Class StatementNode

java.lang.Object
org.apache.derby.impl.sql.compile.QueryTreeNode
org.apache.derby.impl.sql.compile.StatementNode
All Implemented Interfaces:
Visitable
Direct Known Subclasses:
DDLStatementNode, DMLStatementNode, ExecSPSNode, MiscellaneousStatementNode, NOPStatementNode, TransactionStatementNode

public abstract class StatementNode extends QueryTreeNode
A StatementNode represents a single statement in the language. It is the top node for any statement.

StatementNode controls the class generation for query tree nodes.

  • Field Details

    • EMPTY_TD_LIST

      static final TableDescriptor[] EMPTY_TD_LIST
      Cached empty list object.
    • NEED_DDL_ACTIVATION

      static final int NEED_DDL_ACTIVATION
      create the outer shell class builder for the class we will be generating, generate the expression to stuff in it, and turn it into a class.
      See Also:
    • NEED_CURSOR_ACTIVATION

      static final int NEED_CURSOR_ACTIVATION
      See Also:
    • NEED_PARAM_ACTIVATION

      static final int NEED_PARAM_ACTIVATION
      See Also:
    • NEED_ROW_ACTIVATION

      static final int NEED_ROW_ACTIVATION
      See Also:
    • NEED_NOTHING_ACTIVATION

      static final int NEED_NOTHING_ACTIVATION
      See Also:
  • Constructor Details

  • Method Details

    • isAtomic

      public boolean isAtomic() throws StandardException
      By default, assume StatementNodes are atomic. The rare statements that aren't atomic (e.g. CALL method()) override this.
      Overrides:
      isAtomic in class QueryTreeNode
      Returns:
      true if the statement is atomic
      Throws:
      StandardException - Thrown on error
    • needsSavepoint

      public boolean needsSavepoint()
      Returns whether or not this Statement requires a set/clear savepoint around its execution. The following statement "types" do not require them: Cursor - unnecessary and won't work in a read only environment Xact - savepoint will get blown away underneath us during commit/rollback

      ONLY CALLABLE AFTER GENERATION

      This implementation returns true, sub-classes can override the method to not require a savepoint.

      Returns:
      boolean Whether or not this Statement requires a set/clear savepoint
    • getSPSName

      public String getSPSName()
      Get the name of the SPS that is used to execute this statement. Only relevant for an ExecSPSNode -- otherwise, returns null.
      Returns:
      the name of the underlying sps
    • executeStatementName

      public String executeStatementName()
      Returns the name of statement in EXECUTE STATEMENT command. Returns null for all other commands.
      Returns:
      String null unless overridden for Execute Statement command
    • executeSchemaName

      public String executeSchemaName()
      Returns name of schema in EXECUTE STATEMENT command. Returns null for all other commands.
      Returns:
      String schema for EXECUTE STATEMENT null for all others
    • makeResultDescription

      public ResultDescription makeResultDescription()
      Only DML statements have result descriptions - for all others return null. This method is overridden in DMLStatementNode.
      Returns:
      null
    • getCursorInfo

      public Object getCursorInfo() throws StandardException
      Get an object with information about the cursor if there is one.
      Throws:
      StandardException
    • toString

      public 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 QueryTreeNode
      Returns:
      This object as a String
    • statementToString

      abstract String statementToString()
    • bindStatement

      public void bindStatement() throws StandardException
      Perform the binding operation statement. Binding consists of permissions checking, view resolution, datatype resolution, and creation of a dependency list (for determining whether a tree or plan is still up to date). This bindStatement() method does nothing. Each StatementNode type that can appear at the top of a tree can override this method with its own bindStatement() method that does "something".
      Throws:
      StandardException - Thrown on error
    • optimizeStatement

      public void optimizeStatement() throws StandardException
      Generates an optimized statement from a bound StatementNode. Actually, it annotates the tree in place rather than generating a new tree. For non-optimizable statements (for example, CREATE TABLE), return the bound tree without doing anything. For optimizable statements, this method will be over-ridden in the statement's root node (DMLStatementNode in all cases we know about so far). Throws an exception if the tree is not bound, or if the binding is out of date.
      Throws:
      StandardException - Thrown on error
    • activationKind

      abstract int activationKind()
    • lockTableForCompilation

      protected TableDescriptor lockTableForCompilation(TableDescriptor td) throws StandardException
      Throws:
      StandardException
    • generate

      public GeneratedClass generate(ByteArray byteCode) throws StandardException
      Do code generation for this statement.
      Parameters:
      byteCode - the generated byte code for this statement. if non-null, then the byte code is saved here.
      Returns:
      A GeneratedClass for this statement
      Throws:
      StandardException - Thrown on error
    • updateIndexStatisticsFor

      public TableDescriptor[] updateIndexStatisticsFor() throws StandardException
      Returns a list of base tables for which the index statistics of the associated indexes should be updated.

      This default implementation always returns an empty list.

      Returns:
      A list of table descriptors (potentially empty).
      Throws:
      StandardException - if accessing the index descriptors of a base table fails