org.apache.derby.impl.sql.compile

Class ColumnReference

java.lang.Object

org.apache.derby.impl.sql.compile.QueryTreeNode

org.apache.derby.impl.sql.compile.ValueNode

org.apache.derby.impl.sql.compile.ColumnReference

All Implemented Interfaces:

Visitable

public class ColumnReference
extends ValueNode

A ColumnReference represents a column in the query tree. The parser generates a ColumnReference for each column reference. A column reference could be a column in a base table, a column in a view (which could expand into a complex expression), or a column in a subquery in the FROM clause.

Field Summary

Fields

Modifier and Type	Field and Description
static int	MERGE_SOURCE
static int	MERGE_TARGET
static int	MERGE_UNKNOWN

Method Summary

Modifier and Type	Method and Description
java.lang.String	getColumnName() Get the name of this column
TableName	getQualifiedTableName() Return the table name as the node it is.
java.lang.String	toString() Convert this object to a String.
boolean	updatableByCursor() Is the column wirtable by the cursor or not.

Methods inherited from class org.apache.derby.impl.sql.compile.ValueNode

checkIsBoolean, selectivity, setCollationInfo, setCollationInfo, setNullability

Methods inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode

accept, addTag, bindOffsetFetch, bindRowMultiSet, bindUserCatalogType, bindUserType, checkReliability, checkReliability, createTypeDependency, getBeginOffset, getDataDictionary, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getOffsetOrderedNodes, getOptimizerFactory, getOptimizerTracer, getParameterTypes, getUDTDesc, isAtomic, makeConstantAction, makeTableName, makeTableName, optimizerTracingIsOn, orReliability, referencesSessionSchema, setBeginOffset, setEndOffset, taggedWith, treePrint

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

MERGE_UNKNOWN

public static final int MERGE_UNKNOWN

See Also:

Constant Field Values

MERGE_SOURCE

public static final int MERGE_SOURCE

See Also:

Constant Field Values

MERGE_TARGET

public static final int MERGE_TARGET

See Also:

Constant Field Values

Method Detail

toString

public java.lang.String toString()

Convert this object to a String. See comments in QueryTreeNode.java for how this should be done for tree printing.

Overrides:

toString in class ValueNode

Returns:

This object as a String

getColumnName

public java.lang.String getColumnName()

Get the name of this column

Returns:

The name of this column

updatableByCursor

public boolean updatableByCursor()

Is the column wirtable by the cursor or not. (ie, is it in the list of FOR UPDATE columns list)

Overrides:

updatableByCursor in class ValueNode

Returns:

TRUE, if the column is a base column of a table and is writable by cursor.

getQualifiedTableName

public TableName getQualifiedTableName()

Return the table name as the node it is.

Returns:

the column's table name.