| public ToArray ( ) : Deveel.Data.Index.IndexRange[] | ||
| Результат | Deveel.Data.Index.IndexRange[] | |
/// <inheritdoc/>
public override ITable Evaluate(IQueryContext context)
{
var t = Child.Evaluate(context);
var exp = Expression;
// Assert that all variables in the expression are identical.
var columnNames = exp.DiscoverReferences();
ObjectName columnName = null;
foreach (var cv in columnNames) {
if (columnName != null && !cv.Equals(columnName))
throw new InvalidOperationException("Range plan does not contain common column.");
columnName = cv;
}
// Find the variable field in the table.
var col = t.IndexOfColumn(columnName);
if (col == -1)
throw new InvalidOperationException("Could not find column reference in table: " + columnName);
var field = t.TableInfo[col];
// Calculate the range
var range = new IndexRangeSet();
var calculator = new RangeSetCalculator(context, field, range);
range = calculator.Calculate(exp);
// Select the range from the table
var ranges = range.ToArray();
return t.SelectRange(columnName, ranges);
}
public static IEnumerable<int> SelectRows(this ITable table, int column, SqlExpressionType op, DataObject value)
{
// If the cell is of an incompatible type, return no results,
var colType = table.TableInfo[column].ColumnType;
if (!value.Type.IsComparable(colType)) {
// Types not comparable, so return 0
return new List<int>(0);
}
// Get the selectable scheme for this column
var index = table.GetIndex(column);
// If the operator is a standard operator, use the interned SelectableScheme
// methods.
if (op == SqlExpressionType.Equal)
return index.SelectEqual(value);
if (op == SqlExpressionType.NotEqual)
return index.SelectNotEqual(value);
if (op == SqlExpressionType.GreaterThan)
return index.SelectGreater(value);
if (op == SqlExpressionType.SmallerThan)
return index.SelectLess(value);
if (op == SqlExpressionType.GreaterOrEqualThan)
return index.SelectGreaterOrEqual(value);
if (op == SqlExpressionType.SmallerOrEqualThan)
return index.SelectLessOrEqual(value);
// If it's not a standard operator (such as IS, NOT IS, etc) we generate the
// range set especially.
var rangeSet = new IndexRangeSet();
rangeSet = rangeSet.Intersect(op, value);
return index.SelectRange(rangeSet.ToArray());
}
