5 ms·

This is an odd take. Your programming language works with objects, the data is in relational tables, you need software to map the relations to objects. Thus the

This is an odd take. Your programming language works with objects, the data is in relational tables, you need software to map the relations to objects. Thus the Object Relational Mapper. There's no reason you can't write SQL and let an ORM handle the result set mapping.

sgarland 2y ago
If that’s all you were doing, then maybe, but it never is. ORMs enable people who have no idea how RDBMS works to use them, which rarely ends well. I’m not suggesting that to use RDBMS you should know how to administrate and tune it (though it helps), but knowing their language, and understanding a single data structure (B+ trees) isn’t too much to ask, I think.
- gedy 2y ago
  > ORMs enable people who have no idea how RDBMS works to use them, which rarely ends well. In some cases, but the more frequent issue I saw back in the day was the DBA making some really complex schema tuned for what they wanted, then an application trying to use the data in a pretty reasonable OOP manner (1 to many relationships, etc) and the DBA pissed they were using an ORM instead of their perfect SQL queries and procedures.
  - sgarland 2y ago
    > the DBA pissed they were using an ORM instead of their perfect SQL queries and procedures. Tbh, I don't understand why this is seen as a bad thing. Correction: I know why it is (any changes are obviously going to be dramatically slowed down), but in the long run, I don't understand why people are against it. You wanted something done correctly, so you went to the SME for that specific field, and had them do it for you. Then you decided to throw it away?! Why are you bothering to ask them in the first place? > 1 to many relationships, etc I know this was just an example, but 1:M is a perfectly natural part of any RDBMS, and in no way requires an ORM to be done.
    - gedy 2y ago
      > Then you decided to throw it away?! Why are you bothering to ask them in the first place? Usually this was a mismatch of mgmt or expectations. Hiring old school DBAs and letting them think they "own the data", while plopping them into a huge dev team changing the big SaaS features daily is a recipe for trouble. I don't fault DBAs per se, though I did work with some who wouldn't look outside their blinders at all.
- stickfigure 2y ago
  Of course. And after you understand SQL and databases, ORMs can save you a lot of typing. I've never understood the either/or attitude.
  - sgarland 2y ago
    Sometimes it can. Other times, you have the SQL already written in your head, but then you have to figure out how to coerce the ORM to doing what you want.
    - stickfigure 2y ago
      Even Hibernate has `em.createNativeQuery("type your sql here", SomeResult.class)`. I've never seen an ORM (for an RDBMS) that didn't make it easy to run SQL.
      - crabbone 2y ago
        Then what's the point of using Hibernate? Just use the ODBM driver... why are you dragging the gorilla and all of the jungle with you if all you wanted was a banana?
        stickfigure 2y ago
        Since we're talking about Hibernate, I assume you mean the JDBC driver? Because the API is tedious and unpleasant. The mapping of database results to java objects with Hibernate is convenient. The basic "load entity, change a couple fields, let Hibernate persist it" flow is convenient. In a limited set of cases, basic entity graph navigation is convenient. As I said, if you're working in an object-based language, by definition you need something that maps relations to objects. Hibernate is a competent choice. There are other competent choices, but JDBC is not one of them unless your app is trivial.
        crabbone 2y ago
        Yeah, I confused multiple acronyms here :) Anyways. Hibernate works on top of JDBC, so, if you like its interface, then it means you could make your own, but skipping >99% of the rest of Hibernate code that has nothing to do with wrapping the driver. Or, imagine there was a library Hibernate', that threw away all the ORM stuff, and only offered mapping of SQL results to Java objects and sending queries to the database. Then, why not use Hibernate' instead of Hibernate? NB. About triviality. From experience: trivial apps tend to work OK with ORM. Non-trivial will usually ditch the ORM because of performance, missing functionality and general difficulty with servicing it. So, it's the other way around: if you are shooting for the stars, you are probably not going to use Hibernate, Hibernate is one of the variety of tools that helps losers loose less, it's not a tool for the winners.
crabbone 2y ago
Nah. That's an inconsequential part of the interaction between the database and the application. The reality is that your code has both, the database and the application. And if you want to write good software, you need to know how both work and be an expert at that. It's infinitely easier and less error-prone to keep the interface between the database and the application to the minimum (just convert the final results of a query to the application objects and embed complete queries in the application code) than to try and create complex query builders behind the scenes of object-to-object interaction. If you want to make a good product, you may start with ORM, as it may, for a time, delay the need of understanding the relationship between the application and the database, and allow you to experiment faster at the expense of lost performance. Once you know what you need to do, ORM just no longer works: you will have to break it at least in order to deal with performance issues, but often you will also find yourself dealing with the fact that a lot of what you want to express in your queries is either too difficult or even impossible to express in a particular ORM.
reaanb2 2y ago
> you need software to map the relations to objects If you start with a network data model perspective and build that into your system, then it follows that you'll want a network data model to SQL mapper. That's what ORMs are, and the need for them comes from your approach, not from the tools you use. There's a different approach - use OOP to build computational abstractions rather than model data. Use it to decompose the solution rather than model the problem. Have objects that talk to the database, exchange sets of facts between it and themselves, and process sets of facts. In the process, you can also start viewing data relationally - as n-ary relations over sets of values - as opposed to binary relationships between tables of records. Information systems are not domain simulations, simulations compute the future state of the domain whereas information systems derive facts from known facts at the present time. For a visual metaphor, car engineers don't use roadmaps as design diagrams and they don't model the problem domain in the systems they build. A car isn't built from streets, turns, road signs, traffic lights, etc. And despite that, cars function perfectly well in the problem domain. A car generally doesn't need to be refactored and reassembled when roads or rules change.

sgarland 2y ago

If that’s all you were doing, then maybe, but it never is. ORMs enable people who have no idea how RDBMS works to use them, which rarely ends well. I’m not suggesting that to use RDBMS you should know how to administrate and tune it (though it helps), but knowing their language, and understanding a single data structure (B+ trees) isn’t too much to ask, I think.

gedy 2y ago
> ORMs enable people who have no idea how RDBMS works to use them, which rarely ends well. In some cases, but the more frequent issue I saw back in the day was the DBA making some really complex schema tuned for what they wanted, then an application trying to use the data in a pretty reasonable OOP manner (1 to many relationships, etc) and the DBA pissed they were using an ORM instead of their perfect SQL queries and procedures.
- sgarland 2y ago
  > the DBA pissed they were using an ORM instead of their perfect SQL queries and procedures. Tbh, I don't understand why this is seen as a bad thing. Correction: I know why it is (any changes are obviously going to be dramatically slowed down), but in the long run, I don't understand why people are against it. You wanted something done correctly, so you went to the SME for that specific field, and had them do it for you. Then you decided to throw it away?! Why are you bothering to ask them in the first place? > 1 to many relationships, etc I know this was just an example, but 1:M is a perfectly natural part of any RDBMS, and in no way requires an ORM to be done.
  - gedy 2y ago
    > Then you decided to throw it away?! Why are you bothering to ask them in the first place? Usually this was a mismatch of mgmt or expectations. Hiring old school DBAs and letting them think they "own the data", while plopping them into a huge dev team changing the big SaaS features daily is a recipe for trouble. I don't fault DBAs per se, though I did work with some who wouldn't look outside their blinders at all.
stickfigure 2y ago
Of course. And after you understand SQL and databases, ORMs can save you a lot of typing. I've never understood the either/or attitude.
- sgarland 2y ago
  Sometimes it can. Other times, you have the SQL already written in your head, but then you have to figure out how to coerce the ORM to doing what you want.
  - stickfigure 2y ago
    Even Hibernate has `em.createNativeQuery("type your sql here", SomeResult.class)`. I've never seen an ORM (for an RDBMS) that didn't make it easy to run SQL.
    - crabbone 2y ago
      Then what's the point of using Hibernate? Just use the ODBM driver... why are you dragging the gorilla and all of the jungle with you if all you wanted was a banana?
      - stickfigure 2y ago
        Since we're talking about Hibernate, I assume you mean the JDBC driver? Because the API is tedious and unpleasant. The mapping of database results to java objects with Hibernate is convenient. The basic "load entity, change a couple fields, let Hibernate persist it" flow is convenient. In a limited set of cases, basic entity graph navigation is convenient. As I said, if you're working in an object-based language, by definition you need something that maps relations to objects. Hibernate is a competent choice. There are other competent choices, but JDBC is not one of them unless your app is trivial.
        crabbone 2y ago
        Yeah, I confused multiple acronyms here :) Anyways. Hibernate works on top of JDBC, so, if you like its interface, then it means you could make your own, but skipping >99% of the rest of Hibernate code that has nothing to do with wrapping the driver. Or, imagine there was a library Hibernate', that threw away all the ORM stuff, and only offered mapping of SQL results to Java objects and sending queries to the database. Then, why not use Hibernate' instead of Hibernate? NB. About triviality. From experience: trivial apps tend to work OK with ORM. Non-trivial will usually ditch the ORM because of performance, missing functionality and general difficulty with servicing it. So, it's the other way around: if you are shooting for the stars, you are probably not going to use Hibernate, Hibernate is one of the variety of tools that helps losers loose less, it's not a tool for the winners.

crabbone 2y ago

Nah. That's an inconsequential part of the interaction between the database and the application. The reality is that your code has both, the database and the application. And if you want to write good software, you need to know how both work and be an expert at that. It's infinitely easier and less error-prone to keep the interface between the database and the application to the minimum (just convert the final results of a query to the application objects and embed complete queries in the application code) than to try and create complex query builders behind the scenes of object-to-object interaction. If you want to make a good product, you may start with ORM, as it may, for a time, delay the need of understanding the relationship between the application and the database, and allow you to experiment faster at the expense of lost performance. Once you know what you need to do, ORM just no longer works: you will have to break it at least in order to deal with performance issues, but often you will also find yourself dealing with the fact that a lot of what you want to express in your queries is either too difficult or even impossible to express in a particular ORM.

reaanb2 2y ago

> you need software to map the relations to objects If you start with a network data model perspective and build that into your system, then it follows that you'll want a network data model to SQL mapper. That's what ORMs are, and the need for them comes from your approach, not from the tools you use. There's a different approach - use OOP to build computational abstractions rather than model data. Use it to decompose the solution rather than model the problem. Have objects that talk to the database, exchange sets of facts between it and themselves, and process sets of facts. In the process, you can also start viewing data relationally - as n-ary relations over sets of values - as opposed to binary relationships between tables of records. Information systems are not domain simulations, simulations compute the future state of the domain whereas information systems derive facts from known facts at the present time. For a visual metaphor, car engineers don't use roadmaps as design diagrams and they don't model the problem domain in the systems they build. A car isn't built from streets, turns, road signs, traffic lights, etc. And despite that, cars function perfectly well in the problem domain. A car generally doesn't need to be refactored and reassembled when roads or rules change.