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""" |
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Useful auxilliary data structures for query construction. Not useful outside |
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the SQL domain. |
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""" |
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class EmptyResultSet(Exception): |
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pass |
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class FullResultSet(Exception): |
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pass |
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class MultiJoin(Exception): |
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""" |
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Used by join construction code to indicate the point at which a |
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multi-valued join was attempted (if the caller wants to treat that |
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exceptionally). |
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""" |
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def __init__(self, level): |
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self.level = level |
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class Empty(object): |
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pass |
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class RawValue(object): |
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def __init__(self, value): |
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self.value = value |
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class Date(object): |
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""" |
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Add a date selection column. |
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""" |
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def __init__(self, col, lookup_type): |
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self.col = col |
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self.lookup_type = lookup_type |
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def relabel_aliases(self, change_map): |
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c = self.col |
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if isinstance(c, (list, tuple)): |
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self.col = (change_map.get(c[0], c[0]), c[1]) |
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def as_sql(self, qn, connection): |
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if isinstance(self.col, (list, tuple)): |
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col = '%s.%s' % tuple([qn(c) for c in self.col]) |
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else: |
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col = self.col |
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return connection.ops.date_trunc_sql(self.lookup_type, col) |