Provides automatic encoder and decoder generation for "hasql", supporting all PostgreSQL types defined in the "postgresql-types" package. The standard "hasql" codecs use common Haskell types like Text, DiffTime, UTCTime, etc. However these types do not always map precisely to PostgreSQL types. E.g., the PostgreSQL interval type carries information about months, years and microseconds, while the Haskell DiffTime type only represents a time difference in picoseconds. Such mismatches can lead to data loss or unexpected behavior. The "postgresql-types" library addresses such issues by providing precise Haskell representations for PostgreSQL types. This package integrates it with "hasql". It also provides a class-based polymorphic interface for defining "hasql" Value codecs.