| Bug #4432 | Successful status but record not updated | ||
|---|---|---|---|
| Submitted: | 7 Jul 2004 10:11 | Modified: | 30 May 2013 5:28 |
| Reporter: | Nicolas Loechner | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | Connector / ODBC | Severity: | S3 (Non-critical) |
| Version: | 3.51.07 | OS: | Windows (Windows) |
| Assigned to: | Matthew Lord | CPU Architecture: | Any |
[1 Oct 2004 22:59]
Matthew Lord
Dear Sir, Thank you for your bug report! For this kind of general, application layer, row editing to work the table will need a primary key so that each row can be uniquely identified. Try making the unique index the primary key or making the primary key be a combination of two or more of the other indexed columns. The main difference between a primary key and a unique index is that a primary key does not allow null values as it needs to be truly unique and cannot allow multiple null or undefined values. Best Regards
[14 Feb 2005 22:54]
Bugs System
No feedback was provided for this bug for over a month, so it is being suspended automatically. If you are able to provide the information that was originally requested, please do so and change the status of the bug back to "Open".
[30 May 2013 5:28]
Bogdan Degtyariov
I'm closing this bug because I can not continue without feedback from the reporter. If you have new info, please reopen the report.
Description: I'm maintaining a unicode application written in Visual .NET C++ with an ODBC database connection. The problem arises when there are 3 indexes in a table, on field A, on field B and on both fields (A,B), and when there is at least one record with empty(NULL?) values. I search for any record (not necessarily this one with empty values), call Edit(), make changes and call Update() ; ODBC reports no error, yet the record is not updated in the database. I'm not sure if this is a problem with the motor, ODBC, .NET, unicode, or anything else. Also, I'm not sure defining an index on A, B and (A,B) is useful (I'm no database/SQL guru, I'm just maintaining the application). How to repeat: I created a test database called NAMES and the associated DSN. Note that the 3rd element has empty values. Deleting it "solves" the problem. CREATE TABLE t_name ( NUM_NAME int(11) default NULL, STR_NAME varchar(50) default NULL, INFO int(11) default NULL, ID varchar(10) default NULL, UNIQUE KEY IDX_NAME_NUM_NAME (NUM_NAME), KEY idx_info_id (INFO,ID), KEY IDX_INFO (INFO), KEY IDX_ID (ID) ) TYPE=MyISAM; -- -- Dumping data for table `t_name` -- INSERT INTO t_name VALUES (1,'wasntme',231223,'er'); INSERT INTO t_name VALUES (2,'yo!',1,'er'); INSERT INTO t_name VALUES (3,'heyheyhey',0,''); C++ Code : void CTestDBDlg::OnBnClickedButtonTest() { CDatabase *db = NULL; Ct_name *pName = NULL; try { db = new CDatabase (); int nFlags = CDatabase::noOdbcDialog | CDatabase::useCursorLib; CString sDSN (_T("DSN=names")); bool bConnected = db->OpenEx (sDSN, nFlags) ? true : false; if (!bConnected) { TRACE (_T("OpenEx\n")); delete db; return; } pName = new Ct_name (db); pName->m_strFilter.Format (_T("NUM_NAME=%d"), 2); pName->m_strSort = _T(""); pName->Open (); if (!pName->IsOpen ()) { TRACE (_T("IsOpen\n")); delete pName; delete db; return; } if (pName->IsEOF ()) { TRACE (_T("IsEOF\n")); pName->Close (); delete pName; delete db; return; } pName->Edit (); pName->m_STR_NAME = _T("zog?"); pName->m_INFO = 31; pName->SetFieldDirty(NULL,TRUE); if (!pName->Update ()) MessageBox (_T("UPDATE RETURNS 0 (T_NAME).\n")); pName->Close (); delete pName; delete db; TRACE (_T("Successful.\n")); } catch (CDBException *e) { CString tmp; tmp.Format(_T("Error number %d : %s\n"), e->m_nRetCode, ODBC_ERROR_STRING(e)); TRACE (_T("DBException : %s\n"), tmp); if (pName) delete pName; if (db) delete db; } } Ct_name is the standard .NET generated CRecordset class on T_NAME. Suggested fix: I solved my problem by deleting the 3rd index (on both fields (A,B)).