feat(ogar-adapter-clickhouse-ddl): scaffold ClickHouse DDL adapter — Phase 2b

[AdaWorldAPI]

Summary

New crate crates/ogar-adapter-clickhouse-ddl — third source-language adapter in OGAR's brutal-upgrade ingestion lineup. Composes with bardioc PR #19's substrate-b-shadow — same Class IR as the schema model their EdgeDecoder interprets rows against.

source dialect	adapter	direction
SurrealQL DDL	ogar-adapter-surrealql	parse + emit (PR #32)
Turtle (RDF/OWL)	ogar-adapter-ttl	parse + emit (PR #37)
ClickHouse DDL	ogar-adapter-clickhouse-ddl (this PR)	parse + emit

Data flow it completes

ClickHouse CREATE TABLE  ──▶  [this adapter]  ──▶  Class IR (schema)
                                                          │
ClickHouse rows (RowBinary) ──▶ [substrate-b-shadow      │  schema
                                 EdgeDecoder] ─▶ ActionInvocation
                                                          │
                                          interprets ─────┘

Per ADR-023 (IR-as-wire-truth) the shared substrate is OGAR Class.

Type mapping (ClickHouse ⇄ OGAR canonical)

Normalized to OGAR's canonical lexicon — same set used by ogar-adapter-surrealql. A Class IR survives a SurrealQL → OGAR → ClickHouse → OGAR cycle byte-identical on the type axis.

ClickHouse	OGAR type_name
String, FixedString(N)	string
UInt8/16/32/64, Int8/16/32/64	int
Float32, Float64	float
Decimal(P,S)	decimal
DateTime, DateTime64, Date	datetime
Bool	bool
UUID	uuid
Nullable(<inner>)	inner + options.required = Some(false)
anything else	any

Emit reverses with default widths (Int64 / Float64 / Decimal(18, 4) / DateTime) — AR-pattern-sufficient.

Parse implementation

Uses sqlparser 0.59 with ClickHouseDialect. Earlier versions (≤ 0.50) choke on Nullable(X) in CREATE TABLE — probed before adopting. The walker:

1. Drives Parser::parse_sql(&ClickHouseDialect, input)
2. Filters for Statement::CreateTable
3. Each ColumnDef → Attribute via clickhouse_type_to_ogar; Nullable(X) stripped recursively (ClickHouse forbids nested Nullable)
4. ORDER BY lifts to Class.record_order when scalar
5. Lowercase-prefix family matching keeps type recognition robust across UInt8/16/32/64, Int8/16/32/64, Float32/64, DateTime/DateTime64 etc. without enumerating sqlparser variants

Identifier quoting

quote_ch_ident() — bare for [A-Za-z_][A-Za-z0-9_]*, backtick-quoted otherwise. Same discipline as ogar-adapter-surrealql's surrealql_ident — Odoo dotted names (sale.order) work across all three adapters consistently.

Tests (12 — 7 emit always, 5 parse + round-trip behind feature)

Emit (always):

• emit_minimal_class_produces_create_table_mergetree
• emit_class_with_string_column
• emit_class_with_optional_column_wraps_with_nullable
• emit_class_with_record_order_lifts_to_order_by
• emit_quotes_non_bare_table_name
• emit_full_class_with_multiple_columns
• parse_returns_unimplemented_when_feature_off

Parse + round-trip (clickhouse-parser):

• parse_minimal_create_table_lifts_one_class
• parse_nullable_lifts_to_required_false — IR-canonical shape
• parse_recognizes_type_families — all 9 type families
• parse_rejects_invalid_ddl
• round_trip_simple_class_preserves_attributes — load-bearing
• round_trip_optional_primitive — Nullable round-trip

Workspace + CI

• Cargo.toml: added crates/ogar-adapter-clickhouse-ddl to workspace members
• .github/workflows/ci.yml: added cargo test -p ogar-adapter-clickhouse-ddl --features clickhouse-parser — same crate-scoped pattern as the other feature-gated adapter test steps

Verification

$ cargo test --workspace                                            -> clean
$ cargo test -p ogar-adapter-clickhouse-ddl                         -> 7/7
$ cargo test -p ogar-adapter-clickhouse-ddl --features clickhouse-parser -> 12/12
$ cargo check --workspace --all-targets                             -> clean
$ cargo test -p ogar-adapter-surrealql --features surrealdb-parser  -> 33/33
$ cargo test -p ogar-adapter-ttl --features ttl-parser              -> 9/9
$ cargo test -p ogar-knowable-from --features surrealql-hint        -> 10/10

PII abort-guard (word-boundary): CLEAN.

Position in sequencing

Phase	Status
Phase 1 (#30) — RDF-OWL-ALIGNMENT doc	✅ merged
Phase 2a (#37) — ogar-adapter-ttl scaffold	✅ merged
Phase 2b (this) — ogar-adapter-clickhouse-ddl scaffold	opens
Phase 2b — ogar-from-ecto	queued
Phase 3 — VART backend on ogar-knowable-from	queued
Phase 4+ — ogar-pattern, ogar-actionable, ...	queued

https://claude.ai/code/session_01PBTGaPCSnnt6u3pjXpbLwY

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Preserve quoted dotted table names on parse

When parsing a table emitted from a dotted class name such as Class::new("sale.order"), the emitter produces CREATE TABLE sale.order ..., but this path converts the parsed name to a string and last_ident then splits on . before trimming backticks. That round-trip recovers the class name as order instead of sale.order, breaking the stated support for Odoo dotted names and losing schema identity whenever those emitted DDL statements are parsed back.

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