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

java.lang.Object
  org.apache.derby.impl.sql.compile.QueryTreeNode
      org.apache.derby.impl.sql.compile.StatementNode
          org.apache.derby.impl.sql.compile.DMLStatementNode

All Implemented Interfaces:

Visitable

Direct Known Subclasses:

CallStatementNode, DMLModStatementNode, ReadCursorNode

public abstract class DMLStatementNode

extends StatementNode

A DMLStatementNode represents any type of DML statement: a cursor declaration, an INSERT statement, and UPDATE statement, or a DELETE statement. All DML statements have result sets, but they do different things with them. A SELECT statement sends its result set to the client, an INSERT statement inserts its result set into a table, a DELETE statement deletes from a table the rows corresponding to the rows in its result set, and an UPDATE statement updates the rows in a base table corresponding to the rows in its result set.

Author:

Jeff Lichtman

Field Summary

ResultSetNode

resultSet The result set is the rows that result from running the statement.

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

DMLStatementNode()

Method Summary

Visitable	accept(Visitor v) Accept a visitor, and call v.visit() on child nodes as necessary.
(package private) int	activationKind() Returns the type of activation this class generates.
QueryTreeNode	bind(DataDictionary dataDictionary) Bind this DMLStatementNode.
protected void	bindExpressions() Bind the expressions in this DML statement.
protected void	bindExpressionsWithTables() Bind the expressions in the underlying ResultSets with tables.
QueryTreeNode	bindResultSetsWithTables(DataDictionary dataDictionary) Bind only the underlying ResultSets with tables.
protected void	bindTables(DataDictionary dataDictionary) Bind the tables in this DML statement.
(package private) void	generateParameterHolders(ActivationClassBuilder acb)
(package private) void	generateParameterValueSet(ActivationClassBuilder acb) Generate the code to create the ParameterValueSet, if necessary, when constructing the activation.
ResultSetNode	getResultSetNode() Get the ResultSetNode from this DML Statement.
void	init(java.lang.Object resultSet) Initializer for a DMLStatementNode
boolean	isAtomic() A read statement is atomic (DMLMod overrides us) if there are no work units, and no SELECT nodes, or if its SELECT nodes are all arguments to a function.
ResultDescription	makeResultDescription() Make a ResultDescription for use in a PreparedStatement.
QueryTreeNode	optimize() Optimize a DML statement (which is the only type of statement that should need optimizing, I think).
void	printSubNodes(int depth) Prints the sub-nodes of this object.

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

generate, lockTableForCompilation, statementToString, toString

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

bind, convertDefaultNode, debugFlush, debugPrint, executeSchemaName, executeStatementName, formatNodeString, foundString, generate, generateAuthorizeCheck, getBeginOffset, getClassFactory, getCompilerContext, getContextManager, getCursorInfo, getDataDictionary, getDependencyManager, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getIntProperty, getLanguageConnectionContext, getNodeFactory, getNodeType, getNullNode, getParameterTypes, getRowEstimate, getSchemaDescriptor, getSchemaDescriptor, getSPSName, getStatementType, getTableDescriptor, getTypeCompiler, init, init, init, init, init, init, init, init, init, init, init, init, init, isInstanceOf, isSessionSchema, isSessionSchema, makeConstantAction, makeTableName, needsSavepoint, nodeHeader, parseQueryText, printLabel, referencesSessionSchema, resolveTableToSynonym, setBeginOffset, setContextManager, setEndOffset, setNodeType, setRefActionInfo, treePrint, treePrint, verifyClassExist

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

resultSet

public ResultSetNode resultSet

The result set is the rows that result from running the statement. What this means for SELECT statements is fairly obvious. For a DELETE, there is one result column representing the key of the row to be deleted (most likely, the location of the row in the underlying heap). For an UPDATE, the row consists of the key of the row to be updated plus the updated columns. For an INSERT, the row consists of the new column values to be inserted, with no key (the system generates a key). The parser doesn't know anything about keys, so the columns representing the keys will be added after parsing (perhaps in the binding phase?). RESOLVE: This is public so RepDeleteNode can see it. Perhaps it should hava a public accessor function.

Constructor Detail

DMLStatementNode

public DMLStatementNode()

Method Detail

init

public void init(java.lang.Object resultSet)

Initializer for a DMLStatementNode

Overrides:

init in class QueryTreeNode

Parameters:

resultSet - A ResultSetNode for the result set of the DML statement

printSubNodes

public 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 class QueryTreeNode

Parameters:

depth - The depth of this node in the tree

Returns:

Nothing

getResultSetNode

public ResultSetNode getResultSetNode()

Get the ResultSetNode from this DML Statement. (Useful for view resolution after parsing the view definition.)

Returns:

ResultSetNode The ResultSetNode from this DMLStatementNode.

bind

public QueryTreeNode bind(DataDictionary dataDictionary)
                   throws StandardException

Bind this DMLStatementNode. 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.

Parameters:

dataDictionary - The DataDictionary to use to look up columns, tables, etc.

Returns:

The bound query tree

Throws:

StandardException - Thrown on error

bindResultSetsWithTables

public QueryTreeNode bindResultSetsWithTables(DataDictionary dataDictionary)
                                       throws StandardException

Bind only the underlying ResultSets with tables. This is necessary for INSERT, where the binding order depends on the underlying ResultSets. 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.

Parameters:

dataDictionary - The DataDictionary to use to look up columns, tables, etc.

Returns:

The bound query tree

Throws:

StandardException - Thrown on error

bindTables

protected void bindTables(DataDictionary dataDictionary)
                   throws StandardException

Bind the tables in this DML statement.

Parameters:

dataDictionary - The data dictionary to use to look up the tables

Returns:

Nothing

Throws:

StandardException - Thrown on error

bindExpressions

protected void bindExpressions()
                        throws StandardException

Bind the expressions in this DML statement.

Returns:

Nothing

Throws:

StandardException - Thrown on error

bindExpressionsWithTables

protected void bindExpressionsWithTables()
                                  throws StandardException

Bind the expressions in the underlying ResultSets with tables.

Returns:

Nothing

Throws:

StandardException - Thrown on error

activationKind

int activationKind()

Returns the type of activation this class generates.

Specified by:

activationKind in class StatementNode

Returns:

either (NEED_ROW_ACTIVATION | NEED_PARAM_ACTIVATION) or (NEED_ROW_ACTIVATION) depending on params

optimize

public QueryTreeNode optimize()
                       throws StandardException

Optimize a DML statement (which is the only type of statement that should need optimizing, I think). This method over-rides the one in QueryTreeNode. This method takes a bound tree, and returns an optimized tree. It annotates the bound tree rather than creating an entirely new tree. Throws an exception if the tree is not bound, or if the binding is out of date.

Overrides:

optimize in class QueryTreeNode

Returns:

An optimized QueryTree

Throws:

StandardException - Thrown on error

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 QueryTreeNode

Returns:

A ResultDescription for this DML statement

generateParameterValueSet

void generateParameterValueSet(ActivationClassBuilder acb)
                         throws StandardException

Generate the code to create the ParameterValueSet, if necessary, when constructing the activation. Also generate the code to call a method that will throw an exception if we try to execute without all the parameters being set.

Parameters:

acb - The ActivationClassBuilder for the class we're building

Returns:

Nothing

Throws:

StandardException

generateParameterHolders

void generateParameterHolders(ActivationClassBuilder acb)
                        throws StandardException

Throws:

StandardException

isAtomic

public boolean isAtomic()
                 throws StandardException

A read statement is atomic (DMLMod overrides us) if there are no work units, and no SELECT nodes, or if its SELECT nodes are all arguments to a function. This is admittedly a bit simplistic, what if someone has:

 	VALUES myfunc(SELECT max(c.commitFunc()) FROM T) 
 

but we aren't going too far out of our way to catch every possible wierd case. We basically want to be permissive w/o allowing someone to partially commit a write.

Overrides:

isAtomic in class StatementNode

Returns:

true if the statement is atomic

Throws:

StandardException - on error

accept

public Visitable accept(Visitor v)
                 throws StandardException

Accept a visitor, and call v.visit() on child nodes as necessary.

Specified by:

accept in interface Visitable

Overrides:

accept in class QueryTreeNode

Parameters:

v - the visitor

Throws:

StandardException - on error