Hello, I found a script to handle database connection and queries.
// ----------------------------------------------------------------------------
// HEADERS
// ----------------------------------------------------------------------------
#include "wx/log.h" // #included to enable output of messages only
#include "wx/dbtable.h"
// ----------------------------------------------------------------------------
// FUNCTION USED FOR HANDLING/DISPLAYING ERRORS
// ----------------------------------------------------------------------------
// Very generic error handling function.
// If a connection to the database is passed in, then we retrieve all the
// database errors for the connection and add them to the displayed message
int HandleError(wxString errmsg, wxDb *pDb=NULL)
{
// Retrieve all the error message for the errors that occurred
wxString allErrors;
if (!pDb == NULL)
// Get the database errors and append them to the error message
allErrors = wxDbLogExtendedErrorMsg(errmsg.c_str(), pDb, 0, 0);
else
allErrors = errmsg;
// Do whatever you wish with the error message here
// wxLogDebug() is called inside wxDbLogExtendedErrorMsg() so this
// console program will show the errors in the console window,
// but these lines will show the errors in RELEASE builds also
wxFprintf(stderr, wxT("\n%s\n"), allErrors.c_str());
fflush(stderr);
return 1;
}
// ----------------------------------------------------------------------------
// entry point
// ----------------------------------------------------------------------------
int connexion()
{
wxDbConnectInf *DbConnectInf = NULL; // DB connection information
wxDb *db = NULL; // Database connection
wxDbTable *table = NULL; // Data table to access
const wxChar tableName[] = wxT("USERS"); // Name of database table
const UWORD numTableColumns = 2; // Number table columns
wxChar FirstName[50+1]; // column data: "FIRST_NAME"
wxChar LastName[50+1]; // column data: "LAST_NAME"
wxString msg; // Used for display messages
// -----------------------------------------------------------------------
// DEFINE THE CONNECTION HANDLE FOR THE DATABASE
// -----------------------------------------------------------------------
DbConnectInf = new wxDbConnectInf(NULL,
wxT("CONTACTS-SqlServer"),
wxT("sa"),
wxT("abk"));
// Error checking....
if (!DbConnectInf || !DbConnectInf->GetHenv())
{
return HandleError(wxT("DB ENV ERROR: Cannot allocate ODBC env handle"));
}
// -----------------------------------------------------------------------
// GET A DATABASE CONNECTION
// -----------------------------------------------------------------------
db = wxDbGetConnection(DbConnectInf);
if (!db)
{
return HandleError(wxT("CONNECTION ERROR - Cannot get DB connection"));
}
// -----------------------------------------------------------------------
// DEFINE THE TABLE, AND THE COLUMNS THAT WILL BE ACCESSED
// -----------------------------------------------------------------------
table = new wxDbTable(db, tableName, numTableColumns, wxT(""),
!wxDB_QUERY_ONLY, wxT(""));
//
// Bind the columns that you wish to retrieve. Note that there must be
// 'numTableColumns' calls to SetColDefs(), to match the wxDbTable def
//
// Not all columns need to be bound, only columns whose values are to be
// returned back to the client.
//
table->SetColDefs(0, wxT("FIRST_NAME"), DB_DATA_TYPE_VARCHAR, FirstName,
SQL_C_WXCHAR, sizeof(FirstName), true, true);
table->SetColDefs(1, wxT("LAST_NAME"), DB_DATA_TYPE_VARCHAR, LastName,
SQL_C_WXCHAR, sizeof(LastName), true, true);
// -----------------------------------------------------------------------
// CREATE (or RECREATE) THE TABLE IN THE DATABASE
// -----------------------------------------------------------------------
if (!table->CreateTable(true)) //NOTE: No CommitTrans is required
{
return HandleError(wxT("TABLE CREATION ERROR: "), table->GetDb());
}
// -----------------------------------------------------------------------
// OPEN THE TABLE FOR ACCESS
// -----------------------------------------------------------------------
if (!table->Open())
{
return HandleError(wxT("TABLE OPEN ERROR: "), table->GetDb());
}
// -----------------------------------------------------------------------
// INSERT A NEW ROW INTO THE TABLE
// -----------------------------------------------------------------------
wxStrcpy(FirstName, wxT("JULIAN"));
wxStrcpy(LastName, wxT("SMART"));
if (!table->Insert())
{
return HandleError(wxT("INSERTION ERROR: "), table->GetDb());
}
// Must commit the insert to write the data to the DB
table->GetDb()->CommitTrans();
// -----------------------------------------------------------------------
// RETRIEVE ROWS FROM THE TABLE BASED ON SUPPLIED CRITERIA
// -----------------------------------------------------------------------
// Set the WHERE clause to limit the result set to return
// all rows that have a value of 'JULIAN' in the FIRST_NAME
// column of the table.
table->SetWhereClause(wxT("FIRST_NAME = 'JULIAN'"));
// Result set will be sorted in ascending alphabetical
// order on the data in the 'LAST_NAME' column of each row
table->SetOrderByClause(wxT("LAST_NAME"));
// No other tables (joins) are used for this query
table->SetFromClause(wxT(""));
// Instruct the datasource to perform a query based on the
// criteria specified above in the where/orderBy/from clauses.
if (!table->Query())
{
return HandleError(wxT("QUERY ERROR: "), table->GetDb());
}
// Loop through all rows matching the query criteria until
// there are no more records to rea d
while (table->GetNext())
{
msg.Printf(wxT("Row #%lu -- First Name : %s Last Name is %s"),
table->GetRowNum(), FirstName, LastName);
// Code to display 'msg' here
wxLogMessage(wxT("\n%s\n"), msg.c_str());
}
// -----------------------------------------------------------------------
// DELETE A ROW FROM THE TABLE
// -----------------------------------------------------------------------
// Select the row which has FIRST_NAME of 'JULIAN' and LAST_NAME
// of 'SMART', then delete the retrieved row
//
if (!table->DeleteWhere(wxT("FIRST_NAME = 'JULIAN' and LAST_NAME = 'SMART'")))
{
return HandleError(wxT("DELETION ERROR: "), table->GetDb());
}
// Must commit the deletion to the database
table->GetDb()->CommitTrans();
// -----------------------------------------------------------------------
// TAKE CARE OF THE ODBC CLASS INSTANCES THAT WERE BEING USED
// -----------------------------------------------------------------------
// If the wxDbTable instance was successfully created
// then delete it as we are done with it now.
wxDELETE(table);
// Free the cached connection
// (meaning release it back in to the cache of datasource
// connections) for the next time a call to wxDbGetConnection()
// is made.
wxDbFreeConnection(db);
db = NULL;
// -----------------------------------------------------------------------
// CLEANUP BEFORE EXITING APP
// -----------------------------------------------------------------------
// The program is now ending, so we need to close
// any cached connections that are still being
// maintained.
wxDbCloseConnections();
// Release the environment handle that was created
// for use with the ODBC datasource connections
wxDELETE(DbConnectInf);
//wxUnusedVar(argc); // Here just to prevent compiler warnings
//wxUnusedVar(argv); // Here just to prevent compiler warnings
return 0;
}
I cannot understand those errors when I compile.
