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Overview

About

The ORM (Object-Relational-Mapping) allows you to access SQL databases without any need to write SQL query strings or map between SQL and java. Getting Started

Goals and State of the Project

The ORM attempts to make sensible decisions for developers while also granting the ability to overwrite these decisions. To illustrate this with an example:

The ORM ships with a DefaultMapper, which specifies, for instance, what Field in your model maps to which SQL datatype. You have the option to use your definition and partially use ours when it fits you already.

We consider our v1.0 goals achieved when the following features are implemented:

Type Definition: Elementary - If this feature is not included there will be SQL features which will become impossible to perform with the ORM.

Utility - If this feature is not included the developer will not be limited in options but needs to write more code to achive the same code

Decision - A utility feature, which forces some convention on the developer and should, thusly, be overwritable.

Relation Mapping

Achieved Tested Implemented Feature Type
Spec is WIP Info

Query Building

Achieved Tested Implemented Feature Type
No No No SELECT Clause (default: SELECT *) Elementary
Yes Yes Yes FROM Clause derived from Model Elementary
No No Yes WHERE Clause Elementary
No No Yes Nested WHERE Clause Elementary
No No Yes WHERE EXISTS Clause Elementary
No No No whereHas Utility
No No No has Utility
No No Yes ORDER BY Clause Elementary
No No No GROUP BY Clause Elementary
No No Yes OFFSET Clause Elementary
No No Yes LIMIT Clause Elementary
No No Yes HAVING Clause Elementary
No No Yes Belongs To (1:n) Relation Utility
No No Yes Has Many (n:1) Relation Utility
No No Yes Belongs To Many (n:n) Relation Utility
No No Only Count Aggregate Functions (only aggregate value returned) Elementary
No No No Aggregate Function (in conjunction with GROUP BY) Elementary
No No No Aggregate Function (with default value for null) Elementary

Automatic Migration

Achieved Tested Implemented Feature Type
No No Yes Default Size per config Utility
No No Yes Size configurable per column Essential
No No Yes Table name is the plural of class name Decision
No No Yes Table name configurable per model Essentials
No No Yes Column name is snake case of attribute name Decision
No No Yes Column name convention is overwritable to other cases Utility
No No Yes Column name is configurable per column Essential
No No No An index can be set per column Essential
No No Yes A primary key can be set per column Essential
No No No A primary key can be set across multiple columns Essential
No No Yes A unique attribute can be set per column Essential
No No No A foreign key can be set per column Essential
No No No ON DELETE Essential
No No No ON UPDATE Essential
No No No On Soft Delete Utility
No No Yes Auto-increment can be configured per column Essential
No No No Not nullable can be configured per column Essential

Processing

Achieved Tested Implemented Feature
No No Yes Timestamps (Created At, Updated At)
No No Yes Soft Deletes
No No Yes Observer

Security

Achieved Tested Implemented Feature
No No No SQL Injection Protection

Not included but considered features

Feature Type Reason
Raw Query Fragments Essential They pose a big challenge to our typing though they might get a lose AbstractObject typing in later versions
Joins Essential They were the subject of internal discussions, and we aim to support them in later versions
Configurable Encoding/Collation Essential We decided only to support utf8mb4_unicode_ci collation for simplicity's sake. We might add this much later
Unsigned Propery Essential We could offer this easily by simply plugging in the setting in the SQL Syntax and existing databases with unsigned columns already work. The Datatype ranges in Java, however, do not support it and can overflow. We want to introduce our own unsigned types later.

Current Design Flaws and architectural impurities

  • Relationships are not their own types, and their methods placed on the model
  • We don't treat exceptions soundly
  • An id field is currently necessary (we could dynamically go via the attributes primary key and unique and otherwise match all data with LIMIT 1)

Maven (Standalone Usage)

<repository>
    <id>javawebstack</id>
    <url>https://repo.javawebstack.org</url>
</repository>
<dependency>
    <groupId>org.javawebstack</groupId>
    <artifactId>ORM</artifactId>
    <version>1.0-SNAPSHOT</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.22</version>
</dependency>