Deveel.Data.Routines.AggregateFunction Class Reference

Inheritance diagram for Deveel.Data.Routines.AggregateFunction:

Public Member Functions
override InvokeResult	Execute (InvokeContext context)
	Executes the function and provides a result. More...
Public Member Functions inherited from Deveel.Data.Routines.Function
SqlType	ReturnType ()
	Gets the function static return type More...
virtual SqlType	ReturnType (InvokeContext context)
	Resolves the function return type against the given context. More...

Protected Member Functions
	AggregateFunction (ObjectName name, RoutineParameter[] parameters, SqlType returnType)
abstract DataObject	Evaluate (DataObject value1, DataObject value2, IRequest query, IGroupResolver group)
virtual DataObject	PostEvaluate (DataObject result, IRequest query, IGroupResolver group)
Protected Member Functions inherited from Deveel.Data.Routines.Function
	Function (FunctionInfo functionInfo)
	Function (ObjectName name, RoutineParameter[] parameters, FunctionType functionType)
	Function (ObjectName name, RoutineParameter[] parameters, SqlType returnType)
	Function (ObjectName name, RoutineParameter[] parameters, SqlType returnType, FunctionType functionType)

Additional Inherited Members
Static Public Attributes inherited from Deveel.Data.Routines.Function
static readonly SqlType	DynamicType = new DynamicSqlType()
	A special SqlType that is used to mark an argument of a function as dynamic. More...
Properties inherited from Deveel.Data.Routines.Function
FunctionType	FunctionType [get]
FunctionInfo	FunctionInfo [get, private set]
ObjectName	FunctionName [get]
RoutineInfo IRoutine.	RoutineInfo [get]
RoutineType IRoutine.	Type [get]
DbObjectType IDbObject.	ObjectType [get]
ObjectName IDbObject.	FullName [get]
Properties inherited from Deveel.Data.Routines.IFunction
FunctionType	FunctionType [get]
	Gets the type of function. More...
Properties inherited from Deveel.Data.Routines.IRoutine
RoutineType	Type [get]
	Gets the type of routine that will be executed. More...
RoutineInfo	RoutineInfo [get]
Properties inherited from Deveel.Data.Sql.IDbObject
ObjectName	FullName [get]
	Gets the fully qualified name of the object used to resolve it uniquely within the database. More...
DbObjectType	ObjectType [get]
	Gets the type of database object that the implementation is for More...

Detailed Description

Definition at line 25 of file AggregateFunction.cs.

Constructor & Destructor Documentation

Deveel.Data.Routines.AggregateFunction.AggregateFunction ( ObjectName  name, RoutineParameter[]  parameters, SqlType  returnType  )

inlineprotected

Definition at line 26 of file AggregateFunction.cs.

            : base(name, parameters, returnType, FunctionType.Aggregate) {
        }

Member Function Documentation

abstract DataObject Deveel.Data.Routines.AggregateFunction.Evaluate ( DataObject  value1, DataObject  value2, IRequest  query, IGroupResolver  group  )

protectedpure virtual

override InvokeResult Deveel.Data.Routines.AggregateFunction.Execute ( InvokeContext  context )

inlinevirtual

Executes the function and provides a result.

Parameters

context

The context of the execution.

Returns

Returns a InvokeResult instance that encapsulates the returned value of the function.

See also

InvokeResult.ReturnValue

Implements Deveel.Data.Routines.Function.

Definition at line 37 of file AggregateFunction.cs.

                                                                    {
            if (context == null)
                throw new ArgumentNullException("context");

            var group = context.GroupResolver;

            if (group == null)
                throw new Exception(String.Format("'{0}' can only be used as an aggregate function.", FunctionName));

            DataObject result = null;
            // All aggregates functions return 'null' if group size is 0
            int size = group.Count;
            if (size == 0) {
                // Return a NULL of the return type
                return context.Result(DataObject.Null(ReturnType(context)));
            }

            DataObject val;
            ObjectName v = context.Arguments[0].AsReferenceName();
            // If the aggregate parameter is a simple variable, then use optimal
            // routine,
            if (v != null) {
                for (int i = 0; i < size; ++i) {
                    val = group.Resolve(v, i);
                    result = Evaluate(result, val, context.Request, group);
                }
            } else {
                // Otherwise we must resolve the expression for each entry in group,
                // This allows for expressions such as 'sum(quantity * price)' to
                // work for a group.
                var exp = context.Arguments[0];
                for (int i = 0; i < size; ++i) {
                    val = exp.EvaluateToConstant(context.Request, group.GetVariableResolver(i));
                    result = Evaluate(result, val, context.Request, group);
                }
            }

            // Post method.
            result = PostEvaluate(result, context.Request, group);

            return context.Result(result);
        }

virtual DataObject Deveel.Data.Routines.AggregateFunction.PostEvaluate ( DataObject  result, IRequest  query, IGroupResolver  group  )

inlineprotectedvirtual

Definition at line 32 of file AggregateFunction.cs.

                                                                                                           {
            // By default, do nothing....
            return result;
        }

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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.Routines/AggregateFunction.cs