UserTypeConstantNode (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.impl.sql.compile.QueryTreeNode
- - org.apache.derby.impl.sql.compile.ValueNode
  - - org.apache.derby.impl.sql.compile.ConstantNode
    - - org.apache.derby.impl.sql.compile.UserTypeConstantNode

All Implemented Interfaces:

Visitable
```
class UserTypeConstantNode
extends ConstantNode
```
User type constants. These are created by built-in types that use user types as their implementation. This could also potentially be used by an optimizer that wanted to store plans for frequently-used parameter values. This is also used to represent nulls in user types, which occurs when NULL is inserted into or supplied as the update value for a user type column.

Field Summary

Fields
Modifier and Type Field Description

(package private) java.lang.Object val
- Fields inherited from class org.apache.derby.impl.sql.compile.ConstantNode
  value
- 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
- Fields inherited from class org.apache.derby.impl.sql.compile.ValueNode
  transformed

Fields
Modifier and Type	Field	Description
`(package private) java.lang.Object`	`val`

Constructor Summary

Constructors
Constructor	Description
`UserTypeConstantNode(java.sql.Date d, ContextManager cm)`
`UserTypeConstantNode(java.sql.Time t, ContextManager cm)`
`UserTypeConstantNode(java.sql.Timestamp t, ContextManager cm)`
`UserTypeConstantNode(DataValueDescriptor dvd, ContextManager cm)`
`UserTypeConstantNode(TypeId t, ContextManager cm)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`(package private) void`	`generateConstant(ExpressionClassBuilder acb, MethodBuilder mb)`	Should never be called for UserTypeConstantNode because we have our own generateExpression().
`(package private) void`	`generateExpression(ExpressionClassBuilder acb, MethodBuilder mb)`	For a UserTypeConstantNode, we have to store away the object somewhere and have a way to get it back at runtime.
`(package private) java.lang.Object`	`getConstantValueAsObject()`	Return an Object representing the bind time value of this expression tree.
`java.lang.Object`	`getObjectValue()`	Return the object value of this user defined type.
`private static TypeId`	`getTypeId(DataValueDescriptor dvd)`
`private static int`	`getWidth(DataValueDescriptor dvd)`
`(package private) boolean`	`isNull()`	Return whether or not this node represents a typed null constant.

Methods inherited from class org.apache.derby.impl.sql.compile.ConstantNode
bindExpression, constantExpression, getClone, getOrderableVariantType, getValue, isCloneable, isConstantExpression, isEquivalent, setValue, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode
accept, acceptChildren, 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, printSubNodes, referencesSessionSchema, resolveTableToSynonym, setBeginOffset, setEndOffset, setRefActionInfo, stackPrint, taggedWith, treePrint, treePrint, verifyClassExist

Methods inherited from class org.apache.derby.impl.sql.compile.ValueNode
bindExpression, categorize, changeToCNF, checkIsBoolean, checkTopPredicatesForEqualsConditions, copyFields, eliminateNots, evaluateConstantExpressions, genEqualsFalseTree, generate, genIsNullTree, genSQLJavaSQLTree, getColumnName, getDataValueFactory, getSchemaName, getSourceResultColumn, getTableName, getTablesReferenced, getTransformed, getTypeCompiler, getTypeId, getTypeServices, isBinaryEqualsOperatorNode, isBooleanFalse, isBooleanTrue, isInListProbeNode, isParameterNode, isRelationalOperator, isSameNodeKind, optimizableEqualityNode, preprocess, putAndsOnTop, remapColumnReferencesToExpressions, requiresTypeFromContext, selectivity, setCollationInfo, setCollationInfo, setCollationUsingCompilationSchema, setCollationUsingCompilationSchema, setNullability, setTransformed, setType, setType, setType, updatableByCursor, verifyChangeToCNF, verifyEliminateNots, verifyPutAndsOnTop

- Field Detail
  - val
```
java.lang.Object val
```
- Constructor Detail
  - UserTypeConstantNode
```
UserTypeConstantNode(TypeId t,
                     ContextManager cm)
              throws StandardException
```
    Throws:
    
    StandardException
  - UserTypeConstantNode
```
UserTypeConstantNode(java.sql.Date d,
                     ContextManager cm)
              throws StandardException
```
    Throws:
    
    StandardException
  - UserTypeConstantNode
```
UserTypeConstantNode(java.sql.Time t,
                     ContextManager cm)
              throws StandardException
```
    Throws:
    
    StandardException
  - UserTypeConstantNode
```
UserTypeConstantNode(java.sql.Timestamp t,
                     ContextManager cm)
              throws StandardException
```
    Throws:
    
    StandardException
  - UserTypeConstantNode
```
UserTypeConstantNode(DataValueDescriptor dvd,
                     ContextManager cm)
              throws StandardException
```
    Parameters:
    
    dvd - Must contain a Date, Time or Timestamp value
    
    cm - context manager
    
    Throws:
    
    StandardException
- Method Detail
  - getTypeId
```
private static TypeId getTypeId(DataValueDescriptor dvd)
```
  - getWidth
```
private static int getWidth(DataValueDescriptor dvd)
```
  - getObjectValue
```
public java.lang.Object getObjectValue()
```
    Return the object value of this user defined type.
    
    Returns:
    
    the value of this constant. can't use getValue() for this. getValue() returns the DataValueDescriptor for the built-in types that are implemented as user types (date, time, timestamp)
  - isNull
```
boolean isNull()
```
    Return whether or not this node represents a typed null constant.
    
    Overrides:
    
    isNull in class ConstantNode
  - getConstantValueAsObject
```
java.lang.Object getConstantValueAsObject()
```
    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 class ValueNode
    
    Returns:
    
    An Object representing the bind time value of this expression tree. (null if not a bind time constant.)
  - generateExpression
```
void generateExpression(ExpressionClassBuilder acb,
                        MethodBuilder mb)
                 throws StandardException
```
    For a UserTypeConstantNode, we have to store away the object somewhere and have a way to get it back at runtime. These objects are serializable. This gives us at least two options: 1) serialize it out into a byte array field, and serialize it back in when needed, from the field. 2) have an array of objects in the prepared statement and a #, to find the object directly. Because it is serializable, it will store with the rest of the executable just fine. Choice 2 gives better performance -- the ser/deser cost is paid on database access for the statement, not for each execution of it. However, it requires some infrastructure support from prepared statements. For now, we take choice 3, and make some assumptions about available methods on the user type. This choice has the shortcoming that it will not work for arbitrary user types. REVISIT and implement choice 2 when a general solution is needed.
    A null is generated as a Null value cast to the type of the constant node.
    
    Overrides:
    
    generateExpression in class ConstantNode
    
    Parameters:
    
    acb - The ExpressionClassBuilder for the class being built
    
    mb - The method the expression will go into
    
    Throws:
    
    StandardException - Thrown on error
  - generateConstant
```
void generateConstant(ExpressionClassBuilder acb,
                      MethodBuilder mb)
               throws StandardException
```
    Should never be called for UserTypeConstantNode because we have our own generateExpression().
    
    Specified by:
    
    generateConstant in class ConstantNode
    
    Parameters:
    
    acb - The ExpressionClassBuilder for the class being built
    
    mb - The method the expression will go into
    
    Throws:
    
    StandardException - Thrown on error

Class UserTypeConstantNode

Field Summary

Fields inherited from class org.apache.derby.impl.sql.compile.ConstantNode

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

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

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

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

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

Field Detail

val

Constructor Detail

UserTypeConstantNode

UserTypeConstantNode

UserTypeConstantNode

UserTypeConstantNode

UserTypeConstantNode

Method Detail

getTypeId

getWidth

getObjectValue

isNull

getConstantValueAsObject

generateExpression

generateConstant