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java.lang.Objectorg.apache.derby.impl.sql.compile.QueryTreeNode
org.apache.derby.impl.sql.compile.ValueNode
org.apache.derby.impl.sql.compile.GenerationClauseNode
public class GenerationClauseNode
This node describes a Generation Clause in a column definition.
Field Summary | |
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private ProviderList |
_apl
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private ValueNode |
_boundExpression
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private java.lang.String |
_expressionText
|
private ValueNode |
_generationExpression
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Fields inherited from class org.apache.derby.impl.sql.compile.ValueNode |
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transformed |
Fields inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode |
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AUTOINCREMENT_CREATE_MODIFY, AUTOINCREMENT_INC_INDEX, AUTOINCREMENT_IS_AUTOINCREMENT_INDEX, AUTOINCREMENT_START_INDEX, isPrivilegeCollectionRequired |
Constructor Summary | |
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GenerationClauseNode()
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Method Summary | |
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ValueNode |
bindExpression(FromList fromList,
SubqueryList subqueryList,
java.util.Vector aggregateVector)
Binding the generation clause. |
java.util.Vector |
findReferencedColumns()
Return a vector of columns referenced in the generation expression. |
void |
generateExpression(ExpressionClassBuilder acb,
MethodBuilder mb)
Generate code for this node. |
ProviderList |
getAuxiliaryProviderList()
Return the auxiliary provider list. |
java.lang.String |
getExpressionText()
Get the defining text of this generation clause |
void |
init(java.lang.Object generationExpression,
java.lang.Object expressionText)
Initialize a query tree node. |
protected boolean |
isEquivalent(ValueNode other)
Tests if this node is equivalent to the specified ValueNode. |
void |
printSubNodes(int depth)
Prints the sub-nodes of this object. |
(package private) void |
setAuxiliaryProviderList(ProviderList apl)
Set the auxiliary provider list. |
java.lang.String |
toString()
Convert this object to a String. |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Field Detail |
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private ValueNode _generationExpression
private java.lang.String _expressionText
private ValueNode _boundExpression
private ProviderList _apl
Constructor Detail |
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public GenerationClauseNode()
Method Detail |
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public void init(java.lang.Object generationExpression, java.lang.Object expressionText)
QueryTreeNode
init
in class QueryTreeNode
public java.lang.String getExpressionText()
void setAuxiliaryProviderList(ProviderList apl)
public ProviderList getAuxiliaryProviderList()
public ValueNode bindExpression(FromList fromList, SubqueryList subqueryList, java.util.Vector aggregateVector) throws StandardException
bindExpression
in class ValueNode
StandardException
public void generateExpression(ExpressionClassBuilder acb, MethodBuilder mb) throws StandardException
generateExpression
in class ValueNode
acb
- The ExpressionClassBuilder for the class being builtmb
- The method the code to place the code
StandardException
- Thrown on errorprotected boolean isEquivalent(ValueNode other) throws StandardException
ValueNode
This method provides basic expression matching facility for the derived class of ValueNode and it is used by the language layer to compare the node structural form of the two expressions for equivalence at bind phase.
Note that it is not comparing the actual row values at runtime to produce a result; hence, when comparing SQL NULLs, they are considered to be equivalent and not unknown.
One usage case of this method in this context is to compare the select column expression against the group by expression to check if they are equivalent. e.g.:
SELECT c1+c2 FROM t1 GROUP BY c1+c2
In general, node equivalence is determined by the derived class of ValueNode. But they generally abide to the rules below:
isEquivalent
in class ValueNode
other
- the node to compare this ValueNode against.
true
if the two nodes are equivalent,
false
otherwise.
StandardException
public java.util.Vector findReferencedColumns() throws StandardException
StandardException
- Thrown on errorpublic java.lang.String toString()
ValueNode
toString
in class ValueNode
public void printSubNodes(int depth)
printSubNodes
in class QueryTreeNode
depth
- The depth of this node in the tree
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