Pipes.PostgreSQL.Simple

Pipes utilities built on top of postgresql-simple

Querying

query :: (MonadIO m, FromRow r, ToRow params) => Connection -> Query -> params -> Producer r m ()

Convert a query to a Producer of rows.

For example,

 pg <- connectToPostgresql
 query pg "SELECT * FROM widgets WHERE ID = ?" (Only widgetId) >-> print

Will select all widgets for a given widgetId, and then print each row to standard output.

query_ :: (MonadIO m, FromRow r) => Connection -> Query -> Producer r m ()

Like query, but it doesn't perform any query parameter substitution.

Serialization and Deserialization

data Format

The PostgreSQL file format, used by the COPY command

Constructors

Text

Binary

CSV

Instances

Show Format

fromTable :: MonadIO m => Connection -> Format -> String -> Producer ByteString m Int64

Convert a table to a byte stream. This is equivilent to a PostgreSQL COPY ... TO statement.

Returns the number of rows processed.

toTable :: (MonadCatch m, MonadIO m) => Connection -> Format -> String -> Producer ByteString m () -> m Int64

Convert a byte stream to a table. This is equivilent to a PostgreSQL COPY ... FROM statement.

Returns the number of rows processed