sqlite

问题 This is a simple question. Background I'm supposed to have max of 400 rows in some table, based on timestamp field, so old ones will be removed automatically. For here, let's say it's 3 instead. The table has various fields, but the timestamp is what's important here. The problem Even though I've succeeded (looked here), for some reason it got me to a max of an additional item, so I just adjusted it accordingly. This means that instead of 3, I got 4 items. private const val MAX_ITEMS = 3

问题 I'm trying to concatenate many querysets together. I tried out the marked answer from this question a while back, but that didn't work in my case. I needed to return a queryset not a list. So I used the | , from the second answer. This worked fine at the time, but now that I'm trying to use it again for something else I get the following error: Expression tree is too large (maximum depth 1000) I originally thought that | would concat the querysets, but after reading the docs it appears that

问题 I'm trying to concatenate many querysets together. I tried out the marked answer from this question a while back, but that didn't work in my case. I needed to return a queryset not a list. So I used the | , from the second answer. This worked fine at the time, but now that I'm trying to use it again for something else I get the following error: Expression tree is too large (maximum depth 1000) I originally thought that | would concat the querysets, but after reading the docs it appears that

问题 I'm trying to concatenate many querysets together. I tried out the marked answer from this question a while back, but that didn't work in my case. I needed to return a queryset not a list. So I used the | , from the second answer. This worked fine at the time, but now that I'm trying to use it again for something else I get the following error: Expression tree is too large (maximum depth 1000) I originally thought that | would concat the querysets, but after reading the docs it appears that

问题 I have these codes below: many_posts = BlogPost.query.filter(or_((BlogPost.problem_name.ilike("%" + form.search.data + "%")),(BlogPost.text.ilike("%" + form.search.data + "%")))).order_by(BlogPost.date.desc()).paginate(page=page, per_page=10) return render_template('blog_search_result.html', id_list=id_list, many_posts=many_posts, no_posts=no_posts) It's an sqlalchemy query command and it let users on my website to search/filter and query blogs. But sometimes, the input they give is not in

问题 I am not sure what title has to be here to correctly reflect my question, I can only describe what I want. There is a table with fields: id, name, city There are next rows: 1 John London 2 Mary Paris 3 John Paris 4 Samy London I want to get a such result: London Paris Total 2 2 John 1 1 Mary 0 1 Samy 1 0 So, I need to take all unique values of name and find an appropriate quantity for unique values of another field (city) Also I want to get a total quantity of each city Simple way to do it is

问题 I am not sure what title has to be here to correctly reflect my question, I can only describe what I want. There is a table with fields: id, name, city There are next rows: 1 John London 2 Mary Paris 3 John Paris 4 Samy London I want to get a such result: London Paris Total 2 2 John 1 1 Mary 0 1 Samy 1 0 So, I need to take all unique values of name and find an appropriate quantity for unique values of another field (city) Also I want to get a total quantity of each city Simple way to do it is

问题 I am not sure what title has to be here to correctly reflect my question, I can only describe what I want. There is a table with fields: id, name, city There are next rows: 1 John London 2 Mary Paris 3 John Paris 4 Samy London I want to get a such result: London Paris Total 2 2 John 1 1 Mary 0 1 Samy 1 0 So, I need to take all unique values of name and find an appropriate quantity for unique values of another field (city) Also I want to get a total quantity of each city Simple way to do it is

问题 I'm trying to find out how to do something like the answer to this question but using SQLAlchemy. Having a hard time finding how to order query results by the difference between two columns without resorting to raw SQL. Any help is greatly appreciated!! Also, just out of curiosity, is it possible to create a column that automatically calculates the difference between two other columns? For example, you would have a revenue and loss column, and then a profit column that automatically combined

问题 Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed last month . Is there a built-in way in SQLite (or similar) to keep the best of both worlds SQL / NoSQL, for small projects, i.e.: stored in a (flat) file like SQLite (no client/server scheme, no server to install; more precisely : nothing else to install except pip install <package> ) possibility