fix signups sequence

Author: jackharrhy

src/where_the_plow/migrations/006_add_signup_name.py

@@ -21,7 +21,14 @@ def _has_column(conn: duckdb.DuckDBPyConnection, table: str, column: str) -> boo
 
 def upgrade(conn: duckdb.DuckDBPyConnection) -> None:
     if not _has_column(conn, "signups", "name"):
-        conn.execute("CREATE SEQUENCE IF NOT EXISTS signups_mig_seq")
+        # Start the new sequence after the current max id so inserts don't
+        # collide with migrated rows.
+        max_id = conn.execute("SELECT coalesce(max(id), 0) FROM signups").fetchone()[0]
+        start = max_id + 1
+
+        conn.execute(
+            f"CREATE SEQUENCE IF NOT EXISTS signups_mig_seq START WITH {start}"
+        )
         conn.execute("""
             CREATE TABLE signups_new (
                 id              BIGINT DEFAULT nextval('signups_mig_seq') PRIMARY KEY,

src/where_the_plow/migrations/007_fix_signups_sequence.py

@@ -0,0 +1,75 @@
+"""Fix signups auto-increment sequence.
+
+Migration 006 recreated the signups table with a new sequence
+(signups_mig_seq) that started at 1 instead of after the max existing id.
+This caused primary key conflicts on new inserts.
+
+Fix: recreate the table with a sequence seeded past max(id).
+Idempotent: only acts if the current sequence would produce a conflict.
+"""
+
+import duckdb
+
+
+def _find_signups_sequence(conn: duckdb.DuckDBPyConnection) -> str | None:
+    """Return the name of the sequence used by signups.id, if any."""
+    row = conn.execute(
+        "SELECT column_default FROM information_schema.columns "
+        "WHERE table_name='signups' AND column_name='id'"
+    ).fetchone()
+    if not row or not row[0]:
+        return None
+    # Default looks like: nextval('signups_mig_seq')
+    default = row[0]
+    if "nextval" in default and "'" in default:
+        return default.split("'")[1]
+    return None
+
+
+def upgrade(conn: duckdb.DuckDBPyConnection) -> None:
+    row = conn.execute("SELECT coalesce(max(id), 0) FROM signups").fetchone()
+    max_id = row[0] if row else 0
+
+    if max_id == 0:
+        # Empty table — nothing to fix.
+        return
+
+    seq_name = _find_signups_sequence(conn)
+    if not seq_name:
+        return
+
+    # Check if the sequence is already past max_id by peeking at nextval.
+    next_id = conn.execute(f"SELECT nextval('{seq_name}')").fetchone()[0]
+
+    if next_id > max_id:
+        # Sequence is already ahead — no fix needed.  But we consumed one
+        # value with the nextval above; that's harmless (just a gap).
+        return
+
+    # Need to recreate with a properly-seeded sequence.
+    start = max_id + 1
+    conn.execute(f"CREATE SEQUENCE signups_fix_seq START WITH {start}")
+    conn.execute("""
+        CREATE TABLE signups_fixed (
+            id              BIGINT DEFAULT nextval('signups_fix_seq') PRIMARY KEY,
+            timestamp       TIMESTAMPTZ NOT NULL DEFAULT now(),
+            name            VARCHAR NOT NULL DEFAULT '',
+            email           VARCHAR NOT NULL,
+            ip              VARCHAR,
+            user_agent      VARCHAR,
+            notify_plow     BOOLEAN NOT NULL DEFAULT FALSE,
+            notify_projects BOOLEAN NOT NULL DEFAULT FALSE,
+            notify_siliconharbour BOOLEAN NOT NULL DEFAULT FALSE,
+            note            VARCHAR
+        )
+    """)
+    conn.execute("""
+        INSERT INTO signups_fixed
+            (id, timestamp, name, email, ip, user_agent,
+             notify_plow, notify_projects, notify_siliconharbour, note)
+        SELECT id, timestamp, name, email, ip, user_agent,
+               notify_plow, notify_projects, notify_siliconharbour, note
+        FROM signups
+    """)
+    conn.execute("DROP TABLE signups")
+    conn.execute("ALTER TABLE signups_fixed RENAME TO signups")

tests/test_migrate.py

@@ -374,7 +374,7 @@ def test_002_migrates_prod_db(tmp_path):
     )
     run_migrations(conn, migrations_dir)
 
-    assert get_version(conn) == 6
+    assert get_version(conn) == 7
 
     # Vehicles should have source column with composite PK
     veh_cols = {
@@ -496,6 +496,6 @@ def test_already_migrated_db_gets_stamped(tmp_path):
     )
     run_migrations(conn, migrations_dir)
 
-    # Should be stamped at version 6 with no errors
-    assert get_version(conn) == 6
+    # Should be stamped at version 7 with no errors
+    assert get_version(conn) == 7
     conn.close()