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2211
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aaronmk
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# SQL code generation
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2276
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aaronmk
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import operator
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2360
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aaronmk
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import objects
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2222
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aaronmk
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import strings
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2227
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aaronmk
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import util
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2211
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aaronmk
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2499
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aaronmk
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##### Escaping
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def esc_name(name, quote='"'):
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return quote + name.replace(quote, quote+quote) + quote
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# doubling an embedded quote escapes it in both PostgreSQL and MySQL
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2513
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aaronmk
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def clean_name(name): return name.replace('"', '').replace('`', '')
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2219
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aaronmk
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##### SQL code objects
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2349
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aaronmk
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class MockDb:
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2503
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aaronmk
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def esc_value(self, value): return strings.repr_no_u(value)
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2349
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aaronmk
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2499
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aaronmk
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def esc_name(self, name): return esc_name(name)
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2349
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aaronmk
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mockDb = MockDb()
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2514
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aaronmk
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class BasicObject(objects.BasicObject):
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def __init__(self, value): self.value = value
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def __str__(self): return clean_name(strings.repr_no_u(self))
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class Code(BasicObject):
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2211
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aaronmk
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def to_str(self, db): raise NotImplemented()
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2349
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aaronmk
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2514
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aaronmk
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def __repr__(self): return self.to_str(mockDb)
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2211
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aaronmk
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2269
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aaronmk
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class CustomCode(Code):
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2256
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aaronmk
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def __init__(self, str_): self.str_ = str_
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def to_str(self, db): return self.str_
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2335
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aaronmk
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##### Literal values
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2216
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aaronmk
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class Literal(Code):
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2211
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aaronmk
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def __init__(self, value): self.value = value
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2213
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aaronmk
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def to_str(self, db): return db.esc_value(self.value)
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2211
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aaronmk
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2400
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aaronmk
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def as_Value(value):
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if isinstance(value, Code): return value
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else: return Literal(value)
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2216
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aaronmk
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def is_null(value): return isinstance(value, Literal) and value.value == None
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2335
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aaronmk
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##### Tables
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2211
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aaronmk
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class Table(Code):
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def __init__(self, name, schema=None):
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'''
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@param schema str|None (for no schema)
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'''
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self.name = name
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self.schema = schema
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2348
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aaronmk
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def to_str(self, db):
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str_ = ''
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if self.schema != None: str_ += db.esc_name(self.schema)+'.'
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str_ += db.esc_name(self.name)
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return str_
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2336
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aaronmk
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def to_Table(self): return self
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2211
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aaronmk
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2219
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aaronmk
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def as_Table(table):
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2270
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aaronmk
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if table == None or isinstance(table, Code): return table
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2219
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aaronmk
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else: return Table(table)
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2336
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aaronmk
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class NamedTable(Table):
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def __init__(self, name, code, cols=None):
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Table.__init__(self, name)
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if not isinstance(code, Code): code = Table(code)
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self.code = code
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self.cols = cols
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def to_str(self, db):
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2467
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aaronmk
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str_ = self.code.to_str(db)+'\nAS '+Table.to_str(self, db)
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2336
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aaronmk
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if self.cols != None: str_ += ' ('+(', '.join(self.cols))+')'
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return str_
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def to_Table(self): return Table(self.name)
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2335
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aaronmk
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##### Columns
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2211
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aaronmk
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class Col(Code):
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def __init__(self, name, table=None):
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'''
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@param table Table|None (for no table)
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'''
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2241
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aaronmk
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if util.is_str(table): table = Table(table)
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2211
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aaronmk
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assert table == None or isinstance(table, Table)
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self.name = name
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self.table = table
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def to_str(self, db):
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str_ = ''
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if self.table != None: str_ += self.table.to_str(db)+'.'
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2348
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aaronmk
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str_ += db.esc_name(self.name)
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2211
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aaronmk
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return str_
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2314
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aaronmk
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def to_Col(self): return self
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2211
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aaronmk
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2393
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aaronmk
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def is_table_col(col): return col.table != None
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2260
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aaronmk
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def as_Col(col, table=None):
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2333
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aaronmk
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assert col != None
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if isinstance(col, Code): return col
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2260
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aaronmk
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else: return Col(col, table)
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2401
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aaronmk
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def to_name_only_col(col, check_table=None):
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col = as_Col(col)
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if check_table != None:
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table = col.table
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assert table == None or table == check_table
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return Col(col.name)
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2323
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aaronmk
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class NamedCol(Col):
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2229
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aaronmk
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def __init__(self, name, code):
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2310
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aaronmk
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Col.__init__(self, name)
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2229
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aaronmk
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if not isinstance(code, Code): code = Literal(code)
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self.code = code
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def to_str(self, db):
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2310
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aaronmk
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return self.code.to_str(db)+' AS '+Col.to_str(self, db)
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2314
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aaronmk
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def to_Col(self): return Col(self.name)
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2229
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aaronmk
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2462
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aaronmk
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def remove_col_rename(col):
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if isinstance(col, NamedCol): col = col.code
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return col
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2524
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aaronmk
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##### Functions
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class Function(Table): pass
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class FunctionCall(Code):
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def __init__(self, function, *args):
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'''
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@param args [Code...] The function's arguments
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'''
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if not isinstance(function, Code): function = Function(function)
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self.function = function
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self.args = args
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def to_str(self, db):
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args_str = ', '.join((v.to_str(db) for v in self.args))
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return self.function.to_str(db)+'('+args_str+')'
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def __repr__(self): return self.to_str(mockDb, '<args>')
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2335
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aaronmk
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##### Conditions
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2259
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aaronmk
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2398
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aaronmk
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class ColValueCond(Code):
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def __init__(self, col, value):
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value = as_ValueCond(value)
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self.col = col
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self.value = value
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def to_str(self, db): return self.value.to_str(db, self.col)
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##### Condition column comparisons
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2514
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aaronmk
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class ValueCond(BasicObject):
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2213
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aaronmk
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def __init__(self, value):
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| 180 |
2225
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aaronmk
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if not isinstance(value, Code): value = Literal(value)
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| 181 |
2462
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aaronmk
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value = remove_col_rename(value)
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| 182 |
2213
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aaronmk
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self.value = value
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| 184 |
2214
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aaronmk
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| 185 |
2216
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aaronmk
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def to_str(self, db, left_value):
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| 186 |
2214
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aaronmk
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'''
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| 187 |
2216
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aaronmk
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@param left_value The Code object that the condition is being applied on
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| 188 |
2214
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aaronmk
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'''
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| 189 |
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raise NotImplemented()
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| 190 |
2228
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aaronmk
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| 191 |
2514
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aaronmk
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def __repr__(self): return self.to_str(mockDb, '<left_value>')
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| 192 |
2211
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aaronmk
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| 193 |
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class CompareCond(ValueCond):
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def __init__(self, value, operator='='):
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| 195 |
2222
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aaronmk
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'''
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| 196 |
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@param operator By default, compares NULL values literally. Use '~=' or
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'~!=' to pass NULLs through.
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'''
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| 199 |
2211
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aaronmk
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ValueCond.__init__(self, value)
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self.operator = operator
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| 202 |
2216
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aaronmk
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def to_str(self, db, left_value):
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| 203 |
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if not isinstance(left_value, Code): left_value = Col(left_value)
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| 204 |
2462
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aaronmk
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left_value = remove_col_rename(left_value)
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| 205 |
2216
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aaronmk
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| 206 |
2222
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aaronmk
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right_value = self.value
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left = left_value.to_str(db)
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right = right_value.to_str(db)
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| 210 |
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# Parse operator
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| 211 |
2216
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aaronmk
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operator = self.operator
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| 212 |
2222
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aaronmk
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passthru_null_ref = [False]
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| 213 |
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operator = strings.remove_prefix('~', operator, passthru_null_ref)
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| 214 |
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neg_ref = [False]
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operator = strings.remove_prefix('!', operator, neg_ref)
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equals = operator.endswith('=')
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if equals and is_null(self.value): operator = 'IS'
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| 218 |
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# Create str
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str_ = left+' '+operator+' '+right
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| 221 |
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if equals and not passthru_null_ref[0] and isinstance(right_value, Col):
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| 222 |
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str_ += ' OR ('+left+' IS NULL AND '+right+' IS NULL)'
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| 223 |
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if neg_ref[0]: str_ = 'NOT ('+str_+')'
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| 224 |
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return str_
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| 225 |
2216
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aaronmk
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| 226 |
2260
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aaronmk
|
# Tells as_ValueCond() to assume a non-ValueCond is a literal value
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| 227 |
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assume_literal = object()
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| 228 |
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| 229 |
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def as_ValueCond(value, default_table=assume_literal):
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| 230 |
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if not isinstance(value, ValueCond):
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| 231 |
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if default_table is not assume_literal:
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| 232 |
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value = as_Col(value, default_table)
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| 233 |
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return CompareCond(value)
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| 234 |
2216
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aaronmk
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else: return value
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| 235 |
2219
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aaronmk
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| 236 |
2335
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aaronmk
|
##### Joins
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| 237 |
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| 238 |
2352
|
aaronmk
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join_same = object() # tells Join the left and right columns have the same name
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| 239 |
2260
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aaronmk
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| 240 |
2353
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aaronmk
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# Tells Join the left and right columns have the same name and are never NULL
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| 241 |
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join_same_not_null = object()
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| 242 |
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| 243 |
2260
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aaronmk
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filter_out = object() # tells Join to filter out rows that match the join
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| 244 |
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| 245 |
2514
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aaronmk
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class Join(BasicObject):
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| 246 |
2260
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aaronmk
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def __init__(self, table, mapping, type_=None):
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| 247 |
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'''
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| 248 |
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@param mapping dict(right_table_col=left_table_col, ...)
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| 249 |
2352
|
aaronmk
|
* if left_table_col is join_same: left_table_col = right_table_col
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| 250 |
2353
|
aaronmk
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* Note that right_table_col must be a string
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| 251 |
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* if left_table_col is join_same_not_null:
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| 252 |
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left_table_col = right_table_col and both have NOT NULL constraint
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| 253 |
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* Note that right_table_col must be a string
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| 254 |
2260
|
aaronmk
|
@param type_ None (for plain join)|str (e.g. 'LEFT')|filter_out
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| 255 |
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* filter_out: equivalent to 'LEFT' with the query filtered by
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| 256 |
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`table_pkey IS NULL` (indicating no match)
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| 257 |
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'''
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| 258 |
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if util.is_str(table): table = Table(table)
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| 259 |
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assert type_ == None or util.is_str(type_) or type_ is filter_out
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| 260 |
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| 261 |
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self.table = table
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| 262 |
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self.mapping = mapping
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| 263 |
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self.type_ = type_
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| 264 |
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| 265 |
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def to_str(self, db, left_table):
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| 266 |
2353
|
aaronmk
|
# Switch order (left_table is on the right in the comparison)
|
| 267 |
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right_table = left_table
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| 268 |
|
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left_table = self.table # note left_table is reassigned
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| 269 |
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| 270 |
2260
|
aaronmk
|
def join(entry):
|
| 271 |
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'''Parses non-USING joins'''
|
| 272 |
|
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right_table_col, left_table_col = entry
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| 273 |
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| 274 |
2353
|
aaronmk
|
# Switch order (right_table_col is on the left in the comparison)
|
| 275 |
|
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left = right_table_col
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| 276 |
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right = left_table_col
|
| 277 |
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|
| 278 |
2260
|
aaronmk
|
# Parse special values
|
| 279 |
2353
|
aaronmk
|
if right is join_same: right = left
|
| 280 |
|
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elif right is join_same_not_null:
|
| 281 |
|
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right = CompareCond(as_Col(left, right_table), '~=')
|
| 282 |
2260
|
aaronmk
|
|
| 283 |
2353
|
aaronmk
|
right = as_ValueCond(right, right_table)
|
| 284 |
2410
|
aaronmk
|
return '('+right.to_str(db, as_Col(left, left_table))+')'
|
| 285 |
2260
|
aaronmk
|
|
| 286 |
2265
|
aaronmk
|
# Create join condition
|
| 287 |
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type_ = self.type_
|
| 288 |
2276
|
aaronmk
|
joins = self.mapping
|
| 289 |
2265
|
aaronmk
|
if type_ is not filter_out and reduce(operator.and_,
|
| 290 |
2460
|
aaronmk
|
(v is join_same_not_null for v in joins.itervalues())):
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| 291 |
2260
|
aaronmk
|
# all cols w/ USING, so can use simpler USING syntax
|
| 292 |
2298
|
aaronmk
|
cols = (as_Col(v).to_str(db) for v in joins.iterkeys())
|
| 293 |
|
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join_cond = 'USING ('+(', '.join(cols))+')'
|
| 294 |
2467
|
aaronmk
|
else: join_cond = 'ON\n'+('\nAND\n'.join(map(join, joins.iteritems())))
|
| 295 |
2260
|
aaronmk
|
|
| 296 |
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# Create join
|
| 297 |
|
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if type_ is filter_out: type_ = 'LEFT'
|
| 298 |
2266
|
aaronmk
|
str_ = ''
|
| 299 |
|
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if type_ != None: str_ += type_+' '
|
| 300 |
2353
|
aaronmk
|
str_ += 'JOIN '+left_table.to_str(db)+' '+join_cond
|
| 301 |
2266
|
aaronmk
|
return str_
|
| 302 |
2349
|
aaronmk
|
|
| 303 |
2514
|
aaronmk
|
def __repr__(self): return self.to_str(mockDb, '<left_table>')
|
| 304 |
2424
|
aaronmk
|
|
| 305 |
|
|
##### Value exprs
|
| 306 |
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| 307 |
|
|
row_count = CustomCode('count(*)')
|
