tmudr::OrderInfo Class Reference

Ordering of a table by some ascending or descending columns. More...

#include <sqludr.h>

Public Types
enum	OrderTypeCode { NO_ORDER, ASCENDING, DESCENDING }
	Ascending/descending order of columns. More...
Public Member Functions
int	getNumEntries () const
int	getColumnNum (int i) const
OrderTypeCode	getOrderType (int i) const
void	addEntry (int colNum, OrderTypeCode orderType=ASCENDING)
void	addEntryAt (int pos, int colNum, OrderTypeCode orderType=ASCENDING)
void	clear ()

---

Detailed Description

Ordering of a table by some ascending or descending columns.

A list of columns, represented by column numbers, with an ascending/descending indicator for each column.

---

Member Enumeration Documentation

enum tmudr::OrderInfo::OrderTypeCode

Ascending/descending order of columns.

For outputs, the ordering of values from the first row out to the last. Note that this ordering applies within a parallel instance of the UDF at runtime, but it does not guarantee a total order. For example, two parallel instances may get these ordered values: instance 0 gets 1,3,5,7 instance 1 gets 2,4,6,8

Enumerator:

NO_ORDER	Unspecified order.
ASCENDING	Ascending order.
DESCENDING	Descending order.

---

Member Function Documentation

void OrderInfo::addEntry	(	int	colNum,
		OrderTypeCode	orderType = ASCENDING
	)

Append an entry to the ordering.

Parameters:

	colNum	Column number to append to the ordering.
	orderType	Order type (ascending or descending) to use.

void OrderInfo::addEntryAt	(	int	pos,
		int	colNum,
		OrderTypeCode	orderType = ASCENDING
	)

Insert an entry at any position of the ordering.

A quick example to illustrate this: Let's say we have a table with columns (a,b,c). Their column numbers are 0, 1, and 2. We produce an ordering (C ASCENDING):

 OrderInfo myorder;
  
  myorder.addEntryAt(0, 2); 

Next, we want to make this into (B DESCENDING, C ASCENDING):

 myorder.addEntryAt(0, 1, DESCENDING); 

Parameters:

	pos	Position (0-based) at which we want to insert. The new entry will be position "pos" after the insertion, any existing entries will be moved up.
	colNum	Number of the column by which we want to order
	orderType	Order type (ascending or descending) to use

Exceptions:

UDRException

void OrderInfo::clear

(

)

Clear the contents of the object

int OrderInfo::getColumnNum

(

int

i

)

const

Get the column number of an entry of the ordering.

Parameters:

i

the position (0-based) of the ordering, 0 meaning the leading position.

Returns:

The column number of the n-th entry of the ordering (both are 0-based).

Exceptions:

UDRException

int OrderInfo::getNumEntries

(

)

const

Get the number of entries (columns) in the ordering.

Returns:

Number of entries/columns that make up the ordering.

OrderInfo::OrderTypeCode OrderInfo::getOrderType

(

int

i

)

const

Get the order type of an entry of the ordering.

Parameters:

i

the position (0-based) of the ordering, 0 meaning the leading position.

Returns:

The order type of the n-th entry of the ordering (0-based).

Exceptions:

UDRException

---

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

• sqludr.h
• sqludr.cpp