Migration to 1.0

Cornucopia 1.0 is a major release that adopts the work from the Clorinde fork (which was itself derived from Cornucopia 0.9). The two codebases have rejoined under the cornucopia name. This page describes the breaking changes you'll encounter when upgrading from Cornucopia 0.9.x.

Crate-based code generation

Cornucopia generates a crate instead of a single file which allows it to automatically generate a Cargo.toml file customised to support all the necessary dependencies and features required by your queries, without polluting your manifest. For example, Cornucopia's "Full dependencies" example:

[dependencies]
# Required
postgres-types = { version = "*", features = ["derive"] }

# Async
cornucopia_async = { version = "*", features = ["with-serde_json-1"] }
tokio = { version = "*", features = ["full"] }
tokio-postgres = { version = "*", features = [
    "with-serde_json-1",
    "with-time-0_3",
    "with-uuid-1",
    "with-eui48-1",
] }
futures = "*"
# Async connection pooling
deadpool-postgres = { version = "*" }

# Row serialization
serde = { version = "*", features = ["derive"] }

# Extra types
serde_json = "*"
time = "*"
uuid = "*"
eui48 = "*"
rust_decimal = { version = "*", features = ["db-postgres"] }

Could be replaced with:

[dependencies]
cornucopia = { path = "cornucopia" }

Cornucopia also re-exports the dependencies: postgres, tokio-postgres, and deadpool-postgres.

A drawback to crate-based code generation is that cargo won't publish crates with path dependencies meaning you either can't publish a crate that depends on Cornucopia or you will need to publish the Cornucopia crate separately.

If doing the latter, you can use a cornucopia.toml to specify the [manifest.package] section of the Cargo.toml in the generated crate. For example, a cornucopia.toml that includes:

[manifest.package]
name = "my-cornucopia-queries"
version = "0.1.0"
license = "MIT"
homepage = "https://github.com/furina/my-repo"
repository = "https://github.com/furina/my-repo"
publish = true

Will generate cornucopia/Cargo.toml with the specified [package] where you can then publish the crate as my-cornucopia-queries.

chrono instead of time

Cornucopia uses the chrono crate instead of time. If you want to keep using time, use "Custom Type Mappings" to map the Postgres types to the time crate.

[types.mapping]
"pg_catalog.timestamp" = "time::PrimitiveDateTime"
"pg_catalog.timestamptz" = "time::OffsetDateTime"
"pg_catalog.time" = "time::Time"
"pg_catalog.date" = "time::Date"

[manifest.dependencies]
time = { version = "0.3", features = ["serde"] }
# enable the time feature of postgres and tokio-postgres
postgres = { version = "0.19", features = [
    "with-time-0_3",
    "with-serde_json-1",
] }
tokio-postgres = { version = "0.7", features = [
    "with-time-0_3",
    "with-serde_json-1",
] }