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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.DefaultNode
public class DefaultNode
DefaultNode represents a column/parameter default.
Field Summary | |
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private java.lang.String |
columnName
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private java.lang.String |
defaultText
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private ValueNode |
defaultTree
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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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DefaultNode()
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Method Summary | |
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ValueNode |
bindExpression(FromList fromList,
SubqueryList subqueryList,
java.util.Vector aggregateVector)
Bind this expression. |
void |
generateExpression(ExpressionClassBuilder acb,
MethodBuilder mb)
Generate code for this calculation. |
java.lang.String |
getDefaultText()
Get the text of the default. |
(package private) ValueNode |
getDefaultTree()
Get the query tree for the default. |
void |
init(java.lang.Object columnName)
Initializer for insert/update |
void |
init(java.lang.Object defaultTree,
java.lang.Object defaultText)
Initializer for a column/parameter default. |
protected boolean |
isEquivalent(ValueNode other)
Tests if this node is equivalent to the specified ValueNode. |
static ValueNode |
parseDefault(java.lang.String defaultText,
LanguageConnectionContext lcc,
CompilerContext cc)
Parse a default and turn it into a query tree. |
void |
printSubNodes(int depth)
Prints the sub-nodes of this object. |
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 java.lang.String columnName
private java.lang.String defaultText
private ValueNode defaultTree
Constructor Detail |
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public DefaultNode()
Method Detail |
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public void init(java.lang.Object defaultTree, java.lang.Object defaultText)
init
in class QueryTreeNode
defaultTree
- Query tree for defaultdefaultText
- The text of the default.public void init(java.lang.Object columnName)
init
in class QueryTreeNode
public java.lang.String getDefaultText()
ValueNode getDefaultTree()
public java.lang.String toString()
toString
in class ValueNode
public void printSubNodes(int depth)
printSubNodes
in class QueryTreeNode
depth
- The depth of this node in the treepublic ValueNode bindExpression(FromList fromList, SubqueryList subqueryList, java.util.Vector aggregateVector) throws StandardException
bindExpression
in class ValueNode
fromList
- The FROM list for the query this
expression is in, for binding columns.subqueryList
- The subquery list being built as we find SubqueryNodesaggregateVector
- The aggregate vector being built as we find AggregateNodes
StandardException
- Thrown on failurepublic static ValueNode parseDefault(java.lang.String defaultText, LanguageConnectionContext lcc, CompilerContext cc) throws StandardException
defaultText
- Text of Default.lcc
- LanguageConnectionContextcc
- CompilerContext
StandardException
- Thrown on failurepublic void generateExpression(ExpressionClassBuilder acb, MethodBuilder mb) throws StandardException
ValueNode
generateExpression
in class ValueNode
acb
- The ExpressionClassBuilder for the class being builtmb
- The method the expression will go into
StandardException
- Thrown on failureprotected boolean isEquivalent(ValueNode other)
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.
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Built on Thu 2012-03-29 21:53:33+0000, from revision ??? | ||||||||
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