Constructor Detail

• GetCurrentConnectionNode

  GetCurrentConnectionNode​(ContextManager cm)

  Constructor for a GetCurrentConnectionNode

Method Detail

• bindExpression

  JavaValueNode bindExpression​(FromList fromList,
                               SubqueryList subqueryList,
                               java.util.List<AggregateNode> aggregates)
                        throws StandardException

  Bind this operator

  Specified by:

  bindExpression in class JavaValueNode

  Parameters:

  fromList - The query's FROM list

  subqueryList - The subquery list being built as we find SubqueryNodes

  aggregates - The aggregate list being built as we find AggregateNodes

  Returns:

  the new node, usually this

  Throws:

  StandardException - Thrown on error

  See Also:

  ValueNode.bindExpression(org.apache.derby.impl.sql.compile.FromList, org.apache.derby.impl.sql.compile.SubqueryList, java.util.List<org.apache.derby.impl.sql.compile.AggregateNode>)

• preprocess

  void preprocess​(int numTables,
                  FromList outerFromList,
                  SubqueryList outerSubqueryList,
                  PredicateList outerPredicateList)
           throws StandardException

  Preprocess an expression tree. We do a number of transformations here (including subqueries, IN lists, LIKE and BETWEEN) plus subquery flattening. NOTE: This is done before the outer ResultSetNode is preprocessed.

  Specified by:

  preprocess in class JavaValueNode

  Parameters:

  numTables - Number of tables in the DML Statement

  outerFromList - FromList from outer query block

  outerSubqueryList - SubqueryList from outer query block

  outerPredicateList - PredicateList from outer query block

  Throws:

  StandardException - Thrown on error

  See Also:

  ValueNode.preprocess(int, org.apache.derby.impl.sql.compile.FromList, org.apache.derby.impl.sql.compile.SubqueryList, org.apache.derby.impl.sql.compile.PredicateList)

• categorize

  boolean categorize​(JBitSet referencedTabs,
                     boolean simplePredsOnly)

  Categorize this predicate. Initially, this means building a bit map of the referenced tables for each predicate. If the source of this ColumnReference (at the next underlying level) is not a ColumnReference or a VirtualColumnNode then this predicate will not be pushed down. For example, in: select * from (select 1 from s) a (x) where x = 1 we will not push down x = 1. NOTE: It would be easy to handle the case of a constant, but if the inner SELECT returns an arbitrary expression, then we would have to copy that tree into the pushed predicate, and that tree could contain subqueries and method calls. RESOLVE - revisit this issue once we have views.

  Specified by:

  categorize in class JavaValueNode

  Parameters:

  referencedTabs - JBitSet with bit map of referenced FromTables

  simplePredsOnly - Whether or not to consider method calls, field references and conditional nodes when building bit map

  Returns:

  boolean Whether or not source.expression is a ColumnReference or a VirtualColumnNode.

  See Also:

  ValueNode.categorize(org.apache.derby.iapi.util.JBitSet, boolean)

• remapColumnReferencesToExpressions

  JavaValueNode remapColumnReferencesToExpressions()

  Remap all ColumnReferences in this tree to be clones of the underlying expression.

  Specified by:

  remapColumnReferencesToExpressions in class JavaValueNode

  Returns:

  JavaValueNode The remapped expression tree.

  See Also:

  ValueNode.remapColumnReferencesToExpressions()

• bindParameter

  void bindParameter()

  Bind a ? parameter operand of the char_length function.

• getOrderableVariantType

  int getOrderableVariantType()

  Return the variant type for the underlying expression. The variant type can be: VARIANT - variant within a scan (method calls and non-static field access) SCAN_INVARIANT - invariant within a scan (column references from outer tables) QUERY_INVARIANT - invariant within the life of a query (constant expressions)

  Overrides:

  getOrderableVariantType in class JavaValueNode

  Returns:

  The variant type for the underlying expression.

• generateExpression

  void generateExpression​(ExpressionClassBuilder acb,
                          MethodBuilder mb)
                   throws StandardException

  Description copied from class: JavaValueNode
  General logic shared by Core compilation and by the Replication Filter compiler. Every child of ValueNode must implement one of these methods.

  Specified by:

  generateExpression in class JavaValueNode

  Parameters:

  acb - The ExpressionClassBuilder for the class being built

  mb - The method the code to place the code

  Throws:

  StandardException - Thrown on error

  See Also:

  ConstantNode.generateExpression(org.apache.derby.impl.sql.compile.ExpressionClassBuilder, org.apache.derby.iapi.services.compiler.MethodBuilder)

• checkReliability

  void checkReliability​(ValueNode sqlNode)
                 throws StandardException

  Check the reliability type of this java value.

  Overrides:

  checkReliability in class JavaValueNode

  Throws:

  StandardException - Thrown on error

  See Also:

  CompilerContext