执行Update语句示例代码

void main()
{
  char szDSN[] = "XuguDB";
    char szUID[] = "SYSDBA";
    char szAuth[] = "SYSDBA";
    SQLHENV henv = NULL;
    SQLHDBC hdbc = NULL;
    SQLHSTMT hstmt = NULL;
    SQLRETURN ret = 0;
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
    ret = SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (SQLPOINTER)SQL_OV_ODBC3, SQL_IS_INTEGER);
    ret = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
    ret = SQLConnect(hdbc, (SQLCHAR*)szDSN, SQL_NTS, (SQLCHAR*)szUID, SQL_NTS, (SQLCHAR*)szAuth, SQL_NTS);
    if (ret != SQL_SUCCESS)
    {
        SQLCHAR sqlState[128];
        SQLINTEGER nativeErr;
        SQLCHAR errMsg[256];
        SQLSMALLINT len;
        SQLGetDiagRec(SQL_HANDLE_DBC, hdbc, 1, sqlState, &nativeErr, errMsg, 200, &len);
        printf("Can't connect to server, reason: %s\n", errMsg);
        SQLFreeHandle(SQL_HANDLE_DBC, hdbc);
        SQLFreeHandle(SQL_HANDLE_ENV, henv);
        return;
    }
    printf("Connect successful!\n");
    ret = SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt);
    char sql[] = "update mytable set c2 = 'update' where c1 = 1";
    ret = SQLExecDirect(hstmt, (SQLCHAR*)sql, SQL_NTS);
    if (ret != SQL_SUCCESS)
    {
        SQLCHAR sqlState[128];
        SQLINTEGER nativeErr;
        SQLCHAR errMsg[256];
        SQLSMALLINT len;
        SQLGetDiagRec(SQL_HANDLE_STMT, hstmt, 1, sqlState, &nativeErr, errMsg, 200, &len);
        printf("SQLExecDirect failed, reason: %s\n", errMsg);
    }
    else
        printf("Update successful!\n");
    ret = SQLFreeHandle(SQL_HANDLE_STMT, hstmt);
    ret = SQLDisconnect(hdbc);
    ret = SQLFreeHandle(SQL_HANDLE_DBC, hdbc);
    ret = SQLFreeHandle(SQL_HANDLE_ENV, henv);
}