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Tag: sqlite

Restrict “subcategory” based on other “category” column

I’m creating a SQLite database where I have 3 tables: transactions, categories, sub-categories in the transactions table, there is a column “category” with a foreign key to the categories table in the sub-categories table, there is column “parent-category” with a foreign key to the categories table Now, how can I ensure that the sub-category that I fill in with transactions

python function parameter control

I have a function called “getBooks”, and this function is actually a combination of 2 functions. one function must work without taking the ‘name’ parameter, the other must work by taking the ‘name’ parameter because i have to change the sql template according to the ‘name’ parameter. how can i provide that? Answer You can specify a default parameter of

Why does this suggested solution prefer a different way of calculating percentages based on aggregations?

I’m working through a problem set from CMU’s public db systems course. I have the following two tables: Order Id CustomerId EmployeeId OrderDate RequiredDate ShippedDate ShipVia Freight ShipName ShipAddress ShipCity ShipRegion ShipPostalCode ShipCountry 10248 VINET 5 2012-07-04 2012-08-01 2012-07-16 3 16.75 Vins et alcools Chevalier 59 rue de l’Abbaye Reims Western Europe 51100 France 10249 TOMSP 6 2012-07-05 2012-08-16 2012-07-10

How to optimize querying multiple unrelated tables in SQLite?

I have scenario when I have to iterate through multiple tables in quite big sqlite database. In tables I store informations about planet position on sky through years. So e.g. for Mars I have tables Mars_2000, Mars_2001 and so on. Table structure is always the same: Thing is that for certain task I need to iterate through this tables, which

Why does sqlite3 not escape metacharacters with parameterized values?

I’m making a database interface in python for a project where i need to encrypt everything that goes into my database and decrypt everything that goes out of it. Unfortunately some of my characters get encrypted to meta characters in sql and this gives trouble when selecting something from the database. The first thing that came up was to use

How to correctly compute cumulative distribution on sample dataset

Consider the following table and data set. I want to create a cumulative distribution that shows cumulative % of total Callers based on the values in the Callees column, for the group. For example, for the value Callees = 1, I would like the first output row: Where 0.6662 is 505 divided by total number of Callers, 758.Then the following