Class GenericQualifier
- java.lang.Object
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- org.apache.derby.impl.sql.execute.GenericQualifier
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Field Summary
Fields Modifier and Type Field Description private Activation
activation
private int
columnId
private boolean
negateCompareResult
private int
operator
private DataValueDescriptor
orderableCache
private GeneratedMethod
orderableGetter
private boolean
orderedNulls
private boolean
unknownRV
protected int
variantType
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Fields inherited from interface org.apache.derby.iapi.store.access.Qualifier
CONSTANT, QUERY_INVARIANT, SCAN_INVARIANT, VARIANT
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Constructor Summary
Constructors Constructor Description GenericQualifier(int columnId, int operator, GeneratedMethod orderableGetter, Activation activation, boolean orderedNulls, boolean unknownRV, boolean negateCompareResult, int variantType)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
clearOrderableCache()
Clear the DataValueDescriptor cache, if one exists.int
getColumnId()
Get the (zero based) id of the column to be qualified.int
getOperator()
Get the operator to use in the comparison.DataValueDescriptor
getOrderable()
Get the value that the column is to be compared to.boolean
getOrderedNulls()
Get the getOrderedNulls argument to use in the comparison.boolean
getUnknownRV()
Get the getOrderedNulls argument to use in the comparison.boolean
negateCompareResult()
Should the result from the compare operation be negated?void
reinitialize()
This method reinitializes all the state of the Qualifier.java.lang.String
toString()
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Field Detail
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columnId
private int columnId
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operator
private int operator
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orderableGetter
private GeneratedMethod orderableGetter
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activation
private Activation activation
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orderedNulls
private boolean orderedNulls
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unknownRV
private boolean unknownRV
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negateCompareResult
private boolean negateCompareResult
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variantType
protected int variantType
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orderableCache
private DataValueDescriptor orderableCache
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Constructor Detail
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GenericQualifier
public GenericQualifier(int columnId, int operator, GeneratedMethod orderableGetter, Activation activation, boolean orderedNulls, boolean unknownRV, boolean negateCompareResult, int variantType)
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Method Detail
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getColumnId
public int getColumnId()
Description copied from interface:Qualifier
Get the (zero based) id of the column to be qualified.This id is the column number of the column in the table, no matter whether a partial column set is being retrieved by the actual fetch. Note that the column being specified in the qualifier must appear in the column list being fetched.
- Specified by:
getColumnId
in interfaceQualifier
- See Also:
Qualifier.getColumnId()
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getOrderable
public DataValueDescriptor getOrderable() throws StandardException
Description copied from interface:Qualifier
Get the value that the column is to be compared to.- Specified by:
getOrderable
in interfaceQualifier
- Throws:
StandardException
- Thrown on error- See Also:
Qualifier.getOrderable()
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getOperator
public int getOperator()
Get the operator to use in the comparison.- Specified by:
getOperator
in interfaceQualifier
- See Also:
Qualifier.getOperator()
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negateCompareResult
public boolean negateCompareResult()
Should the result from the compare operation be negated? If true then only rows which fail the compare operation will qualify.- Specified by:
negateCompareResult
in interfaceQualifier
- See Also:
Qualifier.negateCompareResult()
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getOrderedNulls
public boolean getOrderedNulls()
Get the getOrderedNulls argument to use in the comparison.- Specified by:
getOrderedNulls
in interfaceQualifier
- See Also:
Qualifier.getOrderedNulls()
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getUnknownRV
public boolean getUnknownRV()
Get the getOrderedNulls argument to use in the comparison.- Specified by:
getUnknownRV
in interfaceQualifier
- See Also:
Qualifier.getUnknownRV()
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clearOrderableCache
public void clearOrderableCache()
Clear the DataValueDescriptor cache, if one exists. (The DataValueDescriptor can be 1 of 3 types: o VARIANT - cannot be cached as its value can vary within a scan o SCAN_INVARIANT - can be cached within a scan as its value will not change within a scan o QUERY_INVARIANT- can be cached across the life of the query as its value will never change o CONSTANT - never changes- Specified by:
clearOrderableCache
in interfaceQualifier
- See Also:
Qualifier.getUnknownRV()
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reinitialize
public void reinitialize()
This method reinitializes all the state of the Qualifier. It is used to distinguish between resetting something that is query invariant and something that is constant over every execution of a query. Basically, clearOrderableCache() will only clear out its cache if it is a VARIANT or SCAN_INVARIANT value. However, each time a query is executed, the QUERY_INVARIANT qualifiers need to be reset.- Specified by:
reinitialize
in interfaceQualifier
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toString
public java.lang.String toString()
- Overrides:
toString
in classjava.lang.Object
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