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@ -60,10 +60,10 @@ SELECTION=u'σ'
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RENAME=u'ρ'
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ARROW=u'➡'
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b_operators=(u'*',u'-',u'ᑌ',u'ᑎ',u'÷',u'ᐅᐊ',u'ᐅLEFTᐊ',u'ᐅRIGHTᐊ',u'ᐅFULLᐊ') # List of binary operators
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u_operators=(u'π',u'σ',u'ρ') # List of unary operators
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b_operators=(PRODUCT,DIFFERENCE,UNION,INTERSECTION,DIVISION,JOIN,JOIN_LEFT,JOIN_RIGHT,JOIN_FULL) # List of binary operators
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u_operators=(PROJECTION,SELECTION,RENAME) # List of unary operators
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op_functions={u'*':'product',u'-':'difference',u'ᑌ':'union',u'ᑎ':'intersection',u'÷':'division',u'ᐅᐊ':'join',u'ᐅLEFTᐊ':'outer_left',u'ᐅRIGHTᐊ':'outer_right',u'ᐅFULLᐊ':'outer',u'π':'projection',u'σ':'selection',u'ρ':'rename'} # Associates operator with python method
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op_functions={PRODUCT:'product',DIFFERENCE:'difference',UNION:'union',INTERSECTION:'intersection',DIVISION:'division',JOIN:'join',JOIN_LEFT:'outer_left',JOIN_RIGHT:'outer_right',JOIN_FULL:'outer',PROJECTION:'projection',SELECTION:'selection',RENAME:'rename'} # Associates operator with python method
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class node (object):
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'''This class is a node of a relational expression. Leaves are relations and internal nodes are operations.
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@ -133,10 +133,10 @@ class node (object):
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prop =self.prop
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#Converting parameters
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if self.name==u'π':#Projection
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if self.name==PROJECTION:#Projection
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prop='\"%s\"' % prop.replace(' ','').replace(',','\",\"')
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elif self.name==u"ρ": #Rename
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prop='{\"%s\"}' % prop.replace(',','\",\"').replace('➡','\":\"').replace(' ','')
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prop='{\"%s\"}' % prop.replace(',','\",\"').replace(ARROW,'\":\"').replace(' ','')
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else: #Selection
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prop='\"%s\"' % prop
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@ -177,23 +177,23 @@ class node (object):
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if self.kind==RELATION:
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return list(rels[self.name].header.attributes)
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elif self.kind==BINARY and self.name in ('-','ᑌ','ᑎ'):
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elif self.kind==BINARY and self.name in (DIFFERENCE,UNION,INTERSECTION):
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return self.left.result_format(rels)
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elif self.kind==BINARY and self.name=='÷':
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elif self.kind==BINARY and self.name==DIVISION:
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return list(set(self.left.result_format(rels)) - set(self.right.result_format(rels)))
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elif self.name=='π':
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elif self.name==PROJECTION:
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l=[]
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for i in self.prop.split(','):
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l.append(i.strip())
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return l
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elif self.name=='*':
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elif self.name==PRODUCT:
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return self.left.result_format(rels)+self.right.result_format(rels)
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elif self.name=='σ':
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elif self.name==SELECTION:
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return self.child.result_format(rels)
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elif self.name=='ρ':
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elif self.name==RENAME:
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_vars={}
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for i in self.prop.split(','):
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q=i.split('➡')
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q=i.split(ARROW)
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_vars[q[0].strip()]=q[1].strip()
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_fields=self.child.result_format(rels)
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@ -201,7 +201,7 @@ class node (object):
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if _fields[i] in _vars:
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_fields[i]=_vars[_fields[i]]
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return _fields
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elif self.name in ('ᐅᐊ','ᐅLEFTᐊ','ᐅRIGHTᐊ','ᐅFULLᐊ'):
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elif self.name in (JOIN,JOIN_LEFT,JOIN_RIGHT,JOIN_FULL):
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return list(set(self.left.result_format(rels)).union(set(self.right.result_format(rels))))
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def __eq__(self,other):
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if not (isinstance(other,node) and self.name==other.name and self.kind==other.kind):
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LtWorf