Wiki source code of WebObjects and Squeryl
Version 93.1 by Ravi Mendis on 2010/11/10 04:58
Hide last authors
| author | version | line-number | content |
|---|---|---|---|
 |
81.1 | 1 | = Squeryl ~= //SQL-like// DSL for Scala = |
| |
54.1 | 2 | |
| |
85.1 | 3 | Advantages of Squeryl over EOF: |
| |
54.1 | 4 | |
| 5 | * Concurrent | ||
| 6 | ** Spawns multiple database connections | ||
| 7 | ** Issues database transactions concurrently | ||
| 8 | * Scala Actor compatible | ||
| 9 | ** Immutable object model/graph | ||
| |
81.1 | 10 | * Strongly-typed |
| |
54.1 | 11 | ** Better suited for database/business "logic". |
| 12 | E.g: Exploits the compiler and IDE to catch exceptions at compile time rather than at run-time. | ||
| |
85.1 | 13 | * Uses Scala (functional) collection classes |
| |
54.1 | 14 | |
| 15 | = Migrating EOF -> Squeryl = | ||
| 16 | |||
| |
93.1 | 17 | In contrast to EOF Squeryl maintains its ORM information programmatically - in the classes itself and collectively in a ##schema##. And in keeping with the strongly-typed philosophy of Scala, it has no dynamic component like EOF (i.e an EO model file). |
| |
54.1 | 18 | |
| |
85.1 | 19 | EOF has the ability to generate classes in Java (and in Objective-C prior to WebObjects 4.5) as enforcing type has become customary in enterprise environments. We may exploit this feature of EOF to generate a Squeryl schema. |
| |
54.1 | 20 | |
| 21 | === Preparing your EO model === | ||
| 22 | |||
| |
85.1 | 23 | * Make sure **all** EO entities have a class name (including abstract many-To-many "join" tables). There's no support for entities marked as ##EOGenericRecord##. |
| |
91.1 | 24 | * Mark the abstract many-To-Many join entities as ##Abstract##. |
| |
85.1 | 25 | * (Temporary) Ensure all the model entities are in the same package. i.e ##model## <-> ##package## corresponds 1-to-1. |
| |
54.1 | 26 | |
| 27 | === Generating the Squeryl Schema === | ||
| 28 | |||
| 29 | 1. Create a .eogen file for your EO model as normal. Only set the ##File Names## extension to "scala". | ||
| 30 | 1. Use the Squeryl EO Templates: | ||
| 31 | |||
| 32 | * | ||
| 33 | ** Entity.eotemplate [[template>>WOL:Squeryl _Entity.eotemplate]] | ||
| 34 | ** Entity.eotemplate [[template>>WOL:Squeryl Entity.eotemplate]] | ||
| 35 | |||
| 36 | {{note title="Note"}} | ||
| 37 | |||
| 38 | Any custom business "logic" will have to be manually re-written in Scala | ||
| 39 | |||
| 40 | {{/note}} |