Add functions that let you do pre- and post- auto-migration hooks that run in the same transaction

.gitignore

@@ -6,3 +6,5 @@ hie.yaml
 *.prof
 .stack-work
 cabal.project.freeze
+
+readme-db

CHANGELOG.md

@@ -1,5 +1,18 @@
 # Revision history for beam-automigrate
 
+## Unreleased
+
+* Added runMigrationsWithEditUpdateAndHooks and tryRunMigrationsWithEditUpdateAndHooks, that take Pg actions to run before and after the auto-migration in the same transaction.
+* Major overhaul in how constraints and sequences are diffed
+  * haskell/database constraints are now diffed based on *what* they constrain; instead of being an exact match.  inconsequential differences (in particular, the names of constraints, in most cases) no longer require any expensive DML.
+  * Sequences ownership is now handled with the `OWNED BY table_name.column_name` mechanism instead of parsing the owner out of the sequence name.  unowned sequences (which might be used for purposes other than surrogate keys, for example) are still supported internally.
+  * beam-automigrate will now allow postgres to choose the names of constraints and sequences when possible.  In cases where that's not possible or desired, there is now a straightforward mechanism for end users to specify the name explicitly (see `foreignKeyWithOptions`).
+  * constraint options are always optional, with `Default` instances for `UniqueConstraintOptions` and `ForeignKeyConstraintOptions`.  As of this writing, the defaults currently mean "let postgres decide" for constraint names and cascade behaviors (the latter being NO ACTION).
+  * Foreign keys can now be configured to reference columns that are different from the table's primary key.  in general this feature is much easier to use; passing a function that projects out the desired columns from both tables.
+  * foreign keys can now be partially nullable. (see `foreignKeyOnNullable`)
+  * Many instances of database entities being dropped and recreated instead of altered are now supported.
+* [#47](https://github.com/obsidiansystems/beam-automigrate/pull/47): Generate postgres enum types in schema when using `Nullable PgEnum` values.
+
 ## 0.1.6.0
 
 * Fix instance HasSchemaConstraints build failure with GHC 9.2.8

README.md

@@ -9,18 +9,19 @@ Automatic migrations for [beam](https://hackage.haskell.org/package/beam-core) d
 Table of Contents
 -----------------
 
-* [Table of Contents](#table-of-contents)
-* [Getting started (User guide/reference)](#getting-started-user-guidereference)
-   * [Deriving an AnnotatedDatabaseSettings](#deriving-an-annotateddatabasesettings)
-   * [Overriding the defaults of an AnnotatedDatabaseSettings](#overriding-the-defaults-of-an-annotateddatabasesettings)
-   * [Deriving a Schema](#deriving-a-schema)
-   * [Generating an automatic migration](#generating-an-automatic-migration)
-* [Current design (10_000ft overview)](#current-design-10_000ft-overview)
-   * [Deriving information from a DatabaseSettings](#deriving-information-from-a-databasesettings)
-   * [Deriving information from an AnnotatedDatabaseSettings](#deriving-information-from-an-annotateddatabasesettings)
-   * [What is implemented](#what-is-implemented)
-   * [Shortcomings and limitations](#shortcomings-and-limitations)
-* [Contributors](#contributors)
+- [beam-automigrate](#beam-automigrate)
+  - [Table of Contents](#table-of-contents)
+- [Getting started (User guide/reference)](#getting-started-user-guidereference)
+  - [Deriving an AnnotatedDatabaseSettings](#deriving-an-annotateddatabasesettings)
+  - [Overriding the defaults of an `AnnotatedDatabaseSettings`](#overriding-the-defaults-of-an-annotateddatabasesettings)
+  - [Deriving a Schema](#deriving-a-schema)
+  - [Generating an automatic migration](#generating-an-automatic-migration)
+- [Current design (10_000ft overview)](#current-design-10_000ft-overview)
+  - [Deriving information from a DatabaseSettings](#deriving-information-from-a-databasesettings)
+  - [Deriving information from an AnnotatedDatabaseSettings](#deriving-information-from-an-annotateddatabasesettings)
+  - [What is implemented](#what-is-implemented)
+  - [Shortcomings and limitations](#shortcomings-and-limitations)
+- [Contributors](#contributors)
 
 Getting started (User guide/reference)
 ======================================
@@ -64,11 +65,12 @@ Deriving an `AnnotatedDatabaseSettings` for a Haskell database type is a matter
 > import Data.Proxy (Proxy(..))
 > import Database.Beam.Postgres
 > import Database.Beam.Schema
-> import Database.Beam (val_)
+> import Database.Beam (val_, primaryKey)
 > import qualified Database.Beam.AutoMigrate as BA
 > import Database.Beam.AutoMigrate.TestUtils
 > import Database.PostgreSQL.Simple as Pg
 > import GHC.Generics
+> import Data.Default.Class
 > import Data.Text
 > import System.Environment (getArgs)
 >
@@ -132,7 +134,7 @@ ambiguity). To do this, we can piggyback on the familiar API from `beam-core`. F
 >       BA.annotateTableFields tableModification { ctCapital = BA.defaultsTo $ val_ False }
 >         <> BA.uniqueConstraintOn [BA.U ctCity, BA.U ctLocation]
 >   , dbWeathers = BA.annotateTableFields tableModification <>
->       BA.foreignKeyOnPk (dbCities defaultDbSettings) wtCity BA.Cascade BA.Restrict
+>       BA.foreignKeyOnWithOptions (dbCities defaultDbSettings) wtCity primaryKey def { BA.onDelete = BA.Cascade, BA.onUpdate = BA.Restrict}
 >   }
 
 ```
@@ -268,7 +270,7 @@ something like this:
 >
 > exampleAutoMigration :: Connection -> IO ()
 > exampleAutoMigration conn =
->   BA.tryRunMigrationsWithEditUpdate annotatedDB conn
+>   BA.tryRunMigrationsWithEditUpdate Prelude.id hsSchema conn
 >
 > main :: IO ()
 > main = do

beam-automigrate.cabal

@@ -37,6 +37,7 @@ library
     Database.Beam.AutoMigrate.Types
     Database.Beam.AutoMigrate.Util
     Database.Beam.AutoMigrate.Validity
+    Database.Beam.AutoMigrate.Parser
 
   hs-source-dirs:     src
   build-depends:
@@ -48,7 +49,6 @@ library
     , containers            >=0.5.9.2  && <0.8.0.0
     , deepseq               >=1.4.4    && <1.6
     , dlist                 >=0.8.0    && <1.1
-    , microlens             >=0.4.10   && <0.6
     , mtl                   >=2.2.2    && <2.4
     , postgresql-simple     >=0.5.4    && <0.7.0.0
     , pretty-simple         >=2.2.0    && <4.2
@@ -62,6 +62,10 @@ library
     , transformers          >=0.5.6    && <0.7
     , uuid                  >=1.3      && <1.4
     , vector                >=0.12.0.3 && <0.13.0.0
+    , lens
+    , data-default-class
+    , attoparsec
+    , parsers
 
   default-language:   Haskell2010
   default-extensions:
@@ -154,6 +158,7 @@ executable beam-automigrate-examples
     , beam-core
     , beam-postgres
     , bytestring
+    , data-default-class
     , postgresql-simple
     , text
     , time
@@ -219,6 +224,8 @@ executable readme
     , beam-automigrate-test-utils
     , beam-core
     , beam-postgres
+    , data-default-class
+    , gargoyle-postgresql-connect
     , postgresql-simple
     , text
   default-language: Haskell2010

cabal.project

@@ -1 +1,20 @@
 packages: .
+
+source-repository-package
+    type: git
+    location: https://github.com/obsidiansystems/beam.git
+    -- branch dylang/sql-deconstruct-maybe
+    tag: 9b6bf4f846869223737131999ceec16e8eb79ef8
+    subdir:
+      beam-core
+      beam-postgres
+      beam-migrate
+
+source-repository-package
+    type: git
+    location: https://github.com/obsidiansystems/postgresql-simple.git
+    -- branch dylang/synthesizable-fields-2
+    tag: 2a3e5210f87628eaa5d7a51d17211e84a5acd13b
+
+allow-older:
+    postgresql-simple

examples/Example.hs

@@ -14,6 +14,7 @@ module Example where
 import Control.Exception
 import Data.Aeson.TH
 import Data.ByteString (ByteString)
+import Data.Default.Class
 import Data.Int (Int32, Int64)
 import Data.Proxy
 import Data.Text (Text)
@@ -32,6 +33,8 @@ import Database.Beam.AutoMigrate
     migrate,
     printMigration,
     unsafeRunMigration,
+    onUpdate,
+    onDelete,
   )
 import Database.Beam.AutoMigrate.Annotated
 import Database.Beam.AutoMigrate.Postgres (getSchema)
@@ -208,7 +211,7 @@ annotatedDB =
               { orderTime = defaultsTo currentTimestamp_,
                 orderValidity = defaultsTo (range_ Inclusive Inclusive (val_ $ Just 10) (val_ $ Just 20))
               }
-            <> foreignKeyOnPk (dbFlowers flowerDB) orderFlowerIdRef Cascade Restrict
+            <> foreignKeyOnWithOptions (dbFlowers flowerDB) orderFlowerIdRef primaryKey (def { onUpdate = Cascade, onDelete = Restrict })
             <> uniqueConstraintOn [U (addressPostalCode . addressRegion . orderAddress)]
             --, dbLineItemsTwo = foreignKeyOn (dbLineItems flowerDB) [
             --                          lineItemTwoFk `References` LineItemID

integration-tests/Main.hs

@@ -23,7 +23,6 @@ import Data.Generics.Aliases (mkT)
 import Data.Generics.Schemes (everywhere)
 import Data.Int
 import qualified Data.Map as Map
-import qualified Data.Set as Set
 import Data.Text (Text)
 import qualified Data.Text as T
 import PostgresqlSyntax.Ast
@@ -82,12 +81,15 @@ instance NormalizeDefaultExprs Table where
   normalizeDefaultExprs t = t { tableColumns = Map.map normalizeDefaultExprs (tableColumns t)}
 
 instance NormalizeDefaultExprs Column where
-  normalizeDefaultExprs c = c { columnConstraints = Set.map normalizeDefaultExprs (columnConstraints c) }
+  normalizeDefaultExprs c = c { columnConstraints = normalizeDefaultExprs (columnConstraints c) }
 
-instance NormalizeDefaultExprs ColumnConstraint where
+instance NormalizeDefaultExprs ColumnConstraints where
+  normalizeDefaultExprs c =  c { columnDefault = fmap normalizeDefaultExprs (columnDefault c) }
+
+instance NormalizeDefaultExprs DefaultConstraint where
   normalizeDefaultExprs = \case
-    NotNull -> NotNull
-    Default t -> Default (normalizeDefaultExpr t)
+    DefaultExpr t -> DefaultExpr $ normalizeDefaultExpr t
+    Autoincrement mseq -> Autoincrement mseq
 
 normalizeDefaultExpr :: Text -> Text
 normalizeDefaultExpr t = case PgParsing.run PgParsing.aExpr t of