[FORMATTING] PostgreSQL: MERGE (PostgreSQL 15+) is not recognized #986

PostgreSQL has supported MERGE since version 15, but the postgresql dialect does not seem to know the statement: merge, matched and insert stay lower case with keywordCase: 'upper', and the clauses are not laid out the way MERGE is in plsql, transactsql or bigquery.

Input data

merge into stock as t using incoming as s on t.sku = s.sku when matched then update set qty = s.qty when not matched then insert (sku, qty) values (s.sku, s.qty);

Expected Output (roughly what other dialects produce)

MERGE INTO
  stock AS t USING incoming AS s ON t.sku = s.sku
WHEN MATCHED THEN
UPDATE SET
  qty = s.qty
WHEN NOT MATCHED THEN
INSERT
  (sku, qty)
VALUES
  (s.sku, s.qty);

Actual Output

merge INTO stock AS t USING incoming AS s ON t.sku = s.sku WHEN matched THEN
UPDATE
SET
  qty = s.qty WHEN NOT matched THEN insert (sku, qty)
VALUES
  (s.sku, s.qty);

Reference: https://www.postgresql.org/docs/current/sql-merge.html

Usage

• Calling format() from the npm package directly (Node.js), options { language: ..., keywordCase: 'upper' }.
• SQL language(s): postgresql
• SQL Formatter version: 15.9.0 (also reproduced on 15.6.12)