internal void FillColumnInfo()
{
// Gather the column information for the statement handle
int columnCount;
bool cannotPrefetch = false;
// Count the number of columns
_statementHandle.GetAttribute(OCI.ATTR.OCI_ATTR_PARAM_COUNT, out columnCount, ErrorHandle);
_columnInfo = new OracleColumn[columnCount];
// Create column objects for each column, have them get their
// descriptions and determine their location in a row buffer.
_rowBufferLength = 0;
for (int i = 0; i < columnCount; i++)
{
_columnInfo[i] = new OracleColumn(_statementHandle, i, ErrorHandle, _connection);
if (_columnInfo[i].Describe(ref _rowBufferLength, _connection, ErrorHandle))
{
cannotPrefetch = true;
}
}
if (cannotPrefetch || 0 == _rowBufferLength)
{
_rowsToPrefetch = 1;
}
else
{
_rowsToPrefetch = (_prefetchMemory + _rowBufferLength - 1) / _rowBufferLength; // at least one row...
}
Debug.Assert(1 <= _rowsToPrefetch, "bad prefetch rows value!");
}
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
//
// Constructors
//
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
// Construct from a command and a statement handle
internal OracleDataReader(
OracleCommand command,
OciHandle statementHandle,
string statementText,
CommandBehavior behavior
)
{
_statementHandle = statementHandle;
_connection = (OracleConnection)command.Connection;
_connectionCloseCount = _connection.CloseCount;
_columnInfo = null;
if (OCI.STMT.OCI_STMT_SELECT == command.StatementType)
{
FillColumnInfo();
_recordsAffected = -1; // Don't know this until we read the last row
if (OracleCommand.IsBehavior(behavior, CommandBehavior.SchemaOnly))
{
_endOfData = true;
}
}
else
{
_statementHandle.GetAttribute(OCI.ATTR.OCI_ATTR_ROW_COUNT, out _recordsAffected, ErrorHandle);
_endOfData = true;
_hasRows = x_hasRows_False;
}
_statementText = statementText;
_closeConnectionToo = (OracleCommand.IsBehavior(behavior, CommandBehavior.CloseConnection));
if (CommandType.Text == command.CommandType)
{
_keyInfoRequested = (OracleCommand.IsBehavior(behavior, CommandBehavior.KeyInfo));
}
}
override protected DBSqlParserColumnCollection GatherTableColumns(
DBSqlParserTable table
)
{
// Called to get a column list for the table specified.
OciHandle statementHandle = _connection.EnvironmentHandle.CreateOciHandle(OCI.HTYPE.OCI_HTYPE_STMT);
OciHandle errorHandle = _connection.ErrorHandle;
StringBuilder sb = new StringBuilder();
string schemaName = table.SchemaName;
string tableName = table.TableName;
string columnName;
int tableColumnCount;
int rc;
string tempStatement;
DBSqlParserColumnCollection columns = new DBSqlParserColumnCollection();
Debug.Assert(string.Empty == table.DatabaseName, "oracle doesn't support 4 part names!");
sb.Append("select * from ");
if (String.Empty != schemaName)
{
sb.Append(schemaName);
sb.Append(".");
}
sb.Append(tableName);
tempStatement = sb.ToString();
rc = TracedNativeMethods.OCIStmtPrepare(
statementHandle,
errorHandle,
tempStatement,
tempStatement.Length,
OCI.SYNTAX.OCI_NTV_SYNTAX,
OCI.MODE.OCI_DEFAULT,
_connection
);
if (0 == rc)
{
rc = TracedNativeMethods.OCIStmtExecute(
_connection.ServiceContextHandle,
statementHandle,
errorHandle,
0, // iters
0, // rowoff
ADP.NullHandleRef, // snap_in
ADP.NullHandleRef, // snap_out
OCI.MODE.OCI_DESCRIBE_ONLY // mode
);
if (0 == rc)
{
// Build the column list for the table
statementHandle.GetAttribute(OCI.ATTR.OCI_ATTR_PARAM_COUNT, out tableColumnCount, errorHandle);
for (int j = 0; j < tableColumnCount; j++)
{
OciHandle describeHandle = statementHandle.GetDescriptor(j, errorHandle);
describeHandle.GetAttribute(OCI.ATTR.OCI_ATTR_NAME, out columnName, errorHandle, _connection);
OciHandle.SafeDispose(ref describeHandle);
columnName = QuotePrefixCharacter + columnName + QuoteSuffixCharacter;
columns.Add(null, schemaName, tableName, columnName, null);
}
// Now, derive the key information for the statement and update the column list
// with it.
}
}
// Clean up and return;
OciHandle.SafeDispose(ref statementHandle);
return(columns);
}
