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, CursorNode, DMLModStatementNode
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.

  • Field Details

    • resultSet

      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?).

  • Constructor Details

  • Method Details

    • printSubNodes

      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

    • getResultSetNode

      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

      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

      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
      Throws:
      StandardException - Thrown on error

    • bindExpressions

      protected void bindExpressions() throws StandardException
      Bind the expressions in this DML statement.
      Throws:
      StandardException - Thrown on error

    • bindExpressionsWithTables

      protected void bindExpressionsWithTables() throws StandardException
      Bind the expressions in the underlying ResultSets with tables.
      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

    • optimizeStatement

      public void optimizeStatement() 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:
      optimizeStatement in class StatementNode
      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 StatementNode
      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
      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

    • acceptChildren

      void acceptChildren(Visitor v) throws StandardException
      Accept the visitor for all visitable children of this node.
      Overrides:
      acceptChildren in class QueryTreeNode
      Parameters:
      v - the visitor
      Throws:
      StandardException - on error

    • getPrivType

      int getPrivType()
      Return default privilege needed for this node. Other DML nodes can override this method to set their own default privilege.
      Returns:
      true if the statement is atomic