// GetStatementHandle
// ------------------
// Try to return a cached statement handle.
//
// Creates a CmdWrapper object if necessary
// If no handle is available a handle will be allocated.
// Bindings will be unbound if a handle is cached and the bindings are invalid.
//
internal HandleRef GetStatementHandle()
{
ODBC32.RETCODE retcode;
// update the command wrapper object, allocate buffer
// create reader object
//
if (_cmdWrapper == null)
{
_cmdWrapper = new CMDWrapper();
}
_cmdWrapper._connection = _connection;
_cmdWrapper._connectionId = _connection._dbcWrapper._instanceId;
_cmdWrapper._cmdText = _cmdText;
if (_cmdWrapper._dataReaderBuf == null)
{
_cmdWrapper._dataReaderBuf = new CNativeBuffer(4096);
}
// if there is already a statement handle we need to do some cleanup
//
if (_cmdWrapper._stmt != IntPtr.Zero)
{
if ((null != _parameterCollection) && (0 < _parameterCollection.Count))
{
if (_parameterCollection.CollectionIsBound && _parameterCollection.BindingIsValid)
{
retcode = (ODBC32.RETCODE)UnsafeNativeMethods.Odbc32.SQLFreeStmt(
_cmdWrapper,
(short)ODBC32.STMT.UNBIND
);
// UNBIND should never fail so we assert only
if (retcode != ODBC32.RETCODE.SUCCESS)
{
Debug.Assert(false, "SQLFreeStmt(hstmt, (short)ODBC32.STMT.UNBIND) failed");
}
_parameterCollection.CollectionIsBound = false;
}
}
}
else
{
_isPrepared = false; // a new statement can't be prepare
if (null != _parameterCollection)
{
_parameterCollection.CollectionIsBound = false;
}
_cmdWrapper.AllocateStatementHandle(ref _cmdWrapper._stmt);
}
return(_cmdWrapper);
}