org.apache.derby.impl.sql.compile

Class UpdateNode

java.lang.Object

org.apache.derby.impl.sql.compile.QueryTreeNode

org.apache.derby.impl.sql.compile.StatementNode

org.apache.derby.impl.sql.compile.UpdateNode

All Implemented Interfaces:

Visitable

public final class UpdateNode
extends StatementNode

An UpdateNode represents an UPDATE statement. It is the top node of the query tree for that statement. For positioned update, there may be no from table specified. The from table will be derived from the cursor specification of the named cursor.

Field Summary

Fields

Modifier and Type	Field and Description
long[]	indexConglomerateNumbers
java.lang.String[]	indexNames
IndexRowGenerator[]	indicesToMaintain

Method Summary

Modifier and Type	Method and Description
void	bindStatement() Bind this UpdateNode.
MethodBuilder	generateCheckConstraints(ValueNode checkConstraints, org.apache.derby.impl.sql.compile.ExpressionClassBuilder ecb) Generate a method to evaluate a tree of CHECK CONSTRAINTS.
void	generateCheckConstraints(ValueNode checkConstraints, org.apache.derby.impl.sql.compile.ExpressionClassBuilder ecb, MethodBuilder mb) Generate the code to evaluate a tree of CHECK CONSTRAINTS.
void	generateGenerationClauses(org.apache.derby.impl.sql.compile.ResultColumnList rcl, int resultSetNumber, boolean isUpdate, org.apache.derby.impl.sql.compile.ExpressionClassBuilder ecb, MethodBuilder mb) Generate the code to evaluate all of the generation clauses.
boolean	inMatchingClause() Returns true if this DMLModStatement a [ NOT ] MATCHED action of a MERGE statement
boolean	isAtomic() INSERT/UPDATE/DELETE are always atomic.
ConstantAction	makeConstantAction() Compile constants that Execution will use
ResultDescription	makeResultDescription() Make a ResultDescription for use in a PreparedStatement.
void	optimizeStatement() Generate an optimized QueryTree from a bound QueryTree.
ValueNode	parseCheckConstraint(java.lang.String checkConstraintText, TableDescriptor td) Parse a check constraint and turn it into a query tree.
ValueNode	parseGenerationClause(java.lang.String clauseText, TableDescriptor td) Parse the generation clause for a column.
boolean	referencesSessionSchema() Return true if the node references SESSION schema tables (temporary or permanent)
java.lang.String	toString() Convert this object to a String.

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

executeSchemaName, executeStatementName, generate, getCursorInfo, getSPSName, needsSavepoint, updateIndexStatisticsFor

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

accept, addTag, bindOffsetFetch, bindRowMultiSet, bindUserCatalogType, bindUserType, checkReliability, checkReliability, createTypeDependency, getBeginOffset, getDataDictionary, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getOffsetOrderedNodes, getOptimizerFactory, getOptimizerTracer, getParameterTypes, getUDTDesc, makeTableName, makeTableName, optimizerTracingIsOn, orReliability, setBeginOffset, setEndOffset, taggedWith, treePrint

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

indicesToMaintain

public IndexRowGenerator[] indicesToMaintain

indexConglomerateNumbers

public long[] indexConglomerateNumbers

indexNames

public java.lang.String[] indexNames

Method Detail

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.

Overrides:

toString in class StatementNode

Returns:

This object as a String

bindStatement

public void bindStatement()
                   throws StandardException

Bind this UpdateNode. 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.

Binding an update will also massage the tree so that the ResultSetNode has a set of columns to contain the old row value, followed by a set of columns to contain the new row value, followed by a column to contain the RowLocation of the row to be updated.

Overrides:

bindStatement in class StatementNode

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

inMatchingClause

public boolean inMatchingClause()

Returns true if this DMLModStatement a [ NOT ] MATCHED action of a MERGE statement

isAtomic

public boolean isAtomic()

INSERT/UPDATE/DELETE are always atomic.

Returns:

true

parseGenerationClause

public ValueNode parseGenerationClause(java.lang.String clauseText,
                                       TableDescriptor td)
                                throws StandardException

Parse the generation clause for a column.

Parameters:

clauseText - Text of the generation clause

Returns:

The parsed expression as a query tree.

Throws:

StandardException - Thrown on failure

parseCheckConstraint

public ValueNode parseCheckConstraint(java.lang.String checkConstraintText,
                                      TableDescriptor td)
                               throws StandardException

Parse a check constraint and turn it into a query tree.

Parameters:

checkConstraintText - Text of CHECK CONSTRAINT.

td - The TableDescriptor for the table the the constraint is on.

Returns:

The parsed check constraint as a query tree.

Throws:

StandardException - Thrown on failure

generateCheckConstraints

public void generateCheckConstraints(ValueNode checkConstraints,
                                     org.apache.derby.impl.sql.compile.ExpressionClassBuilder ecb,
                                     MethodBuilder mb)
                              throws StandardException

Generate the code to evaluate a tree of CHECK CONSTRAINTS.

Parameters:

checkConstraints - Bound query tree of ANDed check constraints.

ecb - Expression Class Builder

Throws:

StandardException - Thrown on error

generateCheckConstraints

public MethodBuilder generateCheckConstraints(ValueNode checkConstraints,
                                              org.apache.derby.impl.sql.compile.ExpressionClassBuilder ecb)
                                       throws StandardException

Generate a method to evaluate a tree of CHECK CONSTRAINTS.

Parameters:

checkConstraints - Bound query tree of ANDed check constraints.

ecb - Expression Class Builder

Throws:

StandardException - Thrown on error

generateGenerationClauses

public void generateGenerationClauses(org.apache.derby.impl.sql.compile.ResultColumnList rcl,
                                      int resultSetNumber,
                                      boolean isUpdate,
                                      org.apache.derby.impl.sql.compile.ExpressionClassBuilder ecb,
                                      MethodBuilder mb)
                               throws StandardException

Generate the code to evaluate all of the generation clauses. If there are generation clauses, this routine builds an Activation method which evaluates the generation clauses and fills in the computed columns.

Parameters:

rcl - describes the row of expressions to be put into the bas table

resultSetNumber - index of base table into array of ResultSets

isUpdate - true if this is for an UPDATE statement

ecb - code generation state variable

mb - the method being generated

Throws:

StandardException - Thrown on error

optimizeStatement

public void optimizeStatement()
                       throws StandardException

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.

Throws:

StandardException - Thrown on failure

makeResultDescription

public ResultDescription makeResultDescription()

Make a ResultDescription for use in a PreparedStatement. ResultDescriptions are visible to JDBC only for cursor statements. For other types of statements, they are only used internally to get descriptions of the base tables being affected. For example, for an INSERT statement, the ResultDescription describes the rows in the table being inserted into, which is useful when the values being inserted are of a different type or length than the columns in the base table.

Overrides:

makeResultDescription in class StatementNode

Returns:

A ResultDescription for this DML statement