SQL guidelines

Adding SQL updates

cd data/sql/updates/pending_db_world/ (or pending_db_auth / pending_db_characters).
./create_sql.sh generates an empty rev_<timestamp>.sql to write into.
Conventions (linted): every INSERT preceded by a matching DELETE (idempotency); no double semicolons; no multiple blank lines; InnoDB engine.

Run the linter before claiming a change is done: python apps/codestyle/codestyle-sql.py (compares to origin/master).

smart_scripts edits always rewrite the full block — DELETE + INSERT of every row for the (entryorguid, source_type) pair, with the DELETE matching both columns — never a partial UPDATE, not even for a comment-only fix.
creature_immunities: negative ids are curated shared sets — reference them via creature_template.CreatureImmunitiesId, never edit them or allocate new ones. Positive ids are single-creature sets — reuse an existing set only on an exact match; to extend a creature's immunities, insert a superset under a new id and point the creature's CreatureImmunitiesId at it.

acore_auth — accounts, realm list, IP/account bans, session keys. Shared across all realms.
acore_characters — per-character state: characters, inventory, in-progress quests, mail, guilds, arena teams, achievements. One per realm.
acore_world — static game content: creature/gameobject/item/quest templates, spawn lists, loot tables, SmartAI scripts, gossip, conditions. Read-mostly; rebuilt from SQL.