Deveel.Data.Sql.Query.SortNode Class Reference

Inheritance diagram for Deveel.Data.Sql.Query.SortNode:

Public Member Functions
	SortNode (IQueryPlanNode child, ObjectName[] columnNames, bool[] ascending)
override ITable	Evaluate (IRequest context)

Protected Member Functions
override void	GetData (SerializeData data)
Protected Member Functions inherited from Deveel.Data.Sql.Query.SingleQueryPlanNode
	SingleQueryPlanNode (IQueryPlanNode child)
	SingleQueryPlanNode (ObjectData data)

Properties
ObjectName[]	ColumnNames [get, private set]
bool[]	Ascending [get, private set]
Properties inherited from Deveel.Data.Sql.Query.SingleQueryPlanNode
IQueryPlanNode	Child [get, private set]
	Gets the single child node of the plan. More...

Private Member Functions
	SortNode (ObjectData data)

Detailed Description

Definition at line 25 of file SortNode.cs.

Constructor & Destructor Documentation

Deveel.Data.Sql.Query.SortNode.SortNode ( IQueryPlanNode  child, ObjectName[]  columnNames, bool[]  ascending  )

inline

Definition at line 26 of file SortNode.cs.

            : base(child) {

            // How we handle ascending/descending order
            // ----------------------------------------
            // Internally to the database, all columns are naturally ordered in
            // ascending order (start at lowest and end on highest).  When a column
            // is ordered in descending order, a fast way to achieve this is to take
            // the ascending set and reverse it.  This works for single columns,
            // however some thought is required for handling multiple column.  We
            // order columns from RHS to LHS.  If LHS is descending then this will
            // order the RHS incorrectly if we leave as is.  Therefore, we must do
            // some pre-processing that looks ahead on any descending orders and
            // reverses the order of the columns to the right.  This pre-processing
            // is done in the first pass.

            int sz = ascending.Length;
            for (int n = 0; n < sz - 1; ++n) {
                if (!ascending[n]) {    // if descending...
                    // Reverse order of all columns to the right...
                    for (int p = n + 1; p < sz; ++p) {
                        ascending[p] = !ascending[p];
                    }
                }
            }

            ColumnNames = columnNames;
            Ascending = ascending;
        }

Deveel.Data.Sql.Query.SortNode.SortNode ( ObjectData  data )

inlineprivate

Definition at line 56 of file SortNode.cs.

            : base(data) {
            ColumnNames = data.GetValue<ObjectName[]>("Columns");
            Ascending = data.GetValue<bool[]>("Ascending");
        }

Member Function Documentation

override ITable Deveel.Data.Sql.Query.SortNode.Evaluate ( IRequest  context )

inlinevirtual

Implements Deveel.Data.Sql.Query.SingleQueryPlanNode.

Definition at line 66 of file SortNode.cs.

                                                          {
            var t = Child.Evaluate(context);
            return t.OrderBy(ColumnNames, Ascending);
        }

override void Deveel.Data.Sql.Query.SortNode.GetData ( SerializeData  data )

inlineprotectedvirtual

Reimplemented from Deveel.Data.Sql.Query.SingleQueryPlanNode.

Definition at line 71 of file SortNode.cs.

                                                            {
            data.SetValue("Columns", ColumnNames);
            data.SetValue("Ascending", Ascending);
        }

Property Documentation

bool [] Deveel.Data.Sql.Query.SortNode.Ascending

getprivate set

Definition at line 64 of file SortNode.cs.

ObjectName [] Deveel.Data.Sql.Query.SortNode.ColumnNames

getprivate set

Definition at line 62 of file SortNode.cs.

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The documentation for this class was generated from the following file:

• /var/calculate/remote/distfiles/egit-src/deveeldb.git/src/deveeldb/Deveel.Data.Sql.Query/SortNode.cs