public override Task <SqlObject> GetValueAsync(long row, int column)
{
int tableNum = JoinedTableInfo.GetTableOffset(column);
var parentTable = Tables[tableNum];
var resolvedRow = ResolveTableRow(row, tableNum);
return(parentTable.GetValueAsync(resolvedRow, JoinedTableInfo.GetColumnOffset(column)));
}
protected override TableIndex GetColumnIndex(int column, int originalColumn, ITable ancestor)
{
// First check if the given SelectableScheme is in the column_scheme array
var scheme = Indexes[column];
if (scheme != null)
{
if (ancestor == this)
{
return(scheme);
}
return(scheme.Subset(ancestor, originalColumn));
}
// If it isn't then we need to calculate it
TableIndex index;
// Optimization: The table may be naturally ordered by a column. If it
// is we don't try to generate an ordered set.
if (SortColumn != -1 &&
SortColumn == column)
{
var columnName = JoinedTableInfo.Columns[column].ColumnName;
var indexInfo = new IndexInfo($"#COLIDX[{column}]", TableInfo.TableName, columnName);
index = new InsertSearchIndex(indexInfo, this, CalculateTableRows());
Indexes[column] = index;
if (ancestor != this)
{
index = index.Subset(ancestor, originalColumn);
}
}
else
{
// Otherwise we must generate the ordered set from the information in
// a parent index.
var parentTable = Tables[JoinedTableInfo.GetTableOffset(column)];
index = parentTable.GetColumnIndex(JoinedTableInfo.GetColumnOffset(column), originalColumn, ancestor);
if (ancestor == this)
{
Indexes[column] = index;
}
}
return(index);
}
protected override IEnumerable <long> ResolveRows(int column, IEnumerable <long> rowSet, ITable ancestor)
{
if (ancestor == this)
{
return(new BigArray <long>(0));
}
int tableNum = JoinedTableInfo.GetTableOffset(column);
var parentTable = Tables[tableNum];
if (!(parentTable is IVirtualTable))
{
throw new InvalidOperationException();
}
// Resolve the rows into the parents indices
var rows = ResolveTableRows(rowSet, tableNum);
return(parentTable.ResolveRows(JoinedTableInfo.GetColumnOffset(column), rows, ancestor));
}
public override Task <SqlObject> GetValueAsync(long row, int column)
{
int tableNum = JoinedTableInfo.GetTableOffset(column);
var parentTable = Tables[tableNum];
if (row >= outerRowCount)
{
row = Rows[tableNum][row - outerRowCount];
return(parentTable.GetValueAsync(row, JoinedTableInfo.GetColumnOffset(column)));
}
if (outerRows[tableNum] == null)
{
// Special case, handling outer entries (NULL)
return(Task.FromResult(new SqlObject(TableInfo.Columns[column].ColumnType, null)));
}
row = outerRows[tableNum][row];
return(parentTable.GetValueAsync(row, JoinedTableInfo.GetColumnOffset(column)));
}