persistent-audit

This package includes an executable that takes a Persistent models (tables) file and returns a Persistent models file with audit models (tables) for each individual table in the original file. It can optionally return a file with an implementation of the ToAudit class for each pair of model and its audit model. The automatically produced audit model files and ToAudit instances are a best attempt and will not necessarily compile without editing. If you are interested in having different styles of Audit models supported or find any bugs, please inform me. It currently supports Persistent >= 2.2 && <= 2.5.

Cabal

The executable can be run like this:

Produce audit types

cabal run -- -m models -a auditModels

Produce audit types from Haskell file

It can also parse Haskell files that have Persist model QuasiQuoters [persistLowerCase||] and [persistUpperCase||]:

cabal run -- -m Models.hs -a auditModels

Produce ToAudit instances

And if you want the optional ToAudit implementation:

cabal run -- -m models -a auditModels -i ToAuditInstances.hs

Produce cross database ToAudit instances

It can also help you build Audit Models that will be used in a separate database (MongoDB to SQL or SQL to MongoDB) by converting MongoDB keys to Bytestring or SQL keys to Int64.

cabal run -- -m models -a auditModels -i ToAuditInstances.hs -c mongoDbToSql
cabal run -- -m models -a auditModels -i ToAuditInstances.hs -c sqlToMongoDb

Stack

Produce audit types

stack exec persistent-audit -- -m examples/models -a examples/auditModels

Produce audit types from Haskell file

stack exec persistent-audit -- -m examples/Models.hs -a examples/auditModels

Produce ToAudit instances

stack exec persistent-audit -- -m examples/models -a examples/auditModels -i examples/ToAuditInstances.hs

Produce cross database ToAudit instances

stack exec persistent-audit -- -m examples/models -a examples/auditModels -i examples/ToAuditInstances.hs -c mongoDbToSql
stack exec persistent-audit -- -m examples/models -a examples/auditModels -i examples/ToAuditInstances.hs -c sqlToMongoDb

Other use cases

You can also use this as a library for the following purporses:

• To parse Persistent model files
• To generate Audit Models from other Models
• To generate ToAudit instances
• Use query functions from Database.Persist.Audit.Queries:insertAndAudit, deleteAndAudit, deleteWhereAndAudit, updateAndAudit, updateWhereAndAudit, insertUniqueAndAudit, deleteByAndAudit, repsertAndAudit, replaceAndAudit

This package is originally based on this article Maintaining a Log of Database Changes. Specifically, the first example: 'A Separate "History" Table for Each Table Being Audited'.