用Visual C++开发数据库应用程序(二)(6)

SQLCHAR szConnStrIn[BRWS_LEN], szConnStrOut[BRWS_LEN];

SQLSMALLINT cbConnStrOut;/* Allocate the environment handle. */

retcode = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);

if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO) {

/* Set the version environment attribute. */

retcode = SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, SQL_OV_ODBC3, 0);

if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO) {

/* Allocate the connection handle. */

retcode = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);

if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO) {

/* Call SQLBrowseConnect until it returns a value other than */

/* SQL_NEED_DATA (pass the data source name the first time). */

/* If SQL_NEED_DATA is returned, call GetUserInput (not */

/* shown) to build a dialog from the values in szConnStrOut. */

/* The user-supplied values are returned in szConnStrIn, */

/* which is passed in the next call to SQLBrowseConnect. */

lstrcpy(szConnStrIn, "DSN=Sales"); do {

retcode = SQLBrowseConnect(hdbc, szConnStrIn, SQL_NTS,

szConnStrOut, BRWS_LEN, &cbConnStrOut);

if (retcode == SQL_NEED_DATA)

GetUserInput(szConnStrOut, szConnStrIn);

} while (retcode == SQL_NEED_DATA);

if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO){

/* Allocate the statement handle. */

retcode = SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt);

if (retcode == SQL_SUCCESS || retcode == SQL_SUCCESS_WITH_INFO) {

/* Process data after successful connection */ ...;

SQLFreeHandle(SQL_HANDLE_STMT, hstmt); }

SQLDisconnect(hdbc); } }

SQLFreeHandle(SQL_HANDLE_DBC, hdbc); }}

SQLFreeHandle(SQL_HANDLE_ENV, henv);