docs: update readme

This commit is contained in:
Orion Kindel 2024-11-13 14:21:51 -06:00
parent f16a348414
commit 2d1f2e4695
Signed by untrusted user who does not match committer: orion
GPG Key ID: 6D4165AE4C928719

136
README.md
View File

@ -8,6 +8,7 @@ Purescript PostgreSQL driver
- [Ranges](#data---ranges)
- [Queries](#queries)
- [Builder](#queries---builder)
- [Errors](#errors)
- [Monads](#monads)
- [`PostgresT`](#monads---postgrest)
- [`SessionT`](#monads---sessiont)
@ -50,11 +51,12 @@ import Effect.Class (liftEffect)
import Effect.Aff (launchAff_)
import Effect.Console (log)
import Control.Monad.Postgres (runPostgres, query)
import Effect.Postgres.Error.Except as PG.X
main :: Effect Unit
main =
launchAff_ do
msg <- runPostgres pgConfig $ query "select 'hello, world!'"
msg <- PG.X.run $ runPostgres pgConfig $ query "select 'hello, world!'"
liftEffect $ log msg -- logs 'hello, world!'
```
@ -191,21 +193,37 @@ that will reference that value in the query.
[`Query.Builder.build`] renders the query to [`Query`]
## Errors
Errors are wrapped in [`Error`]:
```haskell
data Error
= Deserializing Query Foreign.MultipleErrors
| Serializing Foreign.MultipleErrors
| Executing Query Effect.Error
| Connecting Effect.Error
| Disconnecting Effect.Error
| Other Effect.Error
```
Most operations in this library return a [`Except`], which is just
`ExceptT` pinned to `NonEmptyArray Error`.
This can be unlifted to `Aff` with [`Except.run`].
## Monads
### Monads - `PostgresT`
[`PostgresT`] is the database driver's main entry point,
and is just an `Aff` with access to a [`Pool`].
[`PostgresT`] is a monadic context with a connection [`Pool`]. It allows running [`transaction`]s, simple [queries][`query`] and more.
Run in `Aff` with [`runPostgres`]:
#### Running in Aff
```purescript
main :: Effect Unit
main =
launchAff_ do
hi <- runPostgres {} $ query "select 'hi!'"
hi <- PG.X.run $ runPostgres {} $ query "select 'hi!'"
liftEffect $ log hi
```
Execute [`SessionT`] monads with [`session`] or [`transaction`]:
#### Executing a transaction
```purescript
dbMain :: PostgresT Aff Unit
dbMain = do
@ -220,7 +238,7 @@ dbMain = do
pure unit
```
Implements [`MonadSession`] as a shorthand for single-query [`session`]s:
#### Simple queries
```purescript
dbMain :: PostgresT Aff Int
dbMain = exec_ $ "insert into persons (name) values ($1);" /\ "Sarah"
@ -228,7 +246,7 @@ dbMain = exec_ $ "insert into persons (name) values ($1);" /\ "Sarah"
-- dbMain = session $ exec_ ...
```
Execute [`CursorT`] monads with [`cursor`]:
#### Executing cursor queries
```purescript
dbMain :: PostgresT Aff Int
dbMain =
@ -241,12 +259,12 @@ dbMain =
```
### Monads - `SessionT`
[`SessionT`] is an `Aff` with access to a [`Client`]
issued by a [`Pool`], connected to the database.
[`SessionT`] is a context that can run queries using a specific [`Client`].
Run in [`PostgresT`] with [`session`] or [`transaction`]
Sessions can be started in [`PostgresT`], which will ask the [`Pool`] for a [`Client`],
then release the [`Client`] after the session completes.
Perform queries with [`query`], [`exec`] or [`exec_`]
Within sessions, queries can be performed with [`query`], [`exec`] and [`exec_`].
### Monads - `CursorT`
[`CursorT`] is a transaction [`SessionT`] with access to a named server-side cursor.
@ -267,59 +285,63 @@ the api of [`node-postgres`]:
- release clients with [`Pool.release`] or [`Pool.destroy`]
- release with [`Pool.end`]
[`Pool`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Pool#t:Pool
[`Config`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Pool#t:Config
[`Pool.make`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Pool#v:make
[`Pool.end`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Pool#v:end
[`Pool.connect`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Pool#v:connect
[`Pool.destroy`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Pool#v:destroy
[`Pool.release`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Pool#v:release
[`Pool`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Pool#t:Pool
[`Config`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Pool#t:Config
[`Pool.make`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Pool#v:make
[`Pool.end`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Pool#v:end
[`Pool.connect`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Pool#v:connect
[`Pool.destroy`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Pool#v:destroy
[`Pool.release`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Pool#v:release
[`Client`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Client#t:Client
[`Client.end`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Client#v:end
[`Client.make`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Client#v:make
[`Client.connected`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Client#v:connected
[`Client.query`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Client#v:query
[`Client.queryRaw`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Client#v:queryRaw
[`Client.exec`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Effect.Aff.Postgres.Client#v:exec
[`Client`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Client#t:Client
[`Client.end`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Client#v:end
[`Client.make`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Client#v:make
[`Client.connected`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Client#v:connected
[`Client.query`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Client#v:query
[`Client.queryRaw`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Client#v:queryRaw
[`Client.exec`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Aff.Postgres.Client#v:exec
[`Range`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Range#t:Range
[`Range.gt`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Range#v:gt
[`Range.gte`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Range#v:gte
[`Range.lt`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Range#v:lt
[`Range.lte`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Range#v:lte
[`Range`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Range#t:Range
[`Range.gt`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Range#v:gt
[`Range.gte`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Range#v:gte
[`Range.lt`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Range#v:lt
[`Range.lte`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Range#v:lte
[`Raw`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Raw#t:Raw
[`Null`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Raw#t:Null
[`Raw`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Raw#t:Raw
[`Null`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Raw#t:Null
[`Serialize`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres#t:Serialize
[`Deserialize`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres#t:Deserialize
[`Rep`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres#t:Rep
[`modifyPgTypes`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres#v:modifyPgTypes
[`Serialize`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres#t:Serialize
[`Deserialize`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres#t:Deserialize
[`Rep`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres#t:Rep
[`modifyPgTypes`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres#v:modifyPgTypes
[`Result`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Result#t:Result
[`FromRow`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Result#t:FromRow
[`FromRows`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Result#t:FromRows
[`Result`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Result#t:Result
[`FromRow`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Result#t:FromRow
[`FromRows`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Result#t:FromRows
[`Query`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Query#t:Query
[`AsQuery`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Query#t:AsQuery
[`Query`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Query#t:Query
[`AsQuery`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Query#t:AsQuery
[`Query.Builder`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Query.Builder#t:Builder
[`Query.Builder.param`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Query.Builder#v:param
[`Query.Builder.build`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Data.Postgres.Query.Builder#v:build
[`Query.Builder`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Query.Builder#t:Builder
[`Query.Builder.param`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Query.Builder#v:param
[`Query.Builder.build`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Data.Postgres.Query.Builder#v:build
[`MonadCursor`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Control.Monad.Postgres#t:MonadCursor
[`MonadSession`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Control.Monad.Postgres#t:MonadSession
[`CursorT`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Control.Monad.Postgres#t:CursorT
[`SessionT`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Control.Monad.Postgres#t:SessionT
[`PostgresT`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Control.Monad.Postgres#t:PostgresT
[`cursor`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Control.Monad.Postgres#v:cursor
[`session`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Control.Monad.Postgres#v:session
[`transaction`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Control.Monad.Postgres#v:transaction
[`runPostgres`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Control.Monad.Postgres#v:runPostgres
[`query`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Control.Monad.Postgres#v:query
[`exec`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Control.Monad.Postgres#v:exec
[`exec_`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/Control.Monad.Postgres#v:exec_
[`Except`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Postgres.Error.Except#t:Except
[`Error`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Postgres.Error#t:Error
[`Except.run`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Effect.Postgres.Error.Except#v:run
[`MonadCursor`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Control.Monad.Postgres#t:MonadCursor
[`MonadSession`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Control.Monad.Postgres#t:MonadSession
[`CursorT`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Control.Monad.Postgres#t:CursorT
[`SessionT`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Control.Monad.Postgres#t:SessionT
[`PostgresT`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Control.Monad.Postgres#t:PostgresT
[`cursor`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Control.Monad.Postgres#v:cursor
[`session`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Control.Monad.Postgres#v:session
[`transaction`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Control.Monad.Postgres#v:transaction
[`runPostgres`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Control.Monad.Postgres#v:runPostgres
[`query`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Control.Monad.Postgres#v:query
[`exec`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Control.Monad.Postgres#v:exec
[`exec_`]: https://pursuit.purescript.org/packages/purescript-postgresql/2.0.19/docs/Control.Monad.Postgres#v:exec_
[`node-postgres`]: https://node-postgres.com/
[`pg-types`]: https://github.com/brianc/node-pg-types/