Timeline for Are (basic) SQL queries semantically equivalent to Higher Order Functions?
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 10, 2015 at 21:01 | vote | accept | Sridhar Sarnobat | ||
| Jun 10, 2015 at 19:57 | comment | added | Ixrec | To be fair, the OP did phrase the question as "are SQL queries equivalent to higher-order functions", not "is the SQL language equivalent to a functional programming language", so neither answer is wrong. | |
| Jun 10, 2015 at 18:57 | vote | accept | Sridhar Sarnobat | ||
| Jun 10, 2015 at 18:57 | |||||
| Jun 10, 2015 at 18:54 | comment | added | Sridhar Sarnobat | Maybe I didn't phrase the question formally enough. I guess I don't need it to be bidirectionally equivalent in 100% of cases. Just that the typical queries through one approach can be rewritten as another. | |
| Jun 10, 2015 at 18:52 | comment | added | Sridhar Sarnobat | I like this answer for different reasons to the other answer that talks about relational algebra. Ideally I'd mark both as correct. | |
| Jun 10, 2015 at 18:23 | comment | added | Bart van Ingen Schenau | For a semantic equivalence, I would expect that you can show it in both directions. Both that SQL queries can be expressed in higher-order functions and that you can express a higher-order function in SQL syntax. | |
| Jun 10, 2015 at 18:17 | comment | added | Mason Wheeler | @Bart: Then question was "is there a sound semantic equivalence that can be proven?" Implementing one thing in terms of another is a time-honored technique for proving equivalence in computer science. For example, one way to prove that a language is Turing-complete by using it to implement another language that is already known to be Turing-complete. | |
| Jun 10, 2015 at 18:16 | comment | added | Bart van Ingen Schenau | This only demonstrates that higher-order functions can be used to realize SQL operations, not that the two are related to each other in general. | |
| Jun 10, 2015 at 18:10 | history | answered | Mason Wheeler | CC BY-SA 3.0 |