\section{Database classes overview}\label{odbcoverview}
-Following is a detailed overview of how to use the wxWindows ODBC classes - \helpref{wxDb}{wxdb}
+Following is a detailed overview of how to use the wxWidgets ODBC classes - \helpref{wxDb}{wxdb}
and \helpref{wxDbTable}{wxdbtable} and their associated functions. These are
the ODBC classes donated by Remstar International, and are collectively
referred to herein as the wxODBC classes.
users have successfully used the classes with the following datasources:
\begin{itemize}\itemsep=0pt
-\item Oracle (v7, v8, v8i)
-\item Sybase (ASA and ASE)
-\item MS SQL Server (v7 - minimal testing)
-\item MS Access (97 and 2000)
-\item MySQL
+\item DB2
\item DBase (IV, V)**
-\item PostgreSQL
+\item Firebird
\item INFORMIX
-\item VIRTUOSO
-\item DB2
\item Interbase
+\item MS SQL Server (v7 - minimal testing)
+\item MS Access (97, 2000, 2002, and 2003)
+\item MySQL (2.x and 3.5 - use the 2.5x drivers though)
+\item Oracle (v7, v8, v8i)
\item Pervasive SQL
+\item PostgreSQL
+\item Sybase (ASA and ASE)
+\item XBase Sequiter
+\item VIRTUOSO
\end{itemize}
An up-to-date list can be obtained by looking in the comments of the function
For each result set, a cursor is maintained (typically by the database)
which keeps track of where in the result set the user currently is.
Depending on the database, ODBC driver, and how you configured the
-wxWindows ODBC settings in setup.h (see \helpref{wxODBC - Compiling}{wxodbccompiling}), cursors can be
+wxWidgets ODBC settings in setup.h (see \helpref{wxODBC - Compiling}{wxodbccompiling}), cursors can be
either forward or backward scrolling. At a minimum, cursors must scroll
forward. For example, if a query resulted in a result set with 100 rows,
as the data is read by the client application, it will read row 1, then 2,
Under Unix, iODBC is used for implementation of the ODBC API. To compile the
wxODBC classes, you must first obtain iODBC from \urlref{http://www.iodbc.org}{www.iodbc.org} and install it.
-(Note: wxWindows currently includes a version of iODBC.) Then you must create the file "~/.odbc.ini" (or optionally create
+(Note: wxWidgets currently includes a version of iODBC.) Then you must create the file "~/.odbc.ini" (or optionally create
"/etc/odbc.ini" for access for all users on the system). This file contains
the settings for your system/datasource. Below is an example section of a
odbc.ini file for use with the "samples/db" sample program using MySQL:
\subsection{wxODBC - Compiling}\label{wxodbccompiling}
-The wxWindows setup.h file has several settings in it pertaining to compiling
+The wxWidgets setup.h file has several settings in it pertaining to compiling
the wxODBC classes.
\begin{twocollist}\itemsep=0pt
(see the section in "WHERE TO START" on cursors for more information on
cursors). This default can be overridden by passing a second parameter to
either the \helpref{wxDbGetConnection}{wxdbfunctions} or
-\helpref{wxDb constructor}{wxdbconstr}. The default is 1.}
+\helpref{wxDb constructor}{wxdbctor}. The default is 1.}
\twocolitem{wxODBC\_BACKWARD\_COMPATABILITY}{Between v2.0 and 2.2, massive
renaming efforts were done to the ODBC classes to get naming conventions
-similar to those used throughout wxWindows, as well as to preface all wxODBC
+similar to those used throughout wxWidgets, as well as to preface all wxODBC
classes names and functions with a wxDb preface. Because this renaming would
affect applications written using the v2.0 names, this compile-time directive
was added to allow those programs written for v2.0 to still compile using the
You are required to include the "odbc32.lib" provided by your compiler vendor
in the list of external libraries to be linked in. If using the makefiles
-supplied with wxWindows, this library should already be included for use with
+supplied with wxWidgets, this library should already be included for use with
makefile.b32, makefile.vc, and makefile.g95.
\normalbox{MORE TO COME}
directory indicating where the data file is stored, is required for Text and
dBase drivers for ODBC.
-The wxWindows data class wxDbConnectInf exists for holding all of these
+The wxWidgets data class wxDbConnectInf exists for holding all of these
values, plus some others that may be desired.
The 'Henv' member is the environment handle used to access memory for use by the
will default to only allowing cursor scrolling to be either forward only,
or both backward and forward scrolling. The default behavior is
determined by the setting {\tt wxODBC\_FWD\_ONLY\_CURSORS} in setup.h when you
-compile the wxWindows library. The library default is to only support
+compile the wxWidgets library. The library default is to only support
forward scrolling cursors only, though this can be overridden by parameters
for wxDb() constructor or the \helpref{wxDbGetConnection}{wxdbfunctions}
function. All datasources and ODBC drivers must support forward scrolling
\begin{verbatim}
table->SetColDefs(0, "FIRST_NAME", DB_DATA_TYPE_VARCHAR, FirstName,
- SQL_C_CHAR, sizeof(FirstName), true, true);
+ SQL_C_WXCHAR, sizeof(FirstName), true, true);
table->SetColDefs(1, "LAST_NAME", DB_DATA_TYPE_VARCHAR, LastName,
- SQL_C_CHAR, sizeof(LastName), true, true);
+ SQL_C_WXCHAR, sizeof(LastName), true, true);
\end{verbatim}
Notice that column definitions start at index 0 and go up to one less than
To use the table and the definitions that are now set up, we must first
define what data we want the datasource to collect in to a result set, tell
-it where to get the data from, and in what sequence we want the data returned.
+it where to get the data from, and in which sequence we want the data returned.
\begin{verbatim}
// the WHERE clause limits/specifies which rows in the table
\subsection{wxODBC - Known Issues}\label{wxodbcknownissues}
-As with creating wxWindows, writing the wxODBC classes was not the simple
+As with creating wxWidgets, writing the wxODBC classes was not the simple
task of writing an application to run on a single type of computer system.
The classes need to be cross-platform for different operating systems, and
they also needed to take in to account different database manufacturers and
different ODBC driver manufacturers. Because of all the possible combinations
of OS/database/drivers, it is impossible to say that these classes will work
perfectly with datasource ABC, ODBC driver XYZ, on platform LMN. You may run
-in to some incompatibilities or unsupported features when moving your
+into some incompatibilities or unsupported features when moving your
application from one environment to another. But that is what makes
-cross-platform programming fun. It is also pinpoints one of the great
+cross-platform programming fun. It also pinpoints one of the great
things about open source software. It can evolve!
The most common difference between different database/ODBC driver
\begin{itemize}\itemsep=0pt
\item If a column is part of the Primary Key, the column cannot be NULL.
\item Cannot support selecting for update [\helpref{wxDbTable::CanSelectForUpdate}{wxdbtablecanselectforupdate}]. Always returns false.
-\item Columns that are part of primary or secondary keys must be defined as being NOT NULL when they are created. Some code is added in \helpref{wxDbTable::CreateIndex}{wxdbtablecreateindex} to try to adjust the column definition if it is not defined correctly, but it is experimental (as of wxWindows v2.2.1)
+\item Columns that are part of primary or secondary keys must be defined as being NOT NULL when they are created. Some code is added in \helpref{wxDbTable::CreateIndex}{wxdbtablecreateindex} to try to adjust the column definition if it is not defined correctly, but it is experimental (as of wxWidgets v2.2.1)
\item Does not support sub-queries in SQL statements
\end{itemize}
{\bf UNICODE with wxODBC classes}
-The ODBC classes support for Unicode is yet in early experimental stage and
-hasn't been tested extensively. It might work for you or it might not: please
-report the bugs/problems you have encountered in the latter case.
+As of v2.6 of wxWidgets, the wxODBC classes now fully support the compilation
+and use of the classes in a Unicode build of wxWidgets, assuming the compiler
+and OS on which the program will be compiled/run is Unicode capable.
+
+The one major difference in writing code that can be compiled in either
+unicode or non-unicode builds that is specific to the wxODBC classes is to
+use the SQL\_C\_WXCHAR datatype for string columns rather than SQL\_C\_CHAR or
+SQL\_C\_WCHAR.
\subsection{wxODBC - Sample Code}\label{wxodbcsamplecode1}
// returned back to the client.
//
table->SetColDefs(0, wxT("FIRST_NAME"), DB_DATA_TYPE_VARCHAR, FirstName,
- SQL_C_CHAR, sizeof(FirstName), true, true);
+ SQL_C_WXCHAR, sizeof(FirstName), true, true);
table->SetColDefs(1, wxT("LAST_NAME"), DB_DATA_TYPE_VARCHAR, LastName,
- SQL_C_CHAR, sizeof(LastName), true, true);
+ SQL_C_WXCHAR, sizeof(LastName), true, true);
// -----------------------------------------------------------------------
\helpref{Database classes overview}{odbcoverview}
-\subsubsection{Create}
+\subsubsection{Create}\label{odbccreateexample}
Creates a table.
)
\end{verbatim}
-\subsubsection{Insert}
+\subsubsection{Insert}\label{odbcinsertexample}
Inserts records into a table.
VALUES(5, 'HR', 'The Lark Ascending')
\end{verbatim}
-\subsubsection{Select}
+\subsubsection{Select}\label{odbcselectexample}
The Select operation retrieves rows and columns from a table. The criteria
for selection and the columns returned may be specified.
Selects records where RetailPriceAmount conforms to the WHERE expression.
-\subsubsection{Update}
+\subsubsection{Update}\label{odbcupdateexample}
Updates records in a table.
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