SQLCHAR string_val[1024];
SQLSMALLINT string_len;
SQLRETURN ret;
SQLUINTEGER u_val;
SQLUSMALLINT su_val;

/* for string values */
ret = SQLGetInfo(dbc,
                 SQL_XXX, /* e.g. SQL_DATA_SOURCE_NAME */
		 string_val,
		 sizeof(string_val),
		 &string_len);
if (SQL_SUCCEEDED(ret)) {
   if (ret == SQL_SUCCESS_WITH_INFO)
       printf("buffer too small, string truncated\n");
   printf("Returned value is %s\n", string_val);
} else {
  /* error */
}

/* for SQLUINTEGER values - mostly bitmasks */
ret = SQLGetInfo(dbc,
                 SQL_XXX, /* e.g. SQL_INSERT_STATEMENT */
		 (SQLPOINTER)&u_val,
		 0, /* ignored for SQLUINTEGER types */
		 0); /* ignored for SQLUINTEGER types */
if (SQL_SUCCEEDED(ret)) {
  printf("Returned value is %lx\n", u_val);
} else {
  /* error */
}

/* for SQLUSMALLINT values - mostly counts/limits */
ret = SQLGetInfo(dbc,
                 SQL_XXX, /* e.g. SQL_MAX_CONCURRENT_ACTIVITIES */
		 (SQLPOINTER)&su_val,
		 0, /* ignored for SQLUSMALLINT types */
		 0); /* ignored for SQLUSMALLINT types */
if (SQL_SUCCEEDED(ret)) {
  printf("Returned value is %u\n", su_val);
} else {
  /* error */
}

#include <stdio.h>
#include <sql.h>
#include <sqlext.h>

main() {
  SQLHENV env;
  SQLHDBC dbc;
  SQLRETURN ret; /* ODBC API return status */

  /* Allocate an environment handle */
  SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
  /* We want ODBC 3 support */
  SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (void *) SQL_OV_ODBC3, 0);
  /* Allocate a connection handle */
  SQLAllocHandle(SQL_HANDLE_DBC, env, &dbc);
  /* Connect to the DSN mydsn */
  ret = SQLDriverConnect(dbc, NULL, "DSN=web;", SQL_NTS,
			 NULL, 0, NULL,
			 SQL_DRIVER_COMPLETE);
  if (SQL_SUCCEEDED(ret)) {
    SQLCHAR dbms_name[256], dbms_ver[256];
    SQLUINTEGER getdata_support;
    SQLUSMALLINT max_concur_act;
    SQLSMALLINT string_len;

    printf("Connected\n");
    /*
     *  Find something out about the driver.
     */
    SQLGetInfo(dbc, SQL_DBMS_NAME, (SQLPOINTER)dbms_name,
	       sizeof(dbms_name), NULL);
    SQLGetInfo(dbc, SQL_DBMS_VER, (SQLPOINTER)dbms_ver,
	       sizeof(dbms_ver), NULL);
    SQLGetInfo(dbc, SQL_GETDATA_EXTENSIONS, (SQLPOINTER)&getdata_support,
	       0, 0);
    SQLGetInfo(dbc, SQL_MAX_CONCURRENT_ACTIVITIES, &max_concur_act, 0, 0);

    printf("DBMS Name: %s\n", dbms_name);
    printf("DBMS Version: %s\n", dbms_ver);
    if (max_concur_act == 0) {
      printf("SQL_MAX_CONCURRENT_ACTIVITIES - no limit or undefined\n");
    } else {
      printf("SQL_MAX_CONCURRENT_ACTIVITIES = %u\n", max_concur_act);
    }
    if (getdata_support & SQL_GD_ANY_ORDER)
      printf("SQLGetData - columns can be retrieved in any order\n");
    else
      printf("SQLGetData - columns must be retrieved in order\n");
    if (getdata_support & SQL_GD_ANY_COLUMN)
      printf("SQLGetData - can retrieve columns before last bound one\n");
    else
      printf("SQLGetData - columns must be retrieved after last bound one\n");

    SQLDisconnect(dbc);		/* disconnect from driver */
  } else {
    fprintf(stderr, "Failed to connect\n");

  }
  /* free up allocated handles */
  SQLFreeHandle(SQL_HANDLE_DBC, dbc);
  SQLFreeHandle(SQL_HANDLE_ENV, env);
}