Safe Haskell	None
Language	Haskell2010

Database.Beam.Migrate.Simple

Description

Utility functions for common use cases

Synopsis

autoMigrate :: ( Database be db, MonadFail m) => BeamMigrationBackend be m -> CheckedDatabaseSettings be db -> m ()
simpleSchema :: Database be db => ActionProvider be -> CheckedDatabaseSettings be db -> Maybe [ BeamSqlBackendSyntax be]
simpleMigration :: ( MonadBeam be m, Database be db) => ( forall a. handle -> m a -> IO a) -> BeamMigrationBackend be m -> handle -> CheckedDatabaseSettings be db -> IO ( Maybe [ BeamSqlBackendSyntax be])
runSimpleMigration :: MonadBeam be m => ( forall a. hdl -> m a -> IO a) -> hdl -> [ BeamSqlBackendSyntax be] -> IO ()
backendMigrationScript :: BeamSqlBackend be => ( BeamSqlBackendSyntax be -> String ) -> Migration be a -> String
data VerificationResult
- = VerificationSucceeded
- | VerificationFailed [ SomeDatabasePredicate ]
verifySchema :: ( Database be db, MonadBeam be m) => BeamMigrationBackend be m -> CheckedDatabaseSettings be db -> m VerificationResult
newtype IgnorePredicates = IgnorePredicates {
- unIgnorePredicates :: SomeDatabasePredicate -> Any
}
data CheckResult = CheckResult {
- missingPredicates :: HashSet SomeDatabasePredicate
- unexpectedPredicates :: HashSet SomeDatabasePredicate
}
ignoreTables :: ( QualifiedName -> Bool ) -> IgnorePredicates
ignoreAll :: IgnorePredicates
checkSchema :: ( Database be db, Monad m) => BeamMigrationBackend be m -> CheckedDatabaseSettings be db -> IgnorePredicates -> m CheckResult
createSchema :: ( Database be db, MonadFail m) => BeamMigrationBackend be m -> CheckedDatabaseSettings be db -> m ()
data BringUpToDateHooks m = BringUpToDateHooks {
- runIrreversibleHook :: m Bool
- startStepHook :: Int -> Text -> m ()
- endStepHook :: Int -> Text -> m ()
- runCommandHook :: Int -> String -> m ()
- queryFailedHook :: m ()
- discontinuousMigrationsHook :: Int -> m ()
- logMismatchHook :: Int -> Text -> Text -> m ()
- databaseAheadHook :: Int -> m ()
}
defaultUpToDateHooks :: MonadFail m => BringUpToDateHooks m
bringUpToDate :: ( Database be db, MonadFail m, HasDataTypeCreatedCheck ( BeamMigrateSqlBackendDataTypeSyntax be)) => BeamMigrationBackend be m -> MigrationSteps be () ( CheckedDatabaseSettings be db) -> m ( Maybe ( CheckedDatabaseSettings be db))
bringUpToDateWithHooks :: forall db be m. ( Database be db, MonadFail m, HasDataTypeCreatedCheck ( BeamMigrateSqlBackendDataTypeSyntax be)) => BringUpToDateHooks m -> BeamMigrationBackend be m -> MigrationSteps be () ( CheckedDatabaseSettings be db) -> m ( Maybe ( CheckedDatabaseSettings be db))
haskellSchema :: ( MonadBeam be m, MonadFail m) => BeamMigrationBackend be m -> m String
module Database.Beam.Migrate.Actions
module Database.Beam.Migrate.Types

Documentation

autoMigrate :: ( Database be db, MonadFail m) => BeamMigrationBackend be m -> CheckedDatabaseSettings be db -> m () Source #

Given a BeamMigrationBackend , attempt to automatically bring the current database up-to-date with the given CheckedDatabaseSettings . Fails (via fail ) if this involves an irreversible migration (one that may result in data loss).

simpleSchema :: Database be db => ActionProvider be -> CheckedDatabaseSettings be db -> Maybe [ BeamSqlBackendSyntax be] Source #

Attempt to find a SQL schema given an ActionProvider and a checked database. Returns Nothing if no schema could be found, which usually means you have chosen the wrong ActionProvider , or the backend you're using is buggy.

simpleMigration :: ( MonadBeam be m, Database be db) => ( forall a. handle -> m a -> IO a) -> BeamMigrationBackend be m -> handle -> CheckedDatabaseSettings be db -> IO ( Maybe [ BeamSqlBackendSyntax be]) Source #

Given a migration backend, a handle to a database, and a checked database, attempt to find a schema. This should always return Just , unless the backend has incomplete migrations support.

BeamMigrationBackend s can usually be found in a module named Database.Beam. Backend .Migrate with the name migrationBackend

runSimpleMigration :: MonadBeam be m => ( forall a. hdl -> m a -> IO a) -> hdl -> [ BeamSqlBackendSyntax be] -> IO () Source #

Run a sequence of commands on a database

backendMigrationScript :: BeamSqlBackend be => ( BeamSqlBackendSyntax be -> String ) -> Migration be a -> String Source #

Given a function to convert a command to a String , produce a script that will execute the given migration. Usually, the function you provide eventually calls displaySyntax to rendere the command.

data VerificationResult Source #

Result type for verifySchema

Constructors

VerificationSucceeded
VerificationFailed [ SomeDatabasePredicate ]

Instances

Instances details

Show VerificationResult Source #
Instance details Defined in Database.Beam.Migrate.Simple Methods showsPrec :: Int -> VerificationResult -> ShowS Source # show :: VerificationResult -> String Source # showList :: [ VerificationResult ] -> ShowS Source #

verifySchema :: ( Database be db, MonadBeam be m) => BeamMigrationBackend be m -> CheckedDatabaseSettings be db -> m VerificationResult Source #

Verify that the given, beam database matches the actual schema. On success, returns VerificationSucceeded , on failure, returns VerificationFailed and a list of missing predicates.

newtype IgnorePredicates Source #

Selects a class of predicates to ignore if detected (e.g. metadata tables for migrations, other schemas, etc.).

Constructors

IgnorePredicates
Fields unIgnorePredicates :: SomeDatabasePredicate -> Any

Instances

Instances details

Semigroup IgnorePredicates Source #
Instance details Defined in Database.Beam.Migrate.Simple Methods (<>) :: IgnorePredicates -> IgnorePredicates -> IgnorePredicates Source # sconcat :: NonEmpty IgnorePredicates -> IgnorePredicates Source # stimes :: Integral b => b -> IgnorePredicates -> IgnorePredicates Source #
Monoid IgnorePredicates Source #
Instance details Defined in Database.Beam.Migrate.Simple Methods mempty :: IgnorePredicates Source # mappend :: IgnorePredicates -> IgnorePredicates -> IgnorePredicates Source # mconcat :: [ IgnorePredicates ] -> IgnorePredicates Source #

data CheckResult Source #

Result type for checkSchema

Constructors

CheckResult
Fields missingPredicates :: HashSet SomeDatabasePredicate Expected predicates from the `CheckedDatabaseSettings` which were not found in the live database unexpectedPredicates :: HashSet SomeDatabasePredicate Predicates found in the live database which are not present in the `CheckedDatabaseSettings` and are not ignored

Instances

Instances details

Eq CheckResult Source #
Instance details Defined in Database.Beam.Migrate.Simple Methods (==) :: CheckResult -> CheckResult -> Bool Source # (/=) :: CheckResult -> CheckResult -> Bool Source #
Show CheckResult Source #
Instance details Defined in Database.Beam.Migrate.Simple Methods showsPrec :: Int -> CheckResult -> ShowS Source # show :: CheckResult -> String Source # showList :: [ CheckResult ] -> ShowS Source #

ignoreTables :: ( QualifiedName -> Bool ) -> IgnorePredicates Source #

Ignore predicates relating to tables matching the given name predicate.

ignoreAll :: IgnorePredicates Source #

Ignore any unknown predicates. This probably only makes sense to use if you are only querying and not writing to the database.

checkSchema :: ( Database be db, Monad m) => BeamMigrationBackend be m -> CheckedDatabaseSettings be db -> IgnorePredicates -> m CheckResult Source #

Checks the given database settings against the live database. This is similar to verifySchema , but detects and returns unknown predicates that are true about the live database (e.g. unknown tables, fields, etc.).

createSchema :: ( Database be db, MonadFail m) => BeamMigrationBackend be m -> CheckedDatabaseSettings be db -> m () Source #

Given a CheckedDatabaseSettings and a BeamMigrationBackend , attempt to create the schema from scratch in the current database.

May fail if we cannot find a schema

data BringUpToDateHooks m Source #

Constructors

BringUpToDateHooks

Fields

runIrreversibleHook :: m Bool

Called before we're about to run an irreversible migration step. Return True to run the step, or False to abort immediately.
startStepHook :: Int -> Text -> m ()

Called at the beginning of each step with the step index and description
endStepHook :: Int -> Text -> m ()

Called at the end of each step with the step index and description
runCommandHook :: Int -> String -> m ()

Called before a command is about to run. The first argument is the step index and the second is a string representing the command about to be run.
queryFailedHook :: m ()

Called when a query fails
discontinuousMigrationsHook :: Int -> m ()

Called when the migration log has a discontinuity at the supplied index
logMismatchHook :: Int -> Text -> Text -> m ()

The migration log at the given index is not what was expected. The first text is the actual commit id, the second, the expected
databaseAheadHook :: Int -> m ()

The database is ahead of the given migrations. The parameter supplies the number of entries passed the given migrations the database has.

defaultUpToDateHooks :: MonadFail m => BringUpToDateHooks m Source #

Default set of BringUpToDateHooks . Refuses to run irreversible migrations, and fails in case of error, using fail .

bringUpToDate :: ( Database be db, MonadFail m, HasDataTypeCreatedCheck ( BeamMigrateSqlBackendDataTypeSyntax be)) => BeamMigrationBackend be m -> MigrationSteps be () ( CheckedDatabaseSettings be db) -> m ( Maybe ( CheckedDatabaseSettings be db)) Source #

Equivalent to calling bringUpToDateWithHooks with defaultUpToDateHooks .

Tries to bring the database up to date, using the database log and the given MigrationSteps . Fails if the migration is irreversible, or an error occurs.

bringUpToDateWithHooks :: forall db be m. ( Database be db, MonadFail m, HasDataTypeCreatedCheck ( BeamMigrateSqlBackendDataTypeSyntax be)) => BringUpToDateHooks m -> BeamMigrationBackend be m -> MigrationSteps be () ( CheckedDatabaseSettings be db) -> m ( Maybe ( CheckedDatabaseSettings be db)) Source #

Check for the beam-migrate log. If it exists, use it and the supplied migrations to bring the database up-to-date. Otherwise, create the log and run all migrations.

Accepts a set of hooks that can be used to customize behavior. See the documentation for BringUpToDateHooks for more information. Calling this with defaultUpToDateHooks is the same as using bringUpToDate .

haskellSchema :: ( MonadBeam be m, MonadFail m) => BeamMigrationBackend be m -> m String Source #

Given a BeamMigrationBackend , get a string representing a Haskell module that would be a good starting point for further development.

For example, for a postgres database named chinook

import Database.Beam.Migrate.Simple
import Database.Beam.Postgres (runBeamPostgres)
import Database.Beam.Postgres.Migrate (migrationBackend)
import Database.PostgreSQL.Simple

getSchema :: IO String
getSchema = do pg <- connectPostgreSQL
               runBeamPostgres pg (haskellSchema migrationBackend)

Backends that have a migration backend typically export it under the module name Database.Beam. Backend .Migrate .

module Database.Beam.Migrate.Actions

module Database.Beam.Migrate.Types