datahike.pg.sql.ddl — org.replikativ/pg-datahike 0.1.60

DDL translation: CREATE TABLE, CREATE SEQUENCE, constraint extraction.

Produces Datahike tx-data that installs schema attributes (:db/ident, :db/valueType, :db/cardinality, :db/unique, :pg/type, and the pgwire-specific :pg/* constraint metadata).

The predicate helpers (identity-column?, column-is-primary-key?, column-is-unique?, column-is-not-null?, specs-contain-seq?, column-check-expr-text, column-default-spec) walk JSqlParser's ColumnDefinition.getColumnSpecs lists, which are raw strings — so each predicate is a case-insensitive token matcher.

Entry points:

• translate-create-table — main; returns {:type :ddl :tx-data [...]}
• translate-create-sequence — CREATE SEQUENCE name [...]

Helpers:

• extract-ddl-constraints — CHECK / NOT NULL / UNIQUE / FK clauses
• extract-inherits — PostgreSQL INHERITS

column-check-expr-text clj

(column-check-expr-text col)

Extract the text of an inline CHECK (…) constraint from a ColumnDefinition's ColumnSpecs, or nil if none.

JSqlParser emits inline CHECK as two tokens: CHECK and a second token that's the entire parenthesized expression, e.g. ["CHECK" "(x > 0)"]. We keep the inner text.

Also tolerate the tokenized form PG dialect dumps sometimes produce — CHECK followed by (, individual tokens, ) — by paren-matching across the remaining specs.

column-default-spec clj

(column-default-spec col)

If the column spec list carries DEFAULT <expr>, return a map describing the default so translate-create-table can attach it to the schema entity. Shape:

{:kind :literal :value <long|double|string|boolean|nil>} {:kind :fn :value <canonical fn name string>} {:kind :nextval :value <sequence name string>} {:kind :unsupported :raw <original SQL text>}

The literal branch handles numbers, single-quoted strings, boolean keywords, and NULL. The :fn branch covers the stateless current-* functions PG users rely on. :nextval is the only stateful default we support and it ties into our existing sequence infrastructure. Unknown expressions land in :unsupported so CREATE TABLE can raise loudly instead of silently dropping the constraint.

Walks the ColumnSpecs as whitespace-separated tokens; tolerant of parens (e.g. DEFAULT (now())).

column-is-not-null? clj

(column-is-not-null? col)

True when the column-spec list carries NOT NULL. PK columns are implicitly NOT NULL in PG; callers should combine this with column-is-primary-key? to avoid double-flagging.

column-is-primary-key? clj

(column-is-primary-key? col)

True when a column has inline PRIMARY KEY in its column specs.

column-is-unique? clj

(column-is-unique? col)

True when a column has inline UNIQUE in its column specs (not part of PRIMARY KEY, which we handle separately).

extract-ddl-constraints clj

(extract-ddl-constraints ct)

Collect PRIMARY KEY and UNIQUE constraints from a CreateTable into a normalized shape. Merges column-level specs (id INT PRIMARY KEY) with table-level indexes (PRIMARY KEY (a,b), UNIQUE (c)).

Returns a map: :pk-cols — vector of column names in the PK (empty if none) :pk-name — explicit constraint name for the PK, or nil :uniques — vector of {:cols [str...] :name str-or-nil} each an independent UNIQUE constraint Column names are the raw SQL idents (unquoted), not namespaced keywords. The caller owns the :t/col namespace mapping.

extract-inherits clj

(extract-inherits ct)

Extract parent table name from INHERITS clause in CREATE TABLE options.

identity-column? clj

(identity-column? col)

Check if a JSqlParser ColumnDefinition has GENERATED BY DEFAULT AS IDENTITY or uses a SERIAL type (which implies auto-increment).

sequence-entity clj

(sequence-entity seq-name
                 {:keys [increment minvalue maxvalue start cache cycle? type]})

The stored entity for a sequence with the given resolved params.

:__seq__/value holds the last value HANDED OUT, so a fresh sequence stores start - increment and the first advance lands exactly on start. (PG models this as last_value + is_called=false; the offset encoding is equivalent for a single-value-at-a-time nextval and is what the IDENTITY path in translate-create-table already assumes.)

sequence-params clj

(sequence-params opts {:keys [existing]})

Resolve a classifier option list into concrete sequence parameters, applying PG's defaults and raising PG's errors.

Mirrors init_params (postgres src/backend/commands/sequence.c:1260) including its ORDER, because a statement with more than one problem must report the same one PG reports: duplicate detection, then AS, INCREMENT, CYCLE, MAXVALUE, MINVALUE, the min/max crosscheck, START, RESTART, CACHE.

existing is the current parameter map for ALTER (nil for CREATE); options left unspecified keep their existing values on ALTER and take the defaults on CREATE.

Returns {:type :increment :minvalue :maxvalue :start :cache :cycle? :restart :owned-by}.

sequence-schema clj

Schema attributes backing a sequence entity. Idempotent — re-transacted on every CREATE SEQUENCE.

specs-contain-seq? clj

(specs-contain-seq? specs tokens)

True when the whitespace-split column-spec list contains the given token sequence contiguously, case-insensitive. Used to detect PRIMARY KEY (two tokens) and UNIQUE (one token) inline on a ColumnDefinition.

translate-create-sequence clj

(translate-create-sequence {:keys [seq-name seq-opts if-not-exists?]})

Translate a classified CREATE SEQUENCE into schema + initial entity.

Consumes the token classifier's :seq-opts rather than JSqlParser's AST: the grammar there covers only a subset of PG's option list, and the values used to be recovered by regex over the re-rendered SQL (increment\s+by\s+(\d+)), which could not see a negative increment and silently dropped MINVALUE/MAXVALUE/CACHE/CYCLE. See issue #21.

translate-create-table clj

(translate-create-table ct db)

Translate a CREATE TABLE statement to Datahike schema transaction data. Also returns :table-name, :column-order, :identity-cols, and :inherits.