From 4ff1aaedc29c65fca49d93fb781e3cc7d7006fba Mon Sep 17 00:00:00 2001 From: Yorick Peterse Date: Fri, 2 Jun 2017 14:34:26 +0200 Subject: Document not using STI --- doc/development/README.md | 1 + doc/development/single_table_inheritance.md | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+) create mode 100644 doc/development/single_table_inheritance.md diff --git a/doc/development/README.md b/doc/development/README.md index 83eef9dadc3..40addfd8a4c 100644 --- a/doc/development/README.md +++ b/doc/development/README.md @@ -52,6 +52,7 @@ - [Foreign Keys & Associations](foreign_keys.md) - [Serializing Data](serializing_data.md) - [Polymorphic Associations](polymorphic_associations.md) +- [Single Table Inheritance](single_table_inheritance.md) ## i18n diff --git a/doc/development/single_table_inheritance.md b/doc/development/single_table_inheritance.md new file mode 100644 index 00000000000..27c3c4f3199 --- /dev/null +++ b/doc/development/single_table_inheritance.md @@ -0,0 +1,18 @@ +# Single Table Inheritance + +**Summary:** don't use Single Table Inheritance (STI), use separate tables +instead. + +Rails makes it possible to have multiple models stored in the same table and map +these rows to the correct models using a `type` column. This can be used to for +example store two different types of SSH keys in the same table. + +While tempting to use one should avoid this at all costs for the same reasons as +outlined in the document ["Polymorphic Associations"](polymorphic_associations.md). + +## Solution + +The solution is very simple: just use a separate table for every type you'd +otherwise store in the same table. For example, instead of having a `keys` table +with `type` set to either `Key` or `DeployKey` you'd have two separate tables: +`keys` and `deploy_keys`. -- cgit v1.2.1