Mutations

Compiled mutations are schema-owned write pipelines used by the compiler and by CompiledCommand lowering. They are declared in .conjure files and compiled ahead of time.

For gameplay state transitions, prefer Compiled Commands. Commands add typed errors, event payloads, effect manifests, and direct subcommand composition on top of mutation primitives.

Update

mutation AddExperience(playerId: int, amount: int) {
    update Players
    | filter Id == @playerId
    | set Experience = Experience + @amount
}

Insert

mutation CreatePlayer(id: int, name: string) {
    insert Players
    | values (Id = @id, Name = @name, Level = 1, Experience = 0)
}

Upsert

mutation GrantItem(playerId: int, itemId: int, amount: int) {
    upsert InventorySlots
    | filter PlayerId == @playerId and ItemId == @itemId
    | set Amount = Amount + @amount
}

Note: This is the upsert-mutation form of GrantItem. It is distinct from the GrantItem command, which wraps this primitive with typed errors, key/returning contracts, and an event payload.

Delete

mutation RemoveExpiredReward(playerId: int, rewardId: int) {
    delete RewardClaims
    | filter PlayerId == @playerId
    | filter RewardId == @rewardId
}

Bulk mutation forms remain storage-level primitives. Command bodies use stricter single-row write statements with explicit key, require, and returning ... into contracts.

Atomicity

External operation dispatch owns transaction boundaries. Generated command ExecuteCore methods do not open nested transactions. Storage-level mutations remain atomic when invoked through their owning generated wrapper.