Suppose you have a table "foo"
in postgres with column name "col (parens) name"
. The psql command
INSERT INTO "foo" ("col (parens) name") VALUES ('bar');
works just fine. However, if I try to do the same using sqlalchemy (version 0.9.7), the resulting python code fails:
conn = sqlalchemy.create_engine('postgresql://name:password@host:port/database')
meta = sqlalchemy.schema.MetaData()
meta.reflect(bind=conn)
foo = meta.tables['foo']
vals = [{'col (parens) name': 'hi'}, {'col (parens) name': 'bye'}]
conn.execute(foo.insert(values=vals))
This does not work, giving the following error:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "sqlalchemy/engine/base.py", line 729, in execute
return meth(self, multiparams, params)
File "sqlalchemy/sql/elements.py", line 321, in _execute_on_connection
return connection._execute_clauseelement(self, multiparams, params)
File "sqlalchemy/engine/base.py", line 826, in _execute_clauseelement
compiled_sql, distilled_params
File "sqlalchemy/engine/base.py", line 957, in _execute_context
context)
File "sqlalchemy/engine/base.py", line 1162, in _handle_dbapi_exception
util.reraise(*exc_info)
File "sqlalchemy/engine/base.py", line 950, in _execute_context
context)
File "sqlalchemy/engine/default.py", line 436, in do_execute
cursor.execute(statement, parameters)
KeyError: 'col (parens'
Apparently the sqlalchemy method to bind db parameters is running into trouble with python string interpolation. Any suggestions for a workaround?
Add paramstyle="format"
to the create_engine
call. It will change the way the query values are inserted to the query in a way that it won't crash on closing brackets.
conn = sqlalchemy.create_engine(
'postgresql://name:password@host:port/database',
paramstyle="format"
)
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