semorg.sql.util
Class DBConstraint

java.lang.Object
  semorg.sql.util.DBConstraint

public class DBConstraint
extends Object

Models a condition of a WHERE-clause, which is structured as follows

< columnName > < relation > < value > < conjunction >,

whereas:

• columnName = attribute of relation (table)
• relation = <, >, !=, =, ~
• value = a value (e.g. 1,'Schmidt', ...)
• conjunction = AND-, OR- or no conjunction

Field Summary

private String	columnName The name of the column which is restricted by the conjunction.
static int	CONJ_AND AND conjunction.
static int	CONJ_END This conjunction type marks the end of chain of conjunctions.
static int	CONJ_OR OR conjunction.
private int	conjunction Conjunction, which appears AFTER the condition (possibly none).
static int	REL_EQ Equality relation.
static int	REL_GREATER "Greater Than" relation.
static int	REL_LESS "Less Than" relation.
static int	REL_LIKE LIKE relation.
static int	REL_NEQ Inequality relation.
private int	relation Relation (<, >, !
private Object	value The value, which restricts the attribute.

Constructor Summary

DBConstraint(String columnName, int relation, Object value, int conjunction)
Creates a DBConstraint instance with the given values.

Method Summary

String	getColumnName()
int	getConjunction()
static int	getConjunction(String conjunctionString) Return for given conjunction string the appropriate conjunction constant.
int	getRelation()
static int	getRelation(String relationString) Returns for a given relation string the appropriate relation constant.
Object	getValue()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

REL_EQ

public static final int REL_EQ

Equality relation.

See Also:

Constant Field Values

REL_NEQ

public static final int REL_NEQ

Inequality relation.

See Also:

Constant Field Values

REL_LESS

public static final int REL_LESS

"Less Than" relation.

See Also:

Constant Field Values

REL_GREATER

public static final int REL_GREATER

"Greater Than" relation.

See Also:

Constant Field Values

REL_LIKE

public static final int REL_LIKE

LIKE relation.

See Also:

Constant Field Values

CONJ_END

public static final int CONJ_END

This conjunction type marks the end of chain of conjunctions.

See Also:

Constant Field Values

CONJ_AND

public static final int CONJ_AND

AND conjunction.

See Also:

Constant Field Values

CONJ_OR

public static final int CONJ_OR

OR conjunction.

See Also:

Constant Field Values

columnName

private String columnName

The name of the column which is restricted by the conjunction.

relation

private int relation

Relation (<, >, !=, =, ~) between attribute and value.

value

private Object value

The value, which restricts the attribute.

conjunction

private int conjunction

Conjunction, which appears AFTER the condition (possibly none).

Constructor Detail

DBConstraint

public DBConstraint(String columnName,
                    int relation,
                    Object value,
                    int conjunction)

Creates a DBConstraint instance with the given values.

Parameters:

columnName - name of the attribute which should be restricted.

relation - Relation between attribute and value.

value - Value to restrict the attribute.

conjunction - Conjunction, which appears AFTER the condition.

Method Detail

getColumnName

public String getColumnName()

getConjunction

public int getConjunction()

getRelation

public int getRelation()

getValue

public Object getValue()

getRelation

public static int getRelation(String relationString)

Returns for a given relation string the appropriate relation constant.

Parameters:

relationString - a string, which contains one of the operators <,>,~,!=, =.

getConjunction

public static int getConjunction(String conjunctionString)

Return for given conjunction string the appropriate conjunction constant.

Parameters:

conjunctionString - String containing a conjunction like "and" / "or".