ordbms

Referencing a row from another table (PostgreSQL)

大憨熊 提交于 2019-12-23 02:38:06
问题 I'm new to PostgreSQL and I'm struggling to understand how to use a reference to an 'instance' (or row) from a table as a value within a row of another table. Here is my desired result: class User{ int age; Post[] posts; } class Post{ int postId; ... } // Sql script sqlMain{ User k = new User(20); k.addPost(10, ...); } As you can see, I want an (dynamic prefereably, like an ArrayList) array of posts as an attribute of a user. So far I have the following Script: CREATE TABLE Post( postId INT )

What does PostgreSQL to be ORDBMS mean?

寵の児 提交于 2019-12-21 02:43:27
问题 Query has not much helped. As mentioned here, PostgreSQL is ORDBMS. here, it explains PostgreSQL being RDBMS. What does it mean that PostgreSQL is an ORDBMS? Is it about supporting user defined datatypes? 回答1: An ORDBMS is primarily a relational database that supports some object oriented features. PostgreSQL or Postgres ( not Post G res) supports table inheritance and function overloading. Both are features usually attributed to object oriented languages. One of the situations where the

Difference between RDBMS and ORDBMS

寵の児 提交于 2019-12-19 06:44:26
问题 It happened to me when I was reading about PostgreSQL on its wiki page where it refers to itself as an ORDBMS. I always knew about Microsoft SQL Server which is an RDBM system. Can someone help me understand the main differences between Relational Database Management System(RDBMS) and Object Relational Database Management System (ORDBMS) and in what scenarios should I use one of them? Also, my key question is related to the fact that in the world of Microsoft SQL Server we often use a layer

Difference between RDBMS and ORDBMS

馋奶兔 提交于 2019-12-19 06:43:14
问题 It happened to me when I was reading about PostgreSQL on its wiki page where it refers to itself as an ORDBMS. I always knew about Microsoft SQL Server which is an RDBM system. Can someone help me understand the main differences between Relational Database Management System(RDBMS) and Object Relational Database Management System (ORDBMS) and in what scenarios should I use one of them? Also, my key question is related to the fact that in the world of Microsoft SQL Server we often use a layer

Referencing a row from another table (PostgreSQL)

别等时光非礼了梦想. 提交于 2019-12-07 06:10:30
I'm new to PostgreSQL and I'm struggling to understand how to use a reference to an 'instance' (or row) from a table as a value within a row of another table. Here is my desired result: class User{ int age; Post[] posts; } class Post{ int postId; ... } // Sql script sqlMain{ User k = new User(20); k.addPost(10, ...); } As you can see, I want an (dynamic prefereably, like an ArrayList) array of posts as an attribute of a user. So far I have the following Script: CREATE TABLE Post( postId INT ) CREATE TABLE User( id INT, posts Post[] ) // Member function of User class CREATE FUNCTION addPost

What is the difference between an ORM and an ORDBMS?

倾然丶 夕夏残阳落幕 提交于 2019-12-02 04:44:52
问题 They seem very similar to me. I don't understand the difference Maybe a programming example for ORDBMS? 回答1: An ORM is just translation layer between objects from a programming language and relations in a relational database. It is not an RDBMS, nothing to manage a database here, just a translation / mapping layer. Read the tag info of orm. An ORDBMS is an RDBMS with object-oriented features. This one actually manages your database. I have written more at your preceding question. As mentioned

What is the difference between an ORM and an ORDBMS?

≡放荡痞女 提交于 2019-12-02 02:35:21
They seem very similar to me. I don't understand the difference Maybe a programming example for ORDBMS? Erwin Brandstetter An ORM is just translation layer between objects from a programming language and relations in a relational database. It is not an RDBMS, nothing to manage a database here, just a translation / mapping layer. Read the tag info of orm . An ORDBMS is an RDBMS with object-oriented features. This one actually manages your database. I have written more at your preceding question . As mentioned before, those two are very different in nature . 来源: https://stackoverflow.com