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Documentation for wxDbGrid from patch 638274

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Updates with the aim of improving readability.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@18111 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Roger Gammans
2002-12-08 16:10:50 +00:00
parent f24badde9a
commit cdbecb3946
1 changed files with 201 additions and 0 deletions
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docs/latex/wx/db.tex
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@@ -3930,3 +3930,204 @@ an introduction to using the ODBC classes.
Simply initializes all member variables to a cleared state. Called by
the constructor automatically.
\section{\class{wxDbGridColInfo}}\label{wxdbgridcolinfo}
This class is used to define columns to be shown, names of the columns,
order and type of data, when using \helpref{wxdbGridTableBase}{wxdbgridtablebase} to display
a Table or query in a \helpref{wxGrid}{wxgrid}
See the database grid example in \helpref{wxDbGridTableBase}{wxdbgridtablebase} for
an introduction to using the wxDbGrid classes.
\wxheading{Include files}
<wx/dbgrid.h>
\latexignore{\rtfignore{\wxheading{Members}}}
\membersection{wxDbGridColInfo::wxDbGridColInfo}\label{wxdbgridcolinfo}
\func{}{wxDbGridColInfo}{\param{int }{colNo}, \param{wxString }{type},
\param{wxString }{title}, \param{wxDbGridColInfo *}{next}}
Default constructor. See the database grid example in \helpref{wxDbGridTableBase}{wxdbgridtablebase} to
see two different ways for adding columns.
\wxheading{Parameters}
\docparam{colNo}{Column number in the \helpref{wxDbTable}{wxdbtable} instance to be used (first column is 0).}
\docparam{type}{Column type ,wxString specifying the grid name for the datatype in this column, or
use wxGRID_VALUE_DBAUTO to determine the type automatically from the \helpref{wxDbColDef}{wxdbcoldef} definition}
\docparam{title}{The column label to be used in the grid display}
\docparam{next}{A pointer to the next wxDbGridColInfo structure if using one-step
construction, NULL terminates the list. Use Null also if using two step construction.}
See the database grid example in \helpref{wxDbGridTableBase}{wxdbgridtablebase} to
see two different ways for adding columns.
\membersection{wxDbGridColInfo::\destruct{wxDbGridColInfo}}
\func{}{\destruct{wxDbGridColInfo}}{}
Destructor.
\membersection{wxDbGridColInfo::AddColInfo}\label{wxdbgridcolinfoaddcolinfo}
\func{void}{AddColInfo}{\param{int }{colNo},
\param{wxString }{type}, \param{wxString }{title}}
Use this member function for adding columns. See the database
grid example in \helpref{wxDbGridTableBase}{wxdbgridtablebase} to
see two different ways for adding columns.
It is important to note that this class is merely a specifier to the \helpref{wxDbGridTableBase}{wxdbgridtablebase}
constructor. Changes made to this datatype after the \helpref{wxDbGridTableBase}{wxdbgridtablebase} is called will
not have any effect.
\wxheading{Parameters}
\docparam{colNo}{Column number in the \helpref{wxDbTable}{wxdbtable} instance to be used (first column is 0).}
\docparam{type}{Column type ,wxString specifying the grid name for the datatype in this column, or
use wxGRID_VALUE_DBAUTO to determine the type automatically from the \helpref{wxDbColDef}{wxdbcoldef} definition}
\docparam{title}{The column label to be used in the grid display}
\wxheading{Remarks}
As wxDbTable must be defined with to have columns which match those to by a wxDbGridColInfo
info structure as this is the structure which informs the grid of how you want to display your
\helpref{wxDbTable}{wxdbtable}. If no datatype conversion or the referenced column number does not exist the
the behavior is undefined.
See the example at \helpref{wxDbGridColInfo::wxDbGridColInfo}{wxdbgridcolinfo}.
\section{\class{wxDbGridTableBase}}\label{wxdbgridtablebase}
You can view a database table in a grid using this class.
If you are deriving your own wxDbTable subclass for your table , then you may consider
overriding GetCol() and SetCol() to provide calculated fields. This does work but care should
be taken when using wxDbGridTableBase in this way.
The constructor and AssignDbTable() call allows you to specify the ownership if the wxDbTable
object pointer. If you tell wxGridTableBase to take ownership , it will delete the passed wxDbTable
when an new on is assigned or wxGridTableBase's destructor is called.
However no checks for aliasing are done so Assign(table,..,true); Assign(table,..,true);
is an error. If you need to requery an table object the preferred way is
that the client keeps ownership.
\wxheading{Derived From}
\helpref{wxGridTableBase}{wxgridtablebase}
\wxheading{Include files}
<wx/dbgrid.h>
\wxheading{Example}
\begin{verbatim}
// First step, let's define wxDbTable
int numColumns = 2;
wxDbTable *table = new wxDbTable (db, tblName, numColumns);
int int_var;
wxChar string_name[255];
table->SetColDef (0, "column 0", DB_DATA_TYPE_INTEGER, &int_var,
SQL_C_LONG, sizeof(int_var), TRUE);
table->SetColDef (1, "column 1", DB_DATA_TYPE_VARCHAR, &string_name,
SQL_C_LONG, sizeof(string_name), FALSE);
// now let's define columns in the grid
// first way to do it
wxDbGridColInfo *columns;
columns = new wxDbGridColInfo(0, wxGRID_VALUE_LONG, "first column",
new wxDbGridColInfo(1, wxGRID_VALUE_STRING, "second column",
NULL);
// second way to do it
wxDbGridColInfo *columns;
// first column is special
columns = new wxDbGridColInfo(0, wxGRID_VALUE_LONG, "first column", NULL);
// all the rest
columns->AddColInfo (1, wxGRID_VALUE_STRING, "second column");
// second way may be better when columns are not known at compile time
// now, let's open the table and make a Query()
table->Open();
// this step is very important
table->SetRowMode (wxDbTable::WX_ROW_MODE_QUERY);
// in the grid we will see only the rows of the result query
m_dbTable->Query();
wxDbGridTableBase *dbgrid = new wxDbGridTableBase(table, columns, wxUSE_QUERY, TRUE);
delete columns; // not needed anymore
wxGrid *grid = new wxGrid ( ... );
grid->SetTable(dbgrid, TRUE);
grid->Fit();
\end{verbatim}
\wxheading{Include files}
<wx/dbgrid.h>
\wxheading{Helper classes and data structures}
\membersection{wxDbGridTableBase::wxDbGridTableBase}\label{wxdbgridtablebaseconstr}
\func{}{wxDbGridTableBase}{\param{wxDbTable *}{tab}, \param{wxDbGridColInfo *}{ColInfo},
\param{int }{count = wxUSE_QUERY}, \param{bool }{takeOwnership = TRUE}}
Constructor.
\wxheading{Parameters}
\docparam{tab}{ The database table you want to display. Must be opened and queried before display the grid.
See the example \helpref{above}{wxdbgridtablebase}.}
\docparam{ColInfo}{ Columns titles, and other values. See \helpref{wxDbGridColInfo}{wxdbgridcolinfo}.}
\docparam{count}{You can use a query result set (wxUSE_QUERY, to use wxDbTable::Count(wxDbTable::Count()
or you can fix the total number of rows (count >= 0) to display, or specify it if you already know the size in avoid calling }
\docparam{takeOwnership}{ If TRUE, this class deletes wxDbTable when it stops
referring to it, if FALSE application must
take care of deleting it. }
\membersection{wxDbGridTableBase::ValidateRow}\label{wxdbgridtablebasevalidate}
\func{void}{ValidateRow}{\param{int }{row}}
It ensures that the row data is fetched from the database, and it the wxDbTable local buffer,
the row number passed should be the grid row.
\wxheading{Parameters}
\docparam{row}{ Row where validation must be done. }
\membersection{wxDbGridTableBase::UpdateRow}\label{wxdbgridtablebaseupdaterow}
\func{bool}{UpdateRow}{\param{int }{row}}
If row has changed it forces that row to be written back to the database, however support
for detecting whether insert/update is required is currently not in wxDbTable, so this
function is currently unsupported.
\wxheading{Parameters}
\docparam{row}{ Row you want to update. }
\membersection{wxDbGridTableBase::AssignDbTable}\label{wxdbgridtablebaseassigndbtable}
\func{bool}{AssignDbTable}{\param{wxDbTable *}{tab},\param{int }{count = wxUSE_QUERY},
\param{bool }{takeOwnership = TRUE}}
Resets the grid for using with a new database table, but using the same columns definition.
This can be useful when re-querying the database and want to see the changes.
\wxheading{Parameters}
\docparam{tab}{ Database table you want to assign to the grid. }
\docparam{count}{ Number of rows you want to show or wxUSE_QUERY for using a query. }
\docparam{takeOwnership}{ If FALSE, user must take care of deleting tab after deleting
the wxDbGridTableBase. If TRUE, deletion is made by destructor class. }