org.makumba.providers.query.mql
Class QueryContext

java.lang.Object
  org.makumba.providers.query.mql.QueryContext

public class QueryContext
extends Object

FROM analysis code. Each query/subquery has its own QueryContext. This is ported from the old OQL parser. Additions: 1) look in the parent query context for labels unknown here 2) more than just LEFT JOIN is supported

Version:

$Id: QueryContext.java,v 1.1 Aug 5, 2008 5:50:39 PM cristi Exp $

Author:

Cristian Bogdan

Nested Class Summary

(package private) class

QueryContext.Join the four elements of a join: label1.field1 = label2.field2

Field Summary

(package private) Hashtable<String,String>	aliases support aliases in query
(package private) DataDefinitionProvider	ddp
(package private) HashSet<String>	explicitLabels labels defined explicitly in the FROM section of this subquery
(package private) Vector<NameResolver.TextList>	filters correlation conditions
(package private) Hashtable<String,DataDefinition>	fromLabels labels explicitly defined in OQL FROM
(package private) MqlNode	inTree
(package private) Hashtable<String,String>	joinNames finder for joins in the form label.field, used in order not to repeat the same join
(package private) Vector<QueryContext.Join>	joins the joins needed out of the label.field from this query
(package private) LinkedHashMap<String,DataDefinition>	labels associate each label to its makumba type
(package private) Hashtable<String,MqlNode>	projectionLabelSearch searcher for projection labels
(package private) MqlSqlWalker	walker

Constructor Summary

QueryContext(MqlSqlWalker mqlSqlWalker)

Method Summary

void	addFrom(String frm, antlr.collections.AST labelAST, int joinType)
(package private) String	addJoin(String l1, String f1, String name, String f2, DataDefinition type, int joinType, antlr.collections.AST location) make a new join with the name and associate the label with the type
void	close()
antlr.collections.AST	createFromElement(String path, antlr.collections.AST alias, int joinType)
(package private) DataDefinition	findLabelType(String label)
(package private) String	getFieldName(String label, String field, NameResolver nr) return the database-level name of the given field of the given label
LinkedHashMap<String,DataDefinition>	getLabels()
QueryContext	getParent()
Hashtable<String,MqlNode>	getProjectionLabelSearch()
(package private) DataDefinition	getTableName(String label) return the database-level name of the type of the given label
(package private) String	join(String label, String field, String labelf, int joinType, antlr.collections.AST location) produce a new label out of label.field, with the indicated labelf name for the result check if the indicated field exists in the type of the label determine the type of the result label if more joins are necesary inbetween (e.g. for sets), add these joins as well
void	selectField(String label, String field, MqlDotNode mqlDotNode)
NameResolver.TextList	selectLabel(String label, MqlNode node)
void	setParent(QueryContext currentContext)
protected void	writeFrom(NameResolver.TextList ret) writes the iterator definitions (FROM part)
protected void	writeJoins(NameResolver.TextList ret) write the translator-generated joins

Methods inherited from class java.lang.Object

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

Field Detail

walker

MqlSqlWalker walker

ddp

DataDefinitionProvider ddp

inTree

MqlNode inTree

labels

LinkedHashMap<String,DataDefinition> labels

associate each label to its makumba type

fromLabels

Hashtable<String,DataDefinition> fromLabels

labels explicitly defined in OQL FROM

aliases

Hashtable<String,String> aliases

support aliases in query

joins

Vector<QueryContext.Join> joins

the joins needed out of the label.field from this query

joinNames

Hashtable<String,String> joinNames

finder for joins in the form label.field, used in order not to repeat the same join

projectionLabelSearch

Hashtable<String,MqlNode> projectionLabelSearch

searcher for projection labels

filters

Vector<NameResolver.TextList> filters

correlation conditions

explicitLabels

HashSet<String> explicitLabels

labels defined explicitly in the FROM section of this subquery

Constructor Detail

QueryContext

public QueryContext(MqlSqlWalker mqlSqlWalker)

Method Detail

setParent

public void setParent(QueryContext currentContext)

getParent

public QueryContext getParent()

createFromElement

public antlr.collections.AST createFromElement(String path,
                                               antlr.collections.AST alias,
                                               int joinType)
                                        throws antlr.SemanticException

Throws:

antlr.SemanticException

close

public void close()

addJoin

String addJoin(String l1,
               String f1,
               String name,
               String f2,
               DataDefinition type,
               int joinType,
               antlr.collections.AST location)
         throws antlr.SemanticException

make a new join with the name and associate the label with the type

Parameters:

joinType -

location -

Throws:

antlr.SemanticException

join

String join(String label,
            String field,
            String labelf,
            int joinType,
            antlr.collections.AST location)
      throws antlr.SemanticException

produce a new label out of label.field, with the indicated labelf name for the result check if the indicated field exists in the type of the label determine the type of the result label if more joins are necesary inbetween (e.g. for sets), add these joins as well

Parameters:

joinType -

-

Throws:

antlr.SemanticException

addFrom

public void addFrom(String frm,
                    antlr.collections.AST labelAST,
                    int joinType)
             throws antlr.SemanticException

Throws:

antlr.SemanticException

findLabelType

DataDefinition findLabelType(String label)

writeFrom

protected void writeFrom(NameResolver.TextList ret)

writes the iterator definitions (FROM part)

getTableName

DataDefinition getTableName(String label)

return the database-level name of the type of the given label

getFieldName

String getFieldName(String label,
                    String field,
                    NameResolver nr)

return the database-level name of the given field of the given label

writeJoins

protected void writeJoins(NameResolver.TextList ret)

write the translator-generated joins

selectLabel

public NameResolver.TextList selectLabel(String label,
                                         MqlNode node)

selectField

public void selectField(String label,
                        String field,
                        MqlDotNode mqlDotNode)
                 throws antlr.SemanticException

Throws:

antlr.SemanticException

getProjectionLabelSearch

public Hashtable<String,MqlNode> getProjectionLabelSearch()

getLabels

public LinkedHashMap<String,DataDefinition> getLabels()