tmudr::PredicateInfo Class Reference

A predicate to be evaluated on a table. More...

#include <sqludr.h>

Inheritance diagram for tmudr::PredicateInfo:

Public Types
enum	EvaluationCode { UNKNOWN_EVAL = 0, EVALUATE_ON_RESULT = 0x1, EVALUATE_IN_UDF = 0x2, EVALUATE_IN_CHILD = 0x4 }
	Info on whether a table-valued input or output column is used. More...
enum	PredOperator {   UNKNOWN_OP, EQUAL, NOT_EQUAL, LESS,   LESS_EQUAL, GREATER, GREATER_EQUAL, IN,   NOT_IN }
Public Member Functions
EvaluationCode	getEvaluationCode () const
PredOperator	getOperator () const
bool	isAComparisonPredicate () const

---

Detailed Description

A predicate to be evaluated on a table.

These could be different kinds of predicates, like an equals predicate, a non-equals predicate or more complex cases.

---

Member Enumeration Documentation

enum tmudr::PredicateInfo::EvaluationCode

Info on whether a table-valued input or output column is used.

Note that these are not necessarily exclusive, a predicate might be evaluated in multiple places, although that should not be common and is not yet allowed.

Enumerator:

UNKNOWN_EVAL	Not yet determined where predicate is evaluated.
EVALUATE_ON_RESULT	Predicate is evaluated on the UDF result, in Trafodion code. This is the default.
EVALUATE_IN_UDF	Predicate is evaluated inside the code provided by the UDR writer.
EVALUATE_IN_CHILD	Predicate should be evaluated in a table-valued input before the data reaches the UDF.

enum tmudr::PredicateInfo::PredOperator

Operator of a relational (comparison) predicate

Enumerator:

UNKNOWN_OP	Operator not yet determined.
EQUAL	Equals predicate (col = val).
NOT_EQUAL	Not equals predicate (col <> val).
LESS	Less than predicate (col <).
LESS_EQUAL	Less or equals predicate (col <=).
GREATER	Greater predicate (col >).
GREATER_EQUAL	Greater or equals predicate (col >=).
IN	IN predicate (col IN).
NOT_IN	NOT IN predicate (col NOT IN).

---

Member Function Documentation

PredicateInfo::EvaluationCode PredicateInfo::getEvaluationCode

(

)

const

Get evaluation code for a predicate.

Returns:

Evaluation code.

Exceptions:

UDRException

PredicateInfo::PredOperator PredicateInfo::getOperator

(

)

const

Get operator code for a predicate.

Returns:

Operator code.

Exceptions:

UDRException

bool PredicateInfo::isAComparisonPredicate

(

)

const

Check whether this predicate is a comparison predicate.

Use this method to determine whether it is safe to cast the object to class ComparisonPredicateInfo.

Returns:

true if predcate i is a comparison predicate, false otherwise.

---

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

• sqludr.h
• sqludr.cpp