com.metamatrix.query.resolver.util
Class ResolverUtil

java.lang.Object
  com.metamatrix.query.resolver.util.ResolverUtil

public class ResolverUtil
extends java.lang.Object

Utilities used during resolution

Nested Class Summary

static class

ResolverUtil.ResolvedLookup

Method Summary

static TempMetadataID	addTempGroup(TempMetadataAdapter metadata, GroupSymbol symbol, java.util.List symbols, boolean tempTable)
static void	addTempTable(TempMetadataAdapter metadata, GroupSymbol symbol, java.util.List symbols)
static boolean	canImplicitlyConvert(java.lang.String fromType, java.lang.String toType) Gets whether there exists an implicit conversion from the source type to the target type
static Constant	convertConstant(java.lang.String sourceTypeName, java.lang.String targetTypeName, Constant constant)
static Expression	convertExpression(Expression sourceExpression, java.lang.String targetTypeName) Replaces a sourceExpression with a conversion of the source expression to the target type.
static Expression	convertExpression(Expression sourceExpression, java.lang.String sourceTypeName, java.lang.String targetTypeName) Replaces a sourceExpression with a conversion of the source expression to the target type.
static java.util.List	findMatchingGroups(java.lang.String groupContext, java.util.Collection groups, QueryMetadataInterface metadata)
static java.util.List	getAccessPatternElementsInGroups(QueryMetadataInterface metadata, java.util.Collection groups, boolean flatten) When access patterns are flattened, they are an approximation the user may need to enter as criteria.
static java.lang.String	getCommonType(java.lang.String[] typeNames) Gets the most specific type to which all the given types have an implicit conversion.
static Expression	getDefault(ElementSymbol symbol, QueryMetadataInterface metadata) Get the default value for the parameter, which could be null if the parameter is set to NULLABLE.
static boolean	orderByContainsVariable(OrderBy orderBy, SingleElementSymbol ses, int position) Checks if a variable is in the ORDER BY
static java.util.List	resolveElements(GroupSymbol group, QueryMetadataInterface metadata, java.util.List elementIDs)
static java.util.List<ElementSymbol>	resolveElementsInGroup(GroupSymbol group, QueryMetadataInterface metadata) Returns the resolved elements in the given group.
static void	resolveGroup(GroupSymbol symbol, QueryMetadataInterface metadata)
static void	resolveImplicitTempGroup(TempMetadataAdapter metadata, GroupSymbol symbol, java.util.List symbols)
static void	resolveLimit(Limit limit)
static ResolverUtil.ResolvedLookup	resolveLookup(Function lookup, QueryMetadataInterface metadata)
static void	resolveNullLiterals(java.util.List symbols) Look for a null literal in the SELECT clause and set it's type to STRING.
static void	resolveOrderBy(OrderBy orderBy, java.util.List fromClauseGroups, java.util.List knownElements, QueryMetadataInterface metadata, boolean isSimpleQuery) Attempt to resolve the order by throws QueryResolverException if the symbol is not of SingleElementSymbol type
static void	setDesiredType(Expression expression, java.lang.Class<?> targetType, LanguageObject surroundingExpression) Utility to set the type of an expression if it is a Reference and has a null type.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getCommonType

public static java.lang.String getCommonType(java.lang.String[] typeNames)

Gets the most specific type to which all the given types have an implicit conversion. The method decides a common type as follows:

• If one or more of the given types is a candidate, then this method will return the candidate that occurs first in the given array. This is why the order of the names in the array is important.
• Otherwise, if none of them is a candidate, this method will attempt to find a common type to which all of them can be implicitly converted.
• Otherwise this method is unable to find a common type to which all the given types can be implicitly converted, and therefore returns a null.

Parameters:

typeNames - an ordered array of unique type names.

Returns:

a type name to which all the given types can be converted

canImplicitlyConvert

public static boolean canImplicitlyConvert(java.lang.String fromType,
                                           java.lang.String toType)

Gets whether there exists an implicit conversion from the source type to the target type

Parameters:

fromType -

toType -

Returns:

true if there exists an implicit conversion from the fromType to the toType.

convertExpression

public static Expression convertExpression(Expression sourceExpression,
                                           java.lang.String targetTypeName)
                                    throws QueryResolverException

Replaces a sourceExpression with a conversion of the source expression to the target type. If the source type and target type are the same, this method does nothing.

Parameters:

sourceExpression -

targetTypeName -

Returns:

Throws:

QueryResolverException

convertExpression

public static Expression convertExpression(Expression sourceExpression,
                                           java.lang.String sourceTypeName,
                                           java.lang.String targetTypeName)
                                    throws QueryResolverException

Replaces a sourceExpression with a conversion of the source expression to the target type. If the source type and target type are the same, this method does nothing.

Parameters:

sourceExpression -

sourceTypeName -

targetTypeName -

Returns:

Throws:

QueryResolverException

convertConstant

public static Constant convertConstant(java.lang.String sourceTypeName,
                                       java.lang.String targetTypeName,
                                       Constant constant)

setDesiredType

public static void setDesiredType(Expression expression,
                                  java.lang.Class<?> targetType,
                                  LanguageObject surroundingExpression)
                           throws QueryResolverException

Utility to set the type of an expression if it is a Reference and has a null type.

Parameters:

expression - the expression to test

targetType - the target type, if the expression's type is null.

Throws:

QueryResolverException - if unable to set the reference type to the target type.

resolveOrderBy

public static void resolveOrderBy(OrderBy orderBy,
                                  java.util.List fromClauseGroups,
                                  java.util.List knownElements,
                                  QueryMetadataInterface metadata,
                                  boolean isSimpleQuery)
                           throws QueryResolverException,
                                  QueryMetadataException,
                                  MetaMatrixComponentException

Attempt to resolve the order by throws QueryResolverException if the symbol is not of SingleElementSymbol type

Parameters:

orderBy -

fromClauseGroups - groups of the FROM clause of the query (for resolving ambiguous unqualified element names), or empty List if a Set Query Order By is being resolved

knownElements - resolved elements from SELECT clause, which are only ones allowed to be in ORDER BY

metadata - QueryMetadataInterface

isSimpleQuery -

Throws:

QueryResolverException

QueryMetadataException

MetaMatrixComponentException

getDefault

public static Expression getDefault(ElementSymbol symbol,
                                    QueryMetadataInterface metadata)
                             throws MetaMatrixComponentException,
                                    QueryMetadataException,
                                    QueryResolverException

Get the default value for the parameter, which could be null if the parameter is set to NULLABLE. If no default is available, a QueryResolverException will be thrown.

Parameters:

symbol - ElementSymbol retrieved from metadata, fully-resolved

metadata - QueryMetadataInterface

Returns:

expr param (if it is non-null) or default value (if there is one) or null Constant (if parameter is optional and therefore allows this)

Throws:

QueryResolverException - if expr is null, parameter is required and no default value is defined

QueryMetadataException - for error retrieving metadata

MetaMatrixComponentException

Since:

4.3

resolveElementsInGroup

public static java.util.List<ElementSymbol> resolveElementsInGroup(GroupSymbol group,
                                                                   QueryMetadataInterface metadata)
                                                            throws QueryMetadataException,
                                                                   MetaMatrixComponentException

Returns the resolved elements in the given group. This method has the side effect of caching the resolved elements on the group object. The resolved elements may not contain non-selectable columns depending on the metadata first used for resolving.

Throws:

QueryMetadataException

MetaMatrixComponentException

resolveElements

public static java.util.List resolveElements(GroupSymbol group,
                                             QueryMetadataInterface metadata,
                                             java.util.List elementIDs)
                                      throws MetaMatrixComponentException,
                                             QueryMetadataException

Throws:

MetaMatrixComponentException

QueryMetadataException

getAccessPatternElementsInGroups

public static java.util.List getAccessPatternElementsInGroups(QueryMetadataInterface metadata,
                                                              java.util.Collection groups,
                                                              boolean flatten)
                                                       throws MetaMatrixComponentException,
                                                              QueryMetadataException

When access patterns are flattened, they are an approximation the user may need to enter as criteria.

Parameters:

metadata -

groups -

flatten -

Returns:

Throws:

MetaMatrixComponentException

QueryMetadataException

resolveLimit

public static void resolveLimit(Limit limit)
                         throws QueryResolverException

Throws:

QueryResolverException

resolveImplicitTempGroup

public static void resolveImplicitTempGroup(TempMetadataAdapter metadata,
                                            GroupSymbol symbol,
                                            java.util.List symbols)
                                     throws MetaMatrixComponentException,
                                            QueryResolverException

Throws:

MetaMatrixComponentException

QueryResolverException

addTempGroup

public static TempMetadataID addTempGroup(TempMetadataAdapter metadata,
                                          GroupSymbol symbol,
                                          java.util.List symbols,
                                          boolean tempTable)
                                   throws QueryResolverException

Throws:

QueryResolverException

addTempTable

public static void addTempTable(TempMetadataAdapter metadata,
                                GroupSymbol symbol,
                                java.util.List symbols)
                         throws QueryResolverException

Throws:

QueryResolverException

resolveNullLiterals

public static void resolveNullLiterals(java.util.List symbols)

Look for a null literal in the SELECT clause and set it's type to STRING. This ensures that the result set metadata retrieved for this query will be properly set to something other than the internal NullType. Added for defect 15437.

Parameters:

select - The select clause

Since:

4.2

findMatchingGroups

public static java.util.List findMatchingGroups(java.lang.String groupContext,
                                                java.util.Collection groups,
                                                QueryMetadataInterface metadata)
                                         throws MetaMatrixComponentException,
                                                QueryMetadataException

Parameters:

groupContext -

groups -

metadata -

Returns:

the List of groups that match the given groupContext out of the supplied collection

Throws:

MetaMatrixComponentException

QueryMetadataException

orderByContainsVariable

public static boolean orderByContainsVariable(OrderBy orderBy,
                                              SingleElementSymbol ses,
                                              int position)

Checks if a variable is in the ORDER BY

Parameters:

position - 0-based index of the variable

Returns:

True if the ORDER BY contains the element

resolveLookup

public static ResolverUtil.ResolvedLookup resolveLookup(Function lookup,
                                                        QueryMetadataInterface metadata)
                                                 throws QueryResolverException,
                                                        MetaMatrixComponentException

Throws:

QueryResolverException

MetaMatrixComponentException

resolveGroup

public static void resolveGroup(GroupSymbol symbol,
                                QueryMetadataInterface metadata)
                         throws MetaMatrixComponentException,
                                QueryResolverException

Throws:

MetaMatrixComponentException

QueryResolverException