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# SQL code generation
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3
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import sql
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4
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5
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class Code:
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6
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def to_str(self, db): raise NotImplemented()
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7
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8
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class Literal:
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def __init__(self, value): self.value = value
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10
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def to_str(self, db): return db.esc_value(self.value)
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class Table(Code):
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def __init__(self, name, schema=None):
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15
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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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def to_str(self, db): return sql.qual_name(db, self.schema, self.name)
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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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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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str_ += sql.esc_name(db, self.name)
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return str_
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class ValueCond:
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def __init__(self, value):
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if not isinstance(value, Literal): value = Literal(value)
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self.value = value
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def to_str(self, db, value_code):
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'''
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@param value_code The SQL code that the condition is being applied on
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'''
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raise NotImplemented()
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50
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class CompareCond(ValueCond):
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52
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def __init__(self, value, operator='='):
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ValueCond.__init__(self, value)
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self.operator = operator
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56
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def to_str(self, db, value_code):
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return value_code+' '+self.operator+' '+self.value.to_str(db)
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