public abstract Class BinaryComparisonOperatorNode

Constructor for a BinaryComparisonOperatorNode

Parameters

leftOperand:ValueNode

The left operand of the comparison

rightOperand:ValueNode

The right operand of the comparison

operator:String

The name of the operator

methodName:String

The name of the method to call in the generated class

forQueryRewrite:boolean

Can be true only if if this node has been added by an internal rewrite of the query. This allows binding to be more liberal when checking it against allowed syntax. This parameter will be passed FALSE when a new instance of the node is being created(which is the majority of the cases). But when an existing node is getting cloned, the value of this parameter should be passed as the originalNode.getForQueryRewrite(). Examples of this can be found in Predicate.Java and PredicateList.java

cm:ContextManager

The context manager

Test the type compatability of the operands and set the type info for this node. This method is useful both during binding and when we generate nodes within the language module outside of the parser.

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.BinaryOperatorNode.bindExpression.

Bind this comparison operator. All that has to be done for binding a comparison operator is to bind the operands, check the compatibility of the types, and set the result type to SQLBoolean.

Parameters

fromList:FromList

The query's FROM list

subqueryList:SubqueryList

The subquery list being built as we find SubqueryNodes

aggregates:List<AggregateNode>

The aggregate list being built as we find AggregateNodes

Returns:ValueNode

The new top of the expression tree.

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ValueNode.changeToCNF.

Finish putting an expression into conjunctive normal form. An expression tree in conjunctive normal form meets the following criteria: o If the expression tree is not null, the top level will be a chain of AndNodes terminating in a true BooleanConstantNode. o The left child of an AndNode will never be an AndNode. o Any right-linked chain that includes an AndNode will be entirely composed of AndNodes terminated by a true BooleanConstantNode. o The left child of an OrNode will never be an OrNode. o Any right-linked chain that includes an OrNode will be entirely composed of OrNodes terminated by a false BooleanConstantNode. o ValueNodes other than AndNodes and OrNodes are considered leaf nodes for purposes of expression normalization. In other words, we won't do any normalization under those nodes. In addition, we track whether or not we are under a top level AndNode. SubqueryNodes need to know this for subquery flattening.

Parameters

underTopAndNode:boolean

Whether or not we are under a top level AndNode.

Returns:ValueNode

The modified expression

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.ValueNode.eliminateNots.

Eliminate NotNodes in the current query block. We traverse the tree, inverting ANDs and ORs and eliminating NOTs as we go. We stop at ComparisonOperators and boolean expressions. We invert ComparisonOperators and replace boolean expressions with boolean expression = false.

Parameters

underNotNode:boolean

Whether or not we are under a NotNode.

Returns:ValueNode

The modified expression

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Overrides org.apache.derby.impl.sql.compile.BinaryOperatorNode.genSQLJavaSQLTree.

Doc from org.apache.derby.impl.sql.compile.BinaryOperatorNode.genSQLJavaSQLTree.

generate a SQL->Java->SQL conversion tree above the left and right operand of this Binary Operator Node if needed. Subclasses can override the default behavior.

Returns:ValueNode

Doc from org.apache.derby.impl.sql.compile.ValueNode.genSQLJavaSQLTree.

ValueNode The new tree.

Annotations

@Override

Exceptions

StandardException:

Doc from org.apache.derby.impl.sql.compile.ValueNode.genSQLJavaSQLTree.

Thrown on error

See Also

BinaryOperatorNode#genSQLJavaSQLTree

Return whether or not to use the between selectivity for this node.

Returns:boolean

Whether or not to use the between selectivity for this node.

Was this node generated in a query rewrite?

Returns:boolean

true if it was generated in a query rewrite.

Negate the comparison.

Parameters

leftOperand:ValueNode

The left operand of the comparison operator

rightOperand:ValueNode

The right operand of the comparison operator

Returns:BinaryOperatorNode

BinaryOperatorNode The negated expression

Exceptions

StandardException:

Thrown on error

Return a node equivalent to this node, but with the left and right operands swapped. The node type may also be changed if the operator is not symmetric.

This method may for instance be used to normalize a predicate by moving constants to the right-hand side of the comparison. Example: 1 = A will be transformed to A = 1, and 10 < B will be transformed to B > 10.

Returns:BinaryOperatorNode

an equivalent expression with the operands swapped

Exceptions

StandardException:

if an error occurs

Overrides org.apache.derby.impl.sql.compile.BinaryOperatorNode.preprocess.

Preprocess an expression tree. We do a number of transformations here (including subqueries, IN lists, LIKE and BETWEEN) plus subquery flattening.

Parameters

numTables:int

Number of tables in the DML Statement

outerFromList:FromList

FromList from outer query block

outerSubqueryList:SubqueryList

SubqueryList from outer query block

outerPredicateList:PredicateList

PredicateList from outer query block

Returns:ValueNode

The modified expression

Annotations

@Override

Exceptions

StandardException:

Thrown on error

Use between selectivity when calculating the selectivity.

This node was generated as part of a query rewrite. Bypass the normal comparability checks.

Parameters

val:boolean

true if this was for a query rewrite