Jailer: A truly relational database client

by wisser • 5 years ago

85 17 5 years ago

civilized• 5 years ago

I would love to understand what this is for, but the README went over my head. The subsetting and such that this software does is definitely very consistent, topological and hierarchically structured, I've determined that much. It's got referential integrity too!

SomeCallMeTim• 5 years ago

Roughly: Say you have a relational database with a dozen tables that all connect to each other using foreign keys: A user table has a user id, a message table refers to a user, a log table refers to the user and a message, a comment table refers to a message and a user, and so forth.

Jailer can, say, grab a few comments from the comment table and at the same time grab any users and messages that were referenced. Then all of those records spread across all of the tables can be exported for use by, for instance, tests.

Imagine you found a bug, say, in your app logic, and you wanted to grab an image of the exact data that triggers the bug to repro that bug and use it in a test. This tool makes that easy.

rejectedandsad2• 5 years ago

Imagine you found a bug, say, in your app logic, and you wanted to grab an image of the exact data that triggers the bug to repro that bug and use it in a test. This tool makes that easy.

This is actually a fairly common usecase in my $DAYJOB, what's the typical name for a tool that does this (that isn't the above, since I don't use a SQLdb?)

politician• 5 years ago

Suppose you want to look at a couple of rows from a particular table in your database.

This tool will make those rows available locally along with all of the rows from all of the tables that might have a dependency on those initial rows, so that you can explore the entire space.

Equivalently, it's doing for your data what a package manager does for dependency management.

Equivalently, it's building a subgraph from a set of root nodes in the graph that is your database.

anigbrowl• 5 years ago

I dislike working with RDBs but this seems like will take a lot of the pain out of it.

tompazourek• 5 years ago

The "relations" in relational databases actually correspond to tables, not relationships between tables. Which makes the "truly relational" sound a bit silly...

See: https://en.wikipedia.org/wiki/Relation_(database)

helderoliozuzl2• 5 years ago

This is truly true.

foolmeonce2• 5 years ago

Has anyone seen anything similar but for browsers?

(I.e. I would like an extension popping CSV and other relational formats while surfing into the browser's DBs to then work with in a GUI like this.)

webmaven• 5 years ago

Something like CSV Reader?: https://chrome.google.com/webstore/detail/csv-reader/dnioinf...

foolmeonce2• 5 years ago

Not really, I want to scrape a relationship from the current page into a table to be used in joins, etc, with tables from other pages I have previously scraped. The current page being CSV is only an example of a clear relational table.

One can do similar things ~manually popping data into the domains Key-value DBs while scraping, then injecting a GUI to work with all the data, but a tool for doing this with relational database primitives would be more powerful as jailer demonstrates.

johannes12343212• 5 years ago

The data in one table would not be related to the data in the other tables. It would not be referentially intact.

The use of "related" in the docs and here in the title of the posting seems to make the typical wrong assumption, that "relational database" refers to the "relation" between "related" tables. However the theory refers to the relation between the tuples aka rows. Thus that the relation is the single table.

https://en.m.wikipedia.org/wiki/Relation_(database)

yyybcbcbc• 5 years ago

How would you phrase it correctly? After all, tables in a relational database are also related to each other.

johannes12343212• 5 years ago

You may "refer" to a different relation and have referential integrity between relations. Maybe "joinable" is also acceptable. You might also explicitly mention "foreign key" constraints.

Purely mathematically I believe. In relational algebra there is no term, as from a mathematical point you can join any relations. Whether that makes sense is a different question.

Jailer: A truly relational database client

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