Package org.apache.derby.vti
Class Restriction
- java.lang.Object
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- org.apache.derby.vti.Restriction
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- All Implemented Interfaces:
java.io.Serializable
- Direct Known Subclasses:
Restriction.AND
,Restriction.ColumnQualifier
,Restriction.OR
public abstract class Restriction extends java.lang.Object implements java.io.Serializable
An expression to be pushed into a Table Function so that the Table Function can short-circuit its processing and return fewer rows. A restriction is represented as a binary tree. The non-leaf nodes are ANDs and ORs. The leaf nodes are ColumnQualifiers. A ColumnQualifier is a simple expression comparing a constant value to a column in the Table Function.
- See Also:
- Serialized Form
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
Restriction.AND
An AND of two Restrictionsstatic class
Restriction.ColumnQualifier
A simple comparison of a column to a constant value.static class
Restriction.OR
An OR of two Restrictions
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Constructor Summary
Constructors Constructor Description Restriction()
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected java.lang.String
parenthesize(java.lang.String raw)
Utility method to parenthesize an expressionabstract java.lang.String
toSQL()
Turn this Restriction into a string suitable for use in a WHERE clause.
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