Describe the bug
Compiling a clause using literal_binds=True throws an error when the clause contains an "expanding" BindParameter on a type with a bind_expression() method.
I understand that this is a bug in an obscure corner of a feature whose use is discouraged in any case (for good reasons). It would be quite reasonable not to fix this, but I thought it was worth at least making a record of it in case others hit the same problem.
For our own use case we have been able to work around this by doing the parameter substitution ourselves, having run all the parameter values through literal_processor. In our particular context the usual considerations around untrusted inputs don't apply, so this is an acceptable solution.
To Reproduce
import sqlalchemy
class CustomType(sqlalchemy.types.TypeDecorator):
impl = sqlalchemy.types.String
def bind_expression(self, bindvalue):
return sqlalchemy.func.lower(bindvalue)
table = sqlalchemy.Table(
"t", sqlalchemy.MetaData(), sqlalchemy.Column("col", CustomType())
)
clause = table.c.col.in_(["ABC", "DEF"])
for compile_kwargs in [{"render_postcompile": True}, {"literal_binds": True}]:
print(f"{compile_kwargs=}")
print(clause.compile(compile_kwargs=compile_kwargs))
print()Error
compile_kwargs={'render_postcompile': True}
t.col IN (lower(:col_1_1), lower(:col_1_2))
compile_kwargs={'literal_binds': True}
Traceback (most recent call last):
File "/home/dave/projects/ebmdatalab/databuilder/reproduce_error_2.py", line 19, in <module>
print(clause.compile(compile_kwargs=compile_kwargs))
File "/home/dave/.virtualenvs/ebm-databuilder/lib/python3.9/site-packages/sqlalchemy/sql/elements.py", line 501, in compile
return self._compiler(dialect, **kw)
File "/home/dave/.virtualenvs/ebm-databuilder/lib/python3.9/site-packages/sqlalchemy/sql/elements.py", line 565, in _compiler
return dialect.statement_compiler(dialect, self, **kw)
File "/home/dave/.virtualenvs/ebm-databuilder/lib/python3.9/site-packages/sqlalchemy/sql/compiler.py", line 778, in __init__
Compiled.__init__(self, dialect, statement, **kwargs)
File "/home/dave/.virtualenvs/ebm-databuilder/lib/python3.9/site-packages/sqlalchemy/sql/compiler.py", line 451, in __init__
self.string = self.process(self.statement, **compile_kwargs)
File "/home/dave/.virtualenvs/ebm-databuilder/lib/python3.9/site-packages/sqlalchemy/sql/compiler.py", line 486, in process
return obj._compiler_dispatch(self, **kwargs)
File "/home/dave/.virtualenvs/ebm-databuilder/lib/python3.9/site-packages/sqlalchemy/sql/visitors.py", line 82, in _compiler_dispatch
return meth(self, **kw)
File "/home/dave/.virtualenvs/ebm-databuilder/lib/python3.9/site-packages/sqlalchemy/sql/compiler.py", line 2208, in visit_binary
return self._generate_generic_binary(
File "/home/dave/.virtualenvs/ebm-databuilder/lib/python3.9/site-packages/sqlalchemy/sql/compiler.py", line 2264, in _generate_generic_binary
+ binary.right._compiler_dispatch(
File "/home/dave/.virtualenvs/ebm-databuilder/lib/python3.9/site-packages/sqlalchemy/sql/visitors.py", line 82, in _compiler_dispatch
return meth(self, **kw)
File "/home/dave/.virtualenvs/ebm-databuilder/lib/python3.9/site-packages/sqlalchemy/sql/compiler.py", line 2427, in visit_bindparam
m.group(2),
AttributeError: 'NoneType' object has no attribute 'group'
Versions
- Python: 3.9
- SQLAlchemy: 1.4.39
Additional context
No response
Describe the bug
Compiling a clause using
literal_binds=Truethrows an error when the clause contains an "expanding"BindParameteron a type with abind_expression()method.I understand that this is a bug in an obscure corner of a feature whose use is discouraged in any case (for good reasons). It would be quite reasonable not to fix this, but I thought it was worth at least making a record of it in case others hit the same problem.
For our own use case we have been able to work around this by doing the parameter substitution ourselves, having run all the parameter values through
literal_processor. In our particular context the usual considerations around untrusted inputs don't apply, so this is an acceptable solution.To Reproduce
Error
Versions
Additional context
No response