dialect has a has_table method:

engine.dialect.has_table(engine.connect(), "mytable")




On Apr 25, 2012, at 10:33 AM, Massi wrote:

> Thank you for your reply Wichert, I already used the Inspector method
> get_table_names(), but using that I'd have to check if a table name is
> present in a vector which can have 100.000 elements. This can be even
> slower if done for lots of times. Maybe I can perform a binary search,
> but I'm not sure that the resulting vector is ordered. Am I wrong?
> Other Ideas?
> 
> On 25 Apr, 16:11, Wichert Akkerman <[email protected]> wrote:
>> On 04/25/2012 03:57 PM, Massi wrote:
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>>> Hi everyone,
>> 
>>> in my script I have to deal with a huge database with thousands of
>>> tables. Given a table name (a python string) I would have to now if
>>> such a table exists or not. Up to now I have written this function:
>> 
>>> def DBGetTableByName(table_name) :
>>>          metadata = MetaData(engine)
>>>          try :
>>>              table = Table(table_name, metadata, autoload=True)
>>>              return table
>>>          except NoSuchTableError :
>>>              return None
>> 
>>> I use its return value to check if the table exists, but the problem
>>> is that it is too slow. Since I have to repeat this operation several
>>> times I wonder if there is a faster (and smarter) way to perform this
>>> control.
>>> Any hints?
>> 
>> Use the inspector:
>> 
>> from sqlalchemy.engine.reflection import Inspector
>> 
>> inspector = Inspector.from_engine(engine)
>> print table_name in inspector.get_table_names()
>> 
>> You can find the documentation 
>> here:http://docs.sqlalchemy.org/en/rel_0_7/core/schema.html?highlight=insp...
>> 
>> Wichert.
> 
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