Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.sql.execute.GenericScanQualifier

Modifier and Type	Field and Description
private int	columnId
private boolean	negateCR
private int	operator
private DataValueDescriptor	orderable
private boolean	orderedNulls
private boolean	properInit
private boolean	unknownRV

Access	Constructor and Description
public	GenericScanQualifier()

Method Summary

Modifier and Type	Method and Description
public void	clearOrderableCache() Implements org.apache.derby.iapi.store.access.Qualifier.clearOrderableCache. Clear the DataValueDescriptor cache, if one exists.
public int	getColumnId() Implements org.apache.derby.iapi.store.access.Qualifier.getColumnId. Get the (zero based) id of the column to be qualified.
public int	getOperator() Implements org.apache.derby.iapi.store.access.Qualifier.getOperator. Get the operator to use in the comparison.
public DataValueDescriptor	getOrderable() Implements org.apache.derby.iapi.store.access.Qualifier.getOrderable. Get the value that the column is to be compared to.
public boolean	getOrderedNulls() Implements org.apache.derby.iapi.store.access.Qualifier.getOrderedNulls. Get the getOrderedNulls argument to use in the comparison.
public boolean	getUnknownRV() Implements org.apache.derby.iapi.store.access.Qualifier.getUnknownRV. Get the getOrderedNulls argument to use in the comparison.
public boolean	negateCompareResult() Implements org.apache.derby.iapi.store.access.Qualifier.negateCompareResult. Should the result from the compare operation be negated?
public void	reinitialize() Implements org.apache.derby.iapi.store.access.Qualifier.reinitialize. This method reinitializes all the state of the Qualifier.
public void	setQualifier(int columnId, DataValueDescriptor orderable, int operator, boolean negateCR, boolean orderedNulls, boolean unknownRV) Implements org.apache.derby.iapi.sql.execute.ScanQualifier.setQualifier. Set the info in a ScanQualifier

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

columnId	back to summary
private int columnId

negateCR	back to summary
private boolean negateCR

operator	back to summary
private int operator

orderable	back to summary
private DataValueDescriptor orderable

orderedNulls	back to summary
private boolean orderedNulls

properInit	back to summary
private boolean properInit

unknownRV	back to summary
private boolean unknownRV

GenericScanQualifier	back to summary
public GenericScanQualifier()

Method Detail

clearOrderableCache back to summary

clearOrderableCache	back to summary
public void clearOrderableCache() Implements org.apache.derby.iapi.store.access.Qualifier.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 - immutable See Also `Qualifier#getUnknownRV`

public void clearOrderableCache()

Implements org.apache.derby.iapi.store.access.Qualifier.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 - immutable

See Also: Qualifier#getUnknownRV

getColumnId back to summary

getColumnId	back to summary
public int getColumnId() Implements org.apache.derby.iapi.store.access.Qualifier.getColumnId. Doc from org.apache.derby.iapi.store.access.Qualifier.getColumnId. 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. See Also `Qualifier#getColumnId`

public int getColumnId()

Implements org.apache.derby.iapi.store.access.Qualifier.getColumnId.

Doc from org.apache.derby.iapi.store.access.Qualifier.getColumnId.

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.

See Also: Qualifier#getColumnId

getOperator back to summary

getOperator	back to summary
public int getOperator() Implements org.apache.derby.iapi.store.access.Qualifier.getOperator. Get the operator to use in the comparison. See Also `Qualifier#getOperator`

public int getOperator()

Implements org.apache.derby.iapi.store.access.Qualifier.getOperator.

Get the operator to use in the comparison.

See Also: Qualifier#getOperator

getOrderable back to summary

getOrderable	back to summary
public DataValueDescriptor getOrderable() Implements org.apache.derby.iapi.store.access.Qualifier.getOrderable. Doc from org.apache.derby.iapi.store.access.Qualifier.getOrderable. Get the value that the column is to be compared to. See Also `Qualifier#getOrderable`

public DataValueDescriptor getOrderable()

Implements org.apache.derby.iapi.store.access.Qualifier.getOrderable.

Doc from org.apache.derby.iapi.store.access.Qualifier.getOrderable.

Get the value that the column is to be compared to.

See Also: Qualifier#getOrderable

getOrderedNulls back to summary

getOrderedNulls	back to summary
public boolean getOrderedNulls() Implements org.apache.derby.iapi.store.access.Qualifier.getOrderedNulls. Get the getOrderedNulls argument to use in the comparison. See Also `Qualifier#getOrderedNulls`

public boolean getOrderedNulls()

Implements org.apache.derby.iapi.store.access.Qualifier.getOrderedNulls.

Get the getOrderedNulls argument to use in the comparison.

See Also: Qualifier#getOrderedNulls

getUnknownRV back to summary

getUnknownRV	back to summary
public boolean getUnknownRV() Implements org.apache.derby.iapi.store.access.Qualifier.getUnknownRV. Get the getOrderedNulls argument to use in the comparison. See Also `Qualifier#getUnknownRV`

public boolean getUnknownRV()

Implements org.apache.derby.iapi.store.access.Qualifier.getUnknownRV.

Get the getOrderedNulls argument to use in the comparison.

See Also: Qualifier#getUnknownRV

negateCompareResult back to summary

negateCompareResult	back to summary
public boolean negateCompareResult() Implements org.apache.derby.iapi.store.access.Qualifier.negateCompareResult. Should the result from the compare operation be negated? If true then only rows which fail the compare operation will qualify. See Also `Qualifier#negateCompareResult`

public boolean negateCompareResult()

Implements org.apache.derby.iapi.store.access.Qualifier.negateCompareResult.

Should the result from the compare operation be negated? If true then only rows which fail the compare operation will qualify.

See Also: Qualifier#negateCompareResult

reinitialize	back to summary
public void reinitialize() Implements org.apache.derby.iapi.store.access.Qualifier.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.

reinitialize

back to summary

public void reinitialize()

Implements org.apache.derby.iapi.store.access.Qualifier.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.

setQualifier back to summary

setQualifier	back to summary
public void setQualifier(int columnId, DataValueDescriptor orderable, int operator, boolean negateCR, boolean orderedNulls, boolean unknownRV) Implements org.apache.derby.iapi.sql.execute.ScanQualifier.setQualifier. Doc from org.apache.derby.iapi.sql.execute.ScanQualifier.setQualifier. Set the info in a ScanQualifier See Also `ScanQualifier#setQualifier`

public void setQualifier(int columnId, DataValueDescriptor orderable, int operator, boolean negateCR, boolean orderedNulls, boolean unknownRV)

Implements org.apache.derby.iapi.sql.execute.ScanQualifier.setQualifier.

Doc from org.apache.derby.iapi.sql.execute.ScanQualifier.setQualifier.

Set the info in a ScanQualifier

See Also: ScanQualifier#setQualifier

public Class GenericScanQualifier

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Method Detail