[Sqlalchemy-tickets] Issue #3122: TypeError: unbound method _compiler_dispatch() must be called with Text instance as first argument (zzzeek/sqlalchemy)

[Martijn v. O. <iss...@bi...>]

New issue 3122: TypeError: unbound method _compiler_dispatch() must be called with Text instance as first argument
https://bitbucket.org/zzzeek/sqlalchemy/issue/3122/typeerror-unbound-method

Martijn van Oosterhout:

There appears to be a problem using with_variant with sqlite. Consider this example program:

    import sqlalchemy
    from sqlalchemy import Text, Column, create_engine
    from sqlalchemy.ext.declarative import declarative_base
    
    #MyType = Text().with_variant(Text, 'postgresql')   # works
    MyType = Text().with_variant(Text, 'sqlite')    # breaks
    
    Base = declarative_base()
    
    Base.metadata.bind = create_engine('sqlite://')
    
    class TestTable(Base):
        __tablename__ = 'test'
        column = Column('test', MyType, primary_key=True)
    
    print sqlalchemy.__version__
    Base.metadata.create_all()

Dies for me with the following error on 0.8.4 and 0.9.6:

    Traceback (most recent call last):
      File "test2.py", line 17, in <module>
        Base.metadata.create_all()
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/schema.py", line 2848, in create_all
        tables=tables)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1479, in _run_visitor
        conn._run_visitor(visitorcallable, element, **kwargs)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1122, in _run_visitor
        **kwargs).traverse_single(element)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/sql/visitors.py", line 122, in traverse_single
        return meth(obj, **kw)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/ddl.py", line 70, in visit_metadata
        self.traverse_single(table, create_ok=True)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/sql/visitors.py", line 122, in traverse_single
        return meth(obj, **kw)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/ddl.py", line 89, in visit_table
        self.connection.execute(schema.CreateTable(table))
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 662, in execute
        params)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 714, in _execute_ddl
        compiled = ddl.compile(dialect=dialect)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/sql/expression.py", line 1920, in compile
        return self._compiler(dialect, bind=bind, **kw)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/schema.py", line 2954, in _compiler
        return dialect.ddl_compiler(dialect, self, **kw)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/interfaces.py", line 804, in __init__
        self.string = self.process(self.statement, **compile_kwargs)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/interfaces.py", line 823, in process
        return obj._compiler_dispatch(self, **kwargs)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/sql/visitors.py", line 80, in _compiler_dispatch
        return meth(self, **kw)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/sql/compiler.py", line 1941, in visit_create_table
        and not first_pk)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/interfaces.py", line 823, in process
        return obj._compiler_dispatch(self, **kwargs)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/sql/visitors.py", line 80, in _compiler_dispatch
        return meth(self, **kw)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/sql/compiler.py", line 1980, in visit_create_column
        first_pk=first_pk
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/dialects/sqlite/base.py", line 484, in get_column_specification
        coltype = self.dialect.type_compiler.process(column.type)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/interfaces.py", line 869, in process
        return type_._compiler_dispatch(self)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/sql/visitors.py", line 80, in _compiler_dispatch
        return meth(self, **kw)
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/sql/compiler.py", line 2366, in visit_type_decorator
        return self.process(type_.type_engine(self.dialect))
      File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/interfaces.py", line 869, in process
        return type_._compiler_dispatch(self)
    TypeError: unbound method _compiler_dispatch() must be called with Text instance as first argument (got SQLiteTypeCompiler instance instead)

If you use the line involving 'postgresql' instead, it works just fine.