I am trying out sqlalchemy and i am using this connection string to connect to my databases Does sqlalchemy create an sqlite database for you if one is not already present in a directory it was supposed to fetch the database file?. Answer Yes,sqlalchemy does create a database for you.I confirmed it on windows using this code
Tag: sqlalchemy
How to count rows with SELECT COUNT(*) with SQLAlchemy?
I’d like to know if it’s possible to generate a SELECT COUNT(*) FROM TABLE statement in SQLAlchemy without explicitly asking for it with execute(). If I use: session.query(table).count() then it …
SQLalchemy specify which index to use
Is there a way in SQLalchemy to tell the query which index to use? The reason I need this is that the SQL queries it generates use the “wrong” index – there exists an index for exactly the two fields that I have and it doesn’t use it. Thanks! Answer I think you can use with_hint() for this. e.g. Honestly,
sqlalchemy simple example of `sum`, `average`, `min`, `max`
For sqlalchemy, Who can gently give simple examples of SQL functions like sum, average, min, max, for a column (score in the following as an example). As for this mapper: Answer See SQL Expression Language Tutorial for the usage. The code below shows the usage:
RIGHT OUTER JOIN in SQLAlchemy
I have two tables beard and moustache defined below: I have created a SQL Query in PostgreSQL which will combine these two tables and generate following result: Query: However I can not create SQLAlchemy representation of it. I tried several ways from implementing from_statement to outerjoin but none of them really worked. Can anyone help me with it? Answer From
creating a temporary table from a query using sqlalchemy orm
I can create a temporary table this way: but the new table is unreadable because it says it has no primary key. existingtable.id is the primary key of exisitingtable, so I expected it to get the same treatment in the temp table. However, I would rather find some ORM way of doing this anyway. Given: How can I populate temp_table
How to query database by id using SqlAlchemy?
I need to query a SQLAlchemy database by its id something similar to but for id. How do I do this? [Searching over Google and SO didn’t help] Answer Query has a get function that supports querying by the primary key of the table, which I assume that id is. For example, to query for an object with ID of
Select NULL Values in SQLAlchemy
Here’s my (PostgreSQL) table — I want to select all people that are not known to be married, i.e., including those with NULL marriage_status. This does not work — Of course this does — The problem is that I’m accessing it from SQLAlchemy with — which gets translated to — And does not work — neither does — How should
Sqlalchemy complex in_ clause with tuple in list of tuples
I’m trying to find a way to cause SQLAlchemy to generate a query of the following form: select * from t where (a,b) in ((a1,b1),(a2,b2)); Is this possible? If not, any suggestions on a way to …