[Modeling-cvs] ProjectModeling/Modeling/DatabaseAdaptors/MySQLAdaptorLayer MySQLSQLExpression.py,1.5,1.6

[<sbi...@us...>]

Update of /cvsroot/modeling/ProjectModeling/Modeling/DatabaseAdaptors/MySQLAdaptorLayer
In directory sc8-pr-cvs1:/tmp/cvs-serv21866/DatabaseAdaptors/MySQLAdaptorLayer

Modified Files:
	MySQLSQLExpression.py 
Log Message:
Fixed bug #780495: when ec.fetch() is joining two tables or more, the
returned set of objects could have duplicates.


Index: MySQLSQLExpression.py
===================================================================
RCS file: /cvsroot/modeling/ProjectModeling/Modeling/DatabaseAdaptors/MySQLAdaptorLayer/MySQLSQLExpression.py,v
retrieving revision 1.5
retrieving revision 1.6
diff -C2 -d -r1.5 -r1.6
*** MySQLSQLExpression.py	31 May 2003 15:12:24 -0000	1.5
--- MySQLSQLExpression.py	3 Aug 2003 10:34:14 -0000	1.6
***************
*** 173,174 ****
--- 173,272 ----
  
      return (str, aliases)
+ 
+   def prepareSelectCountExpressionWithAttributes(self,
+                                                  attributes,lock,fetchSpec):
+     """
+     Overrides the default method and prepares a SQL expression suitable for
+     MySQL, counting the rows qualified by 'fetchSpec'.
+ 
+     The SQL statement depends on whether 'fetchSpec' implies joining two or
+     more tables:
+ 
+       - if at least a join is needed, the statement is like::
+ 
+           SELECT COUNT(DISTINCT t0.pk1, t0.pk2, ...) FROM ...
+           INNER JOIN ...
+           [WHERE <fetchSpec's condition>]
+ 
+         where pk1, pk2 are the primary keys in the fetchSpec's entity,
+ 
+       - otherwise, it is like:
+ 
+           SELECT COUNT(*) FROM <table> [WHERE <fetchSpec's condition>]
+ 
+     Parameters:
+ 
+       attributes -- the attributes to fetch (they do not appear in the sql)
+ 
+       lock -- Unimplemented, should be false
+ 
+       fetchSpec -- the FetchSpecification qualifying the rows to be counted
+ 
+     """
+     self.setUseAliases('Yep')
+     lockClause=''
+     if lock:
+       raise NotImplementedError, 'lock is not implemented yet'
+     
+     for attribute in attributes:
+       self.addSelectListAttribute(attribute)
+ 
+     # fetchSpec
+     if fetchSpec is not None and \
+        self._entity.restrictingQualifier() is not None: # TBD
+       raise 'Unimplemented', \
+             "fetchSpec and/or entity's restrictingQualifier is not None"
+ 
+     # qualifier: to be mixed w/ entity's restrictingQualifier if necessary
+     fullQualifier=None
+ 
+     fsQualifier=fetchSpec and fetchSpec.qualifier() or None
+     entityQual=self._entity.restrictingQualifier()
+     if fsQualifier:
+       if entityQual:
+         fullQualifier=AndQualifier([fsQualifier, entityQual])
+       else:
+         fullQualifier=fsQualifier
+     elif entityQual:
+       fullQualifier=entityQual
+ 
+     # clause: WHERE
+     self._whereClauseString=self.sqlStringForQualifier(fullQualifier)
+ 
+     joinClause=''
+     
+     # Do we join some tables?
+     multiple_tables_joined=len(self.entityExternalNamesByAliases())>1
+     selectString=''
+ 
+     columnList=' COUNT(*) '
+     if multiple_tables_joined:
+       columnList='COUNT(DISTINCT '
+       # TBD: cf. test_14: if we use this:
+       #self._internals.aliasForEntityExternalName(self._entity.externalName())
+       # then we select from the wrong table (t3 instead of t0)
+       entity_alias='t0'
+       for pk in self._entity.primaryKeyAttributes():
+         columnList+=entity_alias+'.'+pk.columnName()+', '
+       columnList=columnList[:-2]+') '
+     else:
+       columnList=' COUNT(*) '
+         
+     fetchOrder=None
+     whereClause=self.whereClauseString()
+     # orderBy: see fetchSpec...
+     orderByClause=''
+ 
+     #
+     tableList=self.tableListWithRootEntity(self.entity())
+     self.assembleSelectStatementWithAttributes(attributes=attributes,
+                                                lock=lock,
+                                                qualifier=fullQualifier,
+                                                fetchOrder=fetchOrder,
+                                                selectString=selectString,
+                                                columnList=columnList,
+                                                tableList=tableList,
+                                                whereClause=whereClause,
+                                                joinClause=joinClause,
+                                                orderByClause=orderByClause,
+                                                lockClause=lockClause)