org.eigenbase.sql
Class SqlSetOperator

java.lang.Object
  org.eigenbase.sql.SqlOperator
      org.eigenbase.sql.SqlBinaryOperator
          org.eigenbase.sql.SqlSetOperator

public class SqlSetOperator
extends SqlBinaryOperator

SqlSetOperator represents a relational set theory operator (UNION, INTERSECT, MINUS). These are binary operators, but with an extra boolean attribute tacked on for whether to remove duplicates (e.g. UNION ALL does not remove duplicates).

Version:

$Id: //open/dev/farrago/src/org/eigenbase/sql/SqlSetOperator.java#16 $

Author:

John V. Sichi

Field Summary

private boolean

all

Fields inherited from class org.eigenbase.sql.SqlOperator

MaxPrec, NL

Constructor Summary

SqlSetOperator(String name, SqlKind kind, int prec, boolean all)

SqlSetOperator(String name, SqlKind kind, int prec, boolean all, SqlReturnTypeInference returnTypeInference, SqlOperandTypeInference operandTypeInference, SqlOperandTypeChecker operandTypeChecker)

Method Summary

boolean	isAll()
boolean	isDistinct()
void	validateCall(SqlCall call, SqlValidator validator, SqlValidatorScope scope, SqlValidatorScope operandScope) Validates a call to this operator.

Methods inherited from class org.eigenbase.sql.SqlBinaryOperator

adjustType, deriveType, getMonotonicity, getSignatureTemplate, getSyntax, needsSpace

Methods inherited from class org.eigenbase.sql.SqlOperator

acceptCall, acceptCall, argumentMustBeScalar, checkOperandCount, checkOperandTypes, createCall, createCall, createCall, createCall, equals, getAllowedSignatures, getAllowedSignatures, getKind, getLeftPrec, getName, getOperandCountRange, getOperandTypeChecker, getOperandTypeInference, getReturnTypeInference, getRightPrec, hashCode, inferReturnType, inferReturnType, isAggregator, isDeterministic, isDynamicFunction, isName, leftPrec, preValidateCall, requiresDecimalExpansion, rewriteCall, rightPrec, toString, unparse, unparseListClause, unparseListClause, validateOperands

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

all

private final boolean all

Constructor Detail

SqlSetOperator

public SqlSetOperator(String name,
                      SqlKind kind,
                      int prec,
                      boolean all)

SqlSetOperator

public SqlSetOperator(String name,
                      SqlKind kind,
                      int prec,
                      boolean all,
                      SqlReturnTypeInference returnTypeInference,
                      SqlOperandTypeInference operandTypeInference,
                      SqlOperandTypeChecker operandTypeChecker)

Method Detail

isAll

public boolean isAll()

isDistinct

public boolean isDistinct()

validateCall

public void validateCall(SqlCall call,
                         SqlValidator validator,
                         SqlValidatorScope scope,
                         SqlValidatorScope operandScope)

Description copied from class: SqlOperator

Validates a call to this operator.

This method should not perform type-derivation or perform validation related related to types. That is done later, by SqlOperator.deriveType(SqlValidator, SqlValidatorScope, SqlCall). This method should focus on structural validation.

A typical implementation of this method first validates the operands, then performs some operator-specific logic. The default implementation just validates the operands.

This method is the default implementation of SqlCall.validate(org.eigenbase.sql.validate.SqlValidator, org.eigenbase.sql.validate.SqlValidatorScope); but note that some sub-classes of SqlCall never call this method.

Overrides:

validateCall in class SqlOperator

Parameters:

call - the call to this operator

validator - the active validator

scope - validator scope

operandScope - validator scope in which to validate operands to this call; usually equal to scope, but not always because some operators introduce new scopes

See Also:

SqlNode.validateExpr(SqlValidator, SqlValidatorScope), SqlOperator.deriveType(SqlValidator, SqlValidatorScope, SqlCall)