org.apache.derby.impl.sql.compile
Class DeleteNode

java.lang.Object
  extended byorg.apache.derby.impl.sql.compile.QueryTreeNode
      extended byorg.apache.derby.impl.sql.compile.StatementNode
          extended byorg.apache.derby.impl.sql.compile.DMLStatementNode
              extended byorg.apache.derby.impl.sql.compile.DMLModStatementNode
                  extended byorg.apache.derby.impl.sql.compile.DeleteNode
All Implemented Interfaces:
Visitable

public class DeleteNode
extends DMLModStatementNode

A DeleteNode represents a DELETE statement. It is the top-level node for the statement. For positioned delete, there may be no from table specified. The from table will be derived from the cursor specification of the named cursor.

Author:
Jeff Lichtman

Field Summary
private  boolean cascadeDelete
           
static java.lang.String COLUMNNAME
           
protected  boolean deferred
           
private  ConstantAction[] dependentConstantActions
           
private  QueryTreeNode[] dependentNodes
           
protected  ExecRow emptyHeapRow
           
protected  FKInfo fkInfo
           
protected  FormatableBitSet readColsBitSet
           
protected  FromTable targetTable
           
 
Fields inherited from class org.apache.derby.impl.sql.compile.DMLModStatementNode
fkColArrays, fkColDescriptors, fkIndexConglomNumbers, fkRefActions, fkTableNames, graphHashTable, indexConglomerateNumbers, indexNames, indicesToMaintain, isDependentTable, lockMode, relevantCdl, relevantTriggers, resultColumnList, targetTableDescriptor, targetTableName, targetVTI, triggerInfo
 
Fields inherited from class org.apache.derby.impl.sql.compile.DMLStatementNode
resultSet
 
Fields inherited from class org.apache.derby.impl.sql.compile.StatementNode
NEED_CURSOR_ACTIVATION, NEED_DDL_ACTIVATION, NEED_NOTHING_ACTIVATION, NEED_PARAM_ACTIVATION, NEED_ROW_ACTIVATION
 
Fields inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode
AUTOINCREMENT_INC_INDEX, AUTOINCREMENT_IS_AUTOINCREMENT_INDEX, AUTOINCREMENT_START_INDEX, beginOffset, endOffset
 
Constructor Summary
DeleteNode()
           
 
Method Summary
 QueryTreeNode bind()
          Bind this DeleteNode.
 void generate(ActivationClassBuilder acb, MethodBuilder mb)
          Code generation for delete.
private static FormatableBitSet getDeleteReadMap(TableDescriptor baseTable, java.util.Vector conglomVector, GenericDescriptorList relevantTriggers, boolean[] needsDeferredProcessing)
          Builds a bitmap of all columns which should be read from the Store in order to satisfy an DELETE statement. 1) finds all indices on this table 2) adds the index columns to a bitmap of affected columns 3) adds the index descriptors to a list of conglomerate descriptors. 4) finds all DELETE triggers on the table 5) if there are any DELETE triggers, marks all columns in the bitmap 6) adds the triggers to an evolving list of triggers
private  QueryTreeNode getDependentTableNode(java.lang.String tableName, int refAction, ColumnDescriptorList cdl)
          In case of referential actions, we require to perform DML (UPDATE or DELETE) on the dependent tables.
private  QueryTreeNode getEmptyDeleteNode(java.lang.String schemaName, java.lang.String targetTableName)
           
private  QueryTreeNode getEmptyUpdateNode(java.lang.String schemaName, java.lang.String targetTableName, ColumnDescriptorList cdl)
           
 FormatableBitSet getReadMap(DataDictionary dd, TableDescriptor baseTable)
          Gets the map of all columns which must be read out of the base table.
private  ResultColumnList getSetClause(TableName tabName, ColumnDescriptorList cdl)
           
protected  int getStatementType()
          Return the type of statement, something from StatementType.
 void init(java.lang.Object targetTableName, java.lang.Object queryExpression)
          Initializer for a DeleteNode.
 ConstantAction makeConstantAction()
          Compile constants that Execution will use
 QueryTreeNode optimize()
          Generate an optimized QueryTree from a bound QueryTree.
 boolean referencesSessionSchema()
          Return true if the node references SESSION schema tables (temporary or permanent)
 java.lang.String statementToString()
           
 
Methods inherited from class org.apache.derby.impl.sql.compile.DMLModStatementNode
adjustDeferredFlag, bindCheckConstraint, bindConstraints, generateCheckConstraints, generateCheckConstraints, generateCodeForTemporaryTable, getAffectedIndexes, getAllRelevantConstraints, getAllRelevantTriggers, getCheckConstraints, getFKInfo, getReadColMap, getResultColumnList, getResultColumnList, getSchemaDescriptor, getTriggerInfo, getXAffectedIndexes, hasCheckConstraints, init, isAtomic, markAffectedIndexes, parseCheckConstraint, requiresDeferredProcessing, setRefActionInfo, setTarget, verifyTargetTable
 
Methods inherited from class org.apache.derby.impl.sql.compile.DMLStatementNode
accept, activationKind, bind, bindExpressions, bindExpressionsWithTables, bindResultSetsWithTables, bindTables, generateParameterHolders, generateParameterValueSet, getResultSetNode, makeResultDescription, printSubNodes
 
Methods inherited from class org.apache.derby.impl.sql.compile.StatementNode
generate, lockTableForCompilation, toString
 
Methods inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode
convertDefaultNode, debugFlush, debugPrint, executeSchemaName, executeStatementName, formatNodeString, foundString, generateAuthorizeCheck, getBeginOffset, getClassFactory, getCompilerContext, getContextManager, getCursorInfo, getDataDictionary, getDependencyManager, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getIntProperty, getLanguageConnectionContext, getNodeFactory, getNodeType, getNullNode, getParameterTypes, getRowEstimate, getSchemaDescriptor, getSchemaDescriptor, getSPSName, getTableDescriptor, getTypeCompiler, init, init, init, init, init, init, init, init, init, init, init, init, isInstanceOf, isSessionSchema, isSessionSchema, makeTableName, needsSavepoint, nodeHeader, parseQueryText, printLabel, resolveTableToSynonym, setBeginOffset, setContextManager, setEndOffset, setNodeType, treePrint, treePrint, verifyClassExist
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

COLUMNNAME

public static final java.lang.String COLUMNNAME
See Also:
Constant Field Values

deferred

protected boolean deferred

emptyHeapRow

protected ExecRow emptyHeapRow

targetTable

protected FromTable targetTable

fkInfo

protected FKInfo fkInfo

readColsBitSet

protected FormatableBitSet readColsBitSet

dependentConstantActions

private ConstantAction[] dependentConstantActions

cascadeDelete

private boolean cascadeDelete

dependentNodes

private QueryTreeNode[] dependentNodes
Constructor Detail

DeleteNode

public DeleteNode()
Method Detail

init

public void init(java.lang.Object targetTableName,
                 java.lang.Object queryExpression)
Initializer for a DeleteNode.

Overrides:
init in class DMLModStatementNode
Parameters:
targetTableName - The name of the table to delete from
queryExpression - used by nodes that allocate a DMLMod directly (rather than inheriting it).

statementToString

public java.lang.String statementToString()
Overrides:
statementToString in class DMLModStatementNode

bind

public QueryTreeNode bind()
                   throws StandardException
Bind this DeleteNode. This means looking up tables and columns and getting their types, and figuring out the result types of all expressions, as well as doing view resolution, permissions checking, etc.

If any indexes need to be updated, we add all the columns in the base table to the result column list, so that we can use the column values as look-up keys for the index rows to be deleted. Binding a delete will also massage the tree so that the ResultSetNode has column containing the RowLocation of the base row.

Overrides:
bind in class QueryTreeNode
Returns:
The bound query tree
Throws:
StandardException - Thrown on error

referencesSessionSchema

public boolean referencesSessionSchema()
                                throws StandardException
Return true if the node references SESSION schema tables (temporary or permanent)

Overrides:
referencesSessionSchema in class QueryTreeNode
Returns:
true if references SESSION schema tables, else false
Throws:
StandardException - Thrown on error

makeConstantAction

public ConstantAction makeConstantAction()
                                  throws StandardException
Compile constants that Execution will use

Overrides:
makeConstantAction in class QueryTreeNode
Throws:
StandardException - Thrown on failure

generate

public void generate(ActivationClassBuilder acb,
                     MethodBuilder mb)
              throws StandardException
Code generation for delete. The generated code will contain: o A static member for the (xxx)ResultSet with the RowLocations o The static member will be assigned the appropriate ResultSet within the nested calls to get the ResultSets. (The appropriate cast to the (xxx)ResultSet will be generated.) o The CurrentRowLocation() in SelectNode's select list will generate a new method for returning the RowLocation as well as a call to that method which will be stuffed in the call to the ProjectRestrictResultSet. o In case of referential actions, this function generate an array of resultsets on its dependent tables.

Overrides:
generate in class QueryTreeNode
Parameters:
acb - The ActivationClassBuilder for the class being built
mb - The execute() method to be built
Throws:
StandardException - Thrown on error

getStatementType

protected final int getStatementType()
Return the type of statement, something from StatementType.

Overrides:
getStatementType in class QueryTreeNode
Returns:
the type of statement

getReadMap

public FormatableBitSet getReadMap(DataDictionary dd,
                                   TableDescriptor baseTable)
                            throws StandardException
Gets the map of all columns which must be read out of the base table. These are the columns needed to: o maintain indices o maintain foreign keys The returned map is a FormatableBitSet with 1 bit for each column in the table plus an extra, unsued 0-bit. If a 1-based column id must be read from the base table, then the corresponding 1-based bit is turned ON in the returned FormatableBitSet.

Parameters:
dd - the data dictionary to look in
baseTable - the base table descriptor
Returns:
a FormatableBitSet of columns to be read out of the base table
Throws:
StandardException - Thrown on error

getDependentTableNode

private QueryTreeNode getDependentTableNode(java.lang.String tableName,
                                            int refAction,
                                            ColumnDescriptorList cdl)
                                     throws StandardException
In case of referential actions, we require to perform DML (UPDATE or DELETE) on the dependent tables. Following function returns the DML Node for the dependent table.

Throws:
StandardException

getEmptyDeleteNode

private QueryTreeNode getEmptyDeleteNode(java.lang.String schemaName,
                                         java.lang.String targetTableName)
                                  throws StandardException
Throws:
StandardException

getEmptyUpdateNode

private QueryTreeNode getEmptyUpdateNode(java.lang.String schemaName,
                                         java.lang.String targetTableName,
                                         ColumnDescriptorList cdl)
                                  throws StandardException
Throws:
StandardException

getSetClause

private ResultColumnList getSetClause(TableName tabName,
                                      ColumnDescriptorList cdl)
                               throws StandardException
Throws:
StandardException

optimize

public QueryTreeNode optimize()
                       throws StandardException
Description copied from class: DMLModStatementNode
Generate an optimized QueryTree from a bound QueryTree. Actually, it can annotate the tree in place rather than generate a new tree, but this interface allows the root node of the optimized QueryTree to be different from the root node of the bound QueryTree. For non-optimizable statements, this method is a no-op. Throws an exception if the tree is not bound, or if the binding is out of date.

Overrides:
optimize in class DMLModStatementNode
Returns:
An optimized QueryTree
Throws:
StandardException - Thrown on failure

getDeleteReadMap

private static FormatableBitSet getDeleteReadMap(TableDescriptor baseTable,
                                                 java.util.Vector conglomVector,
                                                 GenericDescriptorList relevantTriggers,
                                                 boolean[] needsDeferredProcessing)
                                          throws StandardException
Builds a bitmap of all columns which should be read from the Store in order to satisfy an DELETE statement. 1) finds all indices on this table 2) adds the index columns to a bitmap of affected columns 3) adds the index descriptors to a list of conglomerate descriptors. 4) finds all DELETE triggers on the table 5) if there are any DELETE triggers, marks all columns in the bitmap 6) adds the triggers to an evolving list of triggers

Parameters:
conglomVector - OUT: vector of affected indices
relevantTriggers - IN/OUT. Passed in as an empty list. Filled in as we go.
needsDeferredProcessing - IN/OUT. true if the statement already needs deferred processing. set while evaluating this routine if a trigger requires deferred processing
Returns:
a FormatableBitSet of columns to be read out of the base table
Throws:
StandardException - Thrown on error

Built on Tue 2006-10-10 19:23:47+0200, from revision exported

Apache Derby V10.1 Engine Documentation - Copyright © 1997,2005 The Apache Software Foundation or its licensors, as applicable.