

/* set attribute to enable application to run as ODBC 3.0 application */
cliRC = SQLSetEnvAttr(henv,
SQL_ATTR_ODBC_VERSION,
(void *)SQL_OV_ODBC3,
0);
ENV_HANDLE_CHECK(henv, cliRC);

/* connect to a database with SQLConnect() */
/* this is the basic connection */
rc = DbBasicConnect(henv, dbAlias, user, pswd);
if (rc != 0)
{
return rc;
}

/* connect to a database with SQLDriverConnect() */
rc = DbDriverConnect(henv, dbAlias, user, pswd);
if (rc != 0)
{
return rc;
}

/* connect to a database with SQLBrowseConnect() */
rc = DbBrowseConnect(henv, dbAlias, user, pswd);
if (rc != 0)
{
return rc;
}

/* free the environment handle */
cliRC = SQLFreeHandle(SQL_HANDLE_ENV, henv);
ENV_HANDLE_CHECK(henv, cliRC);

return 0;
} /* main */

/* connect to a database with a basic connection using SQLConnect() */
int DbBasicConnect(SQLHANDLE henv,
char db1Alias[],
char user[],
char pswd[])
{
SQLRETURN cliRC = SQL_SUCCESS;
int rc = 0;
SQLHANDLE hdbc; /* connection handle */

printf("\n-----------------------------------------------------------");
printf("\nUSE THE CLI FUNCTIONS\n");
printf(" SQLAllocHandle\n");
printf(" SQLConnect\n");
printf(" SQLDisconnect\n");
printf(" SQLFreeHandle\n");
printf("TO CONNECT TO AND DISCONNECT FROM A DATABASE:\n");

/* allocate a database connection handle */
cliRC = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
ENV_HANDLE_CHECK(henv, cliRC);

printf("\n Connecting to the database %s ...\n", db1Alias);

/* connect to the database */
cliRC = SQLConnect(hdbc,
(SQLCHAR *)db1Alias,
SQL_NTS,
(SQLCHAR *)user,
SQL_NTS,
(SQLCHAR *)pswd,
SQL_NTS);
DBC_HANDLE_CHECK(hdbc, cliRC);
printf(" Connected to the database %s.\n", db1Alias);

/********* Start using the connection *************************/

/********* Stop using the connection **************************/

printf("\n Disconnecting from the database %s...\n", db1Alias);

/* disconnect from the database */
cliRC = SQLDisconnect(hdbc);
DBC_HANDLE_CHECK(hdbc, cliRC);

printf(" Disconnected from the database %s.\n", db1Alias);

/* free the connection handle */
cliRC = SQLFreeHandle(SQL_HANDLE_DBC, hdbc);
DBC_HANDLE_CHECK(hdbc, cliRC);

return 0;
} /* DbBasicConnect */

/* connect to a database with additional connection parameters
using SQLDriverConnect() */
int DbDriverConnect(SQLHANDLE henv,
char db1Alias[],
char user[],
char pswd[])
{
SQLRETURN cliRC = SQL_SUCCESS;
int rc = 0;
SQLHANDLE hdbc; /* connection handle */
SQLCHAR connStr[255];

printf("\n-----------------------------------------------------------");
printf("\nUSE THE CLI FUNCTIONS\n");
printf(" SQLAllocHandle\n");
printf(" SQLDriverConnect\n");
printf(" SQLDisconnect\n");
printf(" SQLFreeHandle\n");
printf("TO CONNECT TO AND DISCONNECT FROM A DATABASE:\n");

/* allocate a database connection handle */
cliRC = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
ENV_HANDLE_CHECK(henv, cliRC);

printf("\n Connecting to the database %s ...\n", db1Alias);
sprintf((char *)connStr,
"DSN=%s; UID=%s; PWD=%s; AUTOCOMMIT=0; CONNECTTYPE=1;",
db1Alias, user, pswd);

/* connect to a data source */
cliRC = SQLDriverConnect(hdbc,
(SQLHWND)NULL,
connStr,
SQL_NTS,
NULL,
0,
NULL,
SQL_DRIVER_NOPROMPT);
DBC_HANDLE_CHECK(hdbc, cliRC);

printf(" Connected to the database %s.\n", db1Alias);

/********* Start using the connection *************************/

/********* Stop using the connection **************************/

printf("\n Disconnecting from the database %s...\n", db1Alias);

/* disconnect from the database */
cliRC = SQLDisconnect(hdbc);
DBC_HANDLE_CHECK(hdbc, cliRC);

printf(" Disconnected from the database %s.\n", db1Alias);

/* free the connection handle */
cliRC = SQLFreeHandle(SQL_HANDLE_DBC, hdbc);
DBC_HANDLE_CHECK(hdbc, cliRC);

return 0;
} /* DbDriverConnect */

/* connect to a database iteratively using SQLBrowseConnect() */
int DbBrowseConnect(SQLHANDLE henv,
char db1Alias[],
char user[],
char pswd[])
{
SQLRETURN cliRC = SQL_SUCCESS;
int rc = 0;
SQLHANDLE hdbc; /* connection handle */
SQLCHAR connInStr[255]; /* browse request connection string */
SQLCHAR outStr[1025]; /* browse result connection string*/
SQLSMALLINT indicator; /* number of bytes to return */
int count = 1;

printf("\n-----------------------------------------------------------");
printf("\nUSE THE CLI FUNCTIONS:\n");
printf(" SQLAllocHandle\n");
printf(" SQLBrowseConnect\n");
printf(" SQLDisconnect\n");
printf(" SQLFreeHandle\n");
printf("TO CONNECT TO AND DISCONNECT FROM A DATABASE:\n");

/* allocate a database connection handle */
cliRC = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
ENV_HANDLE_CHECK(henv, cliRC);

/* connect to the database */
printf("\n Connecting to the database %s ...\n", db1Alias);
sprintf((char *)connInStr,
"DSN=%s; UID=%s; PWD=%s; AUTOCOMMIT=0;", db1Alias, user, pswd);

/********* Start using the connection *************************/

cliRC = SQL_NEED_DATA;
while (cliRC == SQL_NEED_DATA)
{
/* get required attributes to connect to data source */
cliRC = SQLBrowseConnect(hdbc,
connInStr,
SQL_NTS,
outStr,
sizeof(outStr),
&indicator);
DBC_HANDLE_CHECK(hdbc, cliRC);

printf(" So far, have connected %d times to database %s\n",
count++, db1Alias);
printf(" Resulting connection string: %s\n", outStr);

/* if inadequate connection information was provided, exit
the program */
if (cliRC == SQL_NEED_DATA)
{
printf(" You can provide other connection information "
"here by setting connInStr\n");
break;
}

/* if the connection was successful, output confirmation */
if (cliRC == SQL_SUCCESS)
{
printf(" Connected to the database %s.\n", db1Alias);
}
}

/********* Stop using the connection **************************/

printf("\n Disconnecting from the database %s...\n", db1Alias);

/* disconnect from the database */
cliRC = SQLDisconnect(hdbc);
DBC_HANDLE_CHECK(hdbc, cliRC);

printf(" Disconnected from the database %s.\n", db1Alias);

/* free the connection handle */
cliRC = SQLFreeHandle(SQL_HANDLE_DBC, hdbc);
DBC_HANDLE_CHECK(hdbc, cliRC);

return 0;
} /* DbBrowseConnect */

__________________
Shaalini.S
Be the Best of Whatever you are...

The easiest way to access an Access database from C++ is to use ODBC. An access database can easily be setup as an ODBC data source.

(OR)

Earlier the program is using MS access database and code is like below.

CDaoDatabase* pDB = NULL;
pDB = new CDaoDatabase;
char query[256], *name;
try
{
// Force usage of latest DAO engine
AfxGetModuleState()->m_dwVersion = 0x0601;
AfxDaoInit();

char *dbPath = new char[strlen(envVar) + 40];
sprintf(dbPath, "%s\\MilkDB.mdb",envVar );
pDB->Open(dbPath);
}