Class CastNode
- java.lang.Object
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- org.apache.derby.impl.sql.compile.QueryTreeNode
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- org.apache.derby.impl.sql.compile.ValueNode
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- org.apache.derby.impl.sql.compile.CastNode
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Field Summary
Fields Modifier and Type Field Description private boolean
assignmentSemantics
Method calls: Argument type has the same semantics as assignment: Section 9.2 (Store assignment).(package private) ValueNode
castOperand
private boolean
externallyGeneratedCastNode
This variable gets set by the parser to indicate that this CAST node has been generated by the parser.private boolean
forDataTypeFunction
(package private) TypeId
sourceCTI
private int
targetCharType
private DataTypeDescriptor
targetUDT
The original, unbound descriptor for the target type, if it is a UDT.private TableName
udtTargetName
The name of the target type if it's a UDT.-
Fields inherited from class org.apache.derby.impl.sql.compile.ValueNode
transformed
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Fields inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode
AUTOINCREMENT_CREATE_MODIFY, AUTOINCREMENT_CYCLE, AUTOINCREMENT_INC_INDEX, AUTOINCREMENT_IS_AUTOINCREMENT_INDEX, AUTOINCREMENT_START_INDEX
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Constructor Summary
Constructors Constructor Description CastNode(ValueNode castOperand, int charType, int charLength, ContextManager cm)
Constructor for a CastNodeCastNode(ValueNode castOperand, DataTypeDescriptor castTarget, ContextManager cm)
Constructor for a CastNode
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description (package private) void
acceptChildren(Visitor v)
Accept the visitor for all visitable children of this node.(package private) void
bindCastNodeOnly()
Bind this node but not its child.(package private) ValueNode
bindExpression(FromList fromList, SubqueryList subqueryList, java.util.List<AggregateNode> aggregates)
Bind this expression.(package private) boolean
categorize(JBitSet referencedTabs, boolean simplePredsOnly)
Categorize this predicate.(package private) boolean
constantExpression(PredicateList whereClause)
Return whether or not this expression tree represents a constant value.private void
genDataValueConversion(ExpressionClassBuilder acb, MethodBuilder mb)
(package private) void
generateExpression(ExpressionClassBuilder acb, MethodBuilder mb)
Do code generation for this unary operator.private ValueNode
getCastFromCharConstant(int destJDBCTypeId)
Get a constant representing the cast from a CHAR to another type.private ValueNode
getCastFromIntegralType(long longValue, int destJDBCTypeId)
Get a constant representing the cast from an integral type to another type.private ValueNode
getCastFromNumericType(DataValueDescriptor constantValue, int destJDBCTypeId)
Get a constant representing the cast from a non-integral type to another type.(package private) java.lang.Object
getConstantValueAsObject()
Return an Object representing the bind time value of this expression tree.protected int
getOrderableVariantType()
Return the variant type for the underlying expression.(package private) boolean
isConstantExpression()
Return whether or not this expression tree represents a constant expression.(package private) boolean
isEquivalent(ValueNode o)
Tests if this node is equivalent to the specified ValueNode.(package private) ValueNode
preprocess(int numTables, FromList outerFromList, SubqueryList outerSubqueryList, PredicateList outerPredicateList)
Preprocess an expression tree.(package private) void
printSubNodes(int depth)
Prints the sub-nodes of this object.(package private) ValueNode
remapColumnReferencesToExpressions()
Remap all ColumnReferences in this tree to be clones of the underlying expression.(package private) void
setAssignmentSemantics()
Set assignmentSemantics to true.(package private) void
setForDataTypeFunction(boolean b)
set this to be a dataTypeScalarFunction(package private) void
setForExternallyGeneratedCASTnode()
This method gets called by the parser to indiciate that this CAST node has been generated by the parser.(package private) void
setTargetUDTName(TableName name)
Set the target type name if this is a cast to a UDT.java.lang.String
toString()
Convert this object to a String.-
Methods inherited from class org.apache.derby.impl.sql.compile.ValueNode
bindExpression, changeToCNF, checkIsBoolean, checkTopPredicatesForEqualsConditions, copyFields, eliminateNots, evaluateConstantExpressions, genEqualsFalseTree, generate, genIsNullTree, genSQLJavaSQLTree, getClone, getColumnName, getDataValueFactory, getSchemaName, getSourceResultColumn, getTableName, getTablesReferenced, getTransformed, getTypeCompiler, getTypeId, getTypeServices, isBinaryEqualsOperatorNode, isBooleanFalse, isBooleanTrue, isCloneable, isInListProbeNode, isParameterNode, isRelationalOperator, isSameNodeKind, optimizableEqualityNode, putAndsOnTop, requiresTypeFromContext, selectivity, setCollationInfo, setCollationInfo, setCollationUsingCompilationSchema, setCollationUsingCompilationSchema, setNullability, setTransformed, setType, setType, setType, updatableByCursor, verifyChangeToCNF, verifyEliminateNots, verifyPutAndsOnTop
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Methods inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode
accept, addTag, addUDTUsagePriv, addUDTUsagePriv, bindOffsetFetch, bindRowMultiSet, bindUserCatalogType, bindUserType, checkReliability, checkReliability, convertDefaultNode, copyTagsFrom, createTypeDependency, debugFlush, debugPrint, disablePrivilegeCollection, formatNodeString, generateAuthorizeCheck, getBeginOffset, getClassFactory, getCompilerContext, getContext, getContextManager, getDataDictionary, getDependencyManager, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getIntProperty, getLanguageConnectionContext, getLongProperty, getNullNode, getOffsetOrderedNodes, getOptimizerFactory, getOptimizerTracer, getParameterTypes, getSchemaDescriptor, getSchemaDescriptor, getStatementType, getTableDescriptor, getTypeCompiler, getUDTDesc, isAtomic, isPrivilegeCollectionRequired, isSessionSchema, isSessionSchema, makeConstantAction, makeTableName, makeTableName, nodeHeader, optimizerTracingIsOn, orReliability, parseSearchCondition, parseStatement, printLabel, referencesSessionSchema, resolveTableToSynonym, setBeginOffset, setEndOffset, setRefActionInfo, stackPrint, taggedWith, treePrint, treePrint, verifyClassExist
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Field Detail
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castOperand
ValueNode castOperand
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targetCharType
private int targetCharType
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sourceCTI
TypeId sourceCTI
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forDataTypeFunction
private boolean forDataTypeFunction
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targetUDT
private DataTypeDescriptor targetUDT
The original, unbound descriptor for the target type, if it is a UDT.
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externallyGeneratedCastNode
private boolean externallyGeneratedCastNode
This variable gets set by the parser to indicate that this CAST node has been generated by the parser. This means that we should use the collation info of the current compilation schema for this node's collation setting. If this variable does not get set to true, then it means that this CAST node has been an internally generated node and we should not touch the collation info set for this CAST node because it has been already set correctly by the class that generated this CAST node. Collation info is part of the DataTypeDescriptor that's defined on the ValueNode (the super class of this CastNode class)
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assignmentSemantics
private boolean assignmentSemantics
Method calls: Argument type has the same semantics as assignment: Section 9.2 (Store assignment). There, General Rule 2.b.v.2 says that the database should raise an exception if truncation occurs when stuffing a string value into a VARCHAR, so make sure CAST doesn't issue warning only.
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udtTargetName
private TableName udtTargetName
The name of the target type if it's a UDT. It is partly redundant, as the name can also be retrieved from the type descriptor. Additionally, it contains information about the location of the UDT name in the query text, which is useful if the query text needs to be rewritten. (Useful for example when rewriting a CHECK constraint definition to have fully qualified names before storing it in the dictionary.) This field is only set for explicit casts to a UDT.
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Constructor Detail
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CastNode
CastNode(ValueNode castOperand, DataTypeDescriptor castTarget, ContextManager cm) throws StandardException
Constructor for a CastNode- Parameters:
castOperand
- The operand of the nodecastTarget
- DataTypeServices (target type of cast)cm
- The context manager- Throws:
StandardException
- Thrown on error
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CastNode
CastNode(ValueNode castOperand, int charType, int charLength, ContextManager cm) throws StandardException
Constructor for a CastNode- Parameters:
castOperand
- The operand of the nodecharType
- CHAR or VARCHAR JDBC type as targetcharLength
- target type lengthcm
- The context manager- Throws:
StandardException
- Thrown on error
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Method Detail
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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.
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printSubNodes
void printSubNodes(int depth)
Prints the sub-nodes of this object. See QueryTreeNode.java for how tree printing is supposed to work.- Overrides:
printSubNodes
in classQueryTreeNode
- Parameters:
depth
- The depth of this node in the tree
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getOrderableVariantType
protected int getOrderableVariantType() throws StandardException
Description copied from class:ValueNode
Return the variant type for the underlying expression. The variant type can be: VARIANT - variant within a scan (method calls and non-static field access) SCAN_INVARIANT - invariant within a scan (column references from outer tables) QUERY_INVARIANT - invariant within the life of a query (constant expressions)- Overrides:
getOrderableVariantType
in classValueNode
- Returns:
- The variant type for the underlying expression.
- Throws:
StandardException
- Thrown on error
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bindExpression
ValueNode bindExpression(FromList fromList, SubqueryList subqueryList, java.util.List<AggregateNode> aggregates) throws StandardException
Bind this expression. This means binding the sub-expressions, as well as figuring out what the return type is for this expression.- Overrides:
bindExpression
in classValueNode
- Parameters:
fromList
- The FROM list for the query this expression is in, for binding columns.subqueryList
- The subquery list being built as we find SubqueryNodesaggregates
- The aggregate list being built as we find AggregateNodes- Returns:
- The new top of the expression tree.
- Throws:
StandardException
- Thrown on error
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bindCastNodeOnly
void bindCastNodeOnly() throws StandardException
Bind this node but not its child. Caller has already bound the child. This is useful for when we generate a CastNode during binding after having already bound the child.- Throws:
StandardException
- Thrown on error
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getCastFromCharConstant
private ValueNode getCastFromCharConstant(int destJDBCTypeId) throws StandardException
Get a constant representing the cast from a CHAR to another type. If this is not an "easy" cast to perform, then just return this cast node. Here's what we think is "easy": source destination ------ ----------- char boolean char date/time/ts char non-decimal numeric- Parameters:
destJDBCTypeId
- The destination JDBC TypeId- Returns:
- The new top of the tree (this CastNode or a new Constant)
- Throws:
StandardException
- Thrown on error
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getCastFromIntegralType
private ValueNode getCastFromIntegralType(long longValue, int destJDBCTypeId) throws StandardException
Get a constant representing the cast from an integral type to another type. If this is not an "easy" cast to perform, then just return this cast node. Here's what we think is "easy": source destination ------ ----------- integral type non-decimal numeric integral type char- Parameters:
longValue
- integral type as a long to cast fromdestJDBCTypeId
- The destination JDBC TypeId- Returns:
- The new top of the tree (this CastNode or a new Constant)
- Throws:
StandardException
- Thrown on error
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getCastFromNumericType
private ValueNode getCastFromNumericType(DataValueDescriptor constantValue, int destJDBCTypeId) throws StandardException
Get a constant representing the cast from a non-integral type to another type. If this is not an "easy" cast to perform, then just return this cast node. Here's what we think is "easy": source destination ------ ----------- non-integral type non-decimal numeric non-integral type char- Parameters:
constantValue
- non-integral type a a double to cast fromdestJDBCTypeId
- The destination JDBC TypeId- Returns:
- The new top of the tree (this CastNode or a new Constant)
- Throws:
StandardException
- Thrown on error
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preprocess
ValueNode preprocess(int numTables, FromList outerFromList, SubqueryList outerSubqueryList, PredicateList outerPredicateList) throws StandardException
Preprocess an expression tree. We do a number of transformations here (including subqueries, IN lists, LIKE and BETWEEN) plus subquery flattening. NOTE: This is done before the outer ResultSetNode is preprocessed.- Overrides:
preprocess
in classValueNode
- Parameters:
numTables
- Number of tables in the DML StatementouterFromList
- FromList from outer query blockouterSubqueryList
- SubqueryList from outer query blockouterPredicateList
- PredicateList from outer query block- Returns:
- The modified expression
- Throws:
StandardException
- Thrown on error
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categorize
boolean categorize(JBitSet referencedTabs, boolean simplePredsOnly) throws StandardException
Categorize this predicate. Initially, this means building a bit map of the referenced tables for each predicate. If the source of this ColumnReference (at the next underlying level) is not a ColumnReference or a VirtualColumnNode then this predicate will not be pushed down. For example, in: select * from (select 1 from s) a (x) where x = 1 we will not push down x = 1. NOTE: It would be easy to handle the case of a constant, but if the inner SELECT returns an arbitrary expression, then we would have to copy that tree into the pushed predicate, and that tree could contain subqueries and method calls. RESOLVE - revisit this issue once we have views.- Overrides:
categorize
in classValueNode
- Parameters:
referencedTabs
- JBitSet with bit map of referenced FromTablessimplePredsOnly
- Whether or not to consider method calls, field references and conditional nodes when building bit map- Returns:
- boolean Whether or not source.expression is a ColumnReference or a VirtualColumnNode.
- Throws:
StandardException
- Thrown on error
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remapColumnReferencesToExpressions
ValueNode remapColumnReferencesToExpressions() throws StandardException
Remap all ColumnReferences in this tree to be clones of the underlying expression.- Overrides:
remapColumnReferencesToExpressions
in classValueNode
- Returns:
- ValueNode The remapped expression tree.
- Throws:
StandardException
- Thrown on error
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isConstantExpression
boolean isConstantExpression()
Return whether or not this expression tree represents a constant expression.- Overrides:
isConstantExpression
in classValueNode
- Returns:
- Whether or not this expression tree represents a constant expression.
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constantExpression
boolean constantExpression(PredicateList whereClause)
Description copied from class:ValueNode
Return whether or not this expression tree represents a constant value. In this case, "constant" means that it will always evaluate to the same thing, even if it includes columns. A column is constant if it is compared to a constant expression.- Overrides:
constantExpression
in classValueNode
- Returns:
- True means this expression tree represents a constant value.
- See Also:
ValueNode.constantExpression(org.apache.derby.impl.sql.compile.PredicateList)
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getConstantValueAsObject
java.lang.Object getConstantValueAsObject() throws StandardException
Return an Object representing the bind time value of this expression tree. If the expression tree does not evaluate to a constant at bind time then we return null. This is useful for bind time resolution of VTIs. RESOLVE: What do we do for primitives?- Overrides:
getConstantValueAsObject
in classValueNode
- Returns:
- An Object representing the bind time value of this expression tree. (null if not a bind time constant.)
- Throws:
StandardException
- Thrown on error
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generateExpression
void generateExpression(ExpressionClassBuilder acb, MethodBuilder mb) throws StandardException
Do code generation for this unary operator.- Overrides:
generateExpression
in classValueNode
- Parameters:
acb
- The ExpressionClassBuilder for the class we're generatingmb
- The method the code to place the code- Throws:
StandardException
- Thrown on error
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genDataValueConversion
private void genDataValueConversion(ExpressionClassBuilder acb, MethodBuilder mb) throws StandardException
- Throws:
StandardException
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acceptChildren
void acceptChildren(Visitor v) throws StandardException
Accept the visitor for all visitable children of this node.- Overrides:
acceptChildren
in classQueryTreeNode
- Parameters:
v
- the visitor- Throws:
StandardException
- on error
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setForExternallyGeneratedCASTnode
void setForExternallyGeneratedCASTnode()
This method gets called by the parser to indiciate that this CAST node has been generated by the parser. This means that we should use the collation info of the current compilation schmea for this node's collation setting. If this method does not get called, then it means that this CAST node has been an internally generated node and we should not touch the collation of this CAST node because it has been already set correctly by the class that generated this CAST node.
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setForDataTypeFunction
void setForDataTypeFunction(boolean b)
set this to be a dataTypeScalarFunction- Parameters:
b
- true to use function conversion rules
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setAssignmentSemantics
void setAssignmentSemantics()
Set assignmentSemantics to true. Used by method calls for casting actual arguments
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isEquivalent
boolean isEquivalent(ValueNode o) throws StandardException
Tests if this node is equivalent to the specified ValueNode. Two ValueNodes are considered equivalent if they will evaluate to the same value during query execution.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:
- The two ValueNodes must be of the same node type to be considered equivalent. e.g.: CastNode vs. CastNode - equivalent (if their args also match), ColumnReference vs CastNode - not equivalent.
- If node P contains other ValueNode(s) and so on, those node(s) must also be of the same node type to be considered equivalent.
- If node P takes a parameter list, then the number of arguments and its arguments for the two nodes must also match to be considered equivalent. e.g.: CAST(c1 as INTEGER) vs CAST(c1 as SMALLINT), they are not equivalent.
- When comparing SQL NULLs in this context, they are considered to be equivalent.
- If this does not apply or it is determined that the two nodes are not equivalent then the derived class of this method should return false; otherwise, return true.
- Specified by:
isEquivalent
in classValueNode
- Parameters:
o
- the node to compare this ValueNode against.- Returns:
true
if the two nodes are equivalent,false
otherwise.- Throws:
StandardException
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setTargetUDTName
void setTargetUDTName(TableName name)
Set the target type name if this is a cast to a UDT.- Parameters:
name
- the name of the target type
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