Converts a type specification to a PostgreSQL cast string.

Parameters

• type - A type specification, which can be:
  • An atom representing a basic PostgreSQL type
  • A tuple {:array, type} for array types
  • A tuple {:enum, name} for enum types

Returns

A string representation of the PostgreSQL cast type.

Examples

Basic types:

iex> Electric.Replication.Eval.type_to_pg_cast(:int4)
"int4"

iex> Electric.Replication.Eval.type_to_pg_cast(:text)
"text"

iex> Electric.Replication.Eval.type_to_pg_cast(:bool)
"bool"

Array types:

iex> Electric.Replication.Eval.type_to_pg_cast({:array, :int4})
"int4[]"

iex> Electric.Replication.Eval.type_to_pg_cast({:array, :text})
"text[]"

Nested array types:

iex> Electric.Replication.Eval.type_to_pg_cast({:array, {:array, :int4}})
"int4[]"

Enum types:

iex> Electric.Replication.Eval.type_to_pg_cast({:enum, :my_enum})
"my_enum"

iex> Electric.Replication.Eval.type_to_pg_cast({:enum, "custom_enum"})
"custom_enum"

Unsupported types raise errors:

iex> Electric.Replication.Eval.type_to_pg_cast({:row, []})
** (RuntimeError) Unsupported type: row

iex> Electric.Replication.Eval.type_to_pg_cast({:internal, :something})
** (RuntimeError) Unsupported type: internal

Convert a value from the eval representation to the format Postgrex expects for binary protocol encoding.

Most types (integers, floats, booleans, dates, times, etc.) use native Elixir types that Postgrex handles directly. UUID is a notable exception: the eval system stores UUIDs as human-readable strings, but Postgrex expects 16-byte raw binaries.