README
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MySQL sequencing
Default: original transient transaction
PresetIDWithTransientTransaction is the default, preserving original Datly and
SQLX selection. transient.go, handler.go and udf.go remain byte-for-byte
unchanged from 24e180f. The generic exact-value API invokes the original
NextSequence path and adapts its returned range without changing its SQL,
transaction, session, locking, cleanup or retry semantics.
No allocator table is needed. Source AUTO_INCREMENT is advanced by transient source INSERTs in a separate transaction which SQLX rolls back. A caller's transaction is not completed by this operation.
The mechanism needs a spare connection when a caller already holds a transaction, and may wait on source locks held by that caller. Source defaults/triggers and applicable constraints execute. Transactional rows roll back; nontransactional or external effects need not. Original FK toggling/restoration, advisory lock names, timeout/retries and the last-bound-argument identity assumption remain unchanged. These limits are documented and tested, not repaired by this patch. go-sql-driver/mysql can invalidate the caller connection/transaction when a blocked allocation context is cancelled. SQLX does not commit or roll back that caller transaction, but it cannot promise the driver-cancelled handle remains usable. Cancellation tests therefore require an error, no committed source rows and no silent allocator-table fallback; noncancelled caller ownership has a separate positive test.
Explicit reservation option
The native InnoDB table allocator is opt-in. Provision with
Store.Install(ctx, db) outside writer transactions, then pass
dialect.PresetIDWithReservation to the insert/sequence service. It uses
sqlx_allocator.sequence_reservations, caller-transaction row locking and no
transient source INSERTs. It can operate with a single caller connection.
Runtime credentials need SELECT/INSERT/UPDATE on native metadata and source access. It honors native field mapping, increment/offset and integer bounds. Rollback can release its reservation. Unmanaged source AUTO_INCREMENT inserts do not see outstanding metadata reservations; do not mix generators. The default never switches to this optional owner when the transient mechanism fails.
Documentation
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Index ¶
Constants ¶
const MaxSeqValue = 9223372036854775807
MaxSeqValue represents default maximum sequence value
Variables ¶
This section is empty.
Functions ¶
func UpdateMySQLSequence ¶
func UpdateMySQLSequence(ctx context.Context, db *sql.DB, target interface{}, iopts ...interface{}) (doNext bool, err error)
UpdateMySQLSequence updates for all passed sink.Sequences theirs Value or StartValue getting autoincrement metadata by: SHOW CREATE TABLE ..., @@SESSION.auto_increment_increment, @@SESSION.auto_increment_offset
Warning! Until we don't use autoincrement in the table (by insert at least one row with 0-value id), "show create table" and "information_schema.tables" show wrong autoincrement value if @@SESSION.auto_increment_increment > 1
Types ¶
type ReservationLock ¶ added in v0.26.1
type ReservationLock struct{}
ReservationLock defers row locking until native column identity is known. The InnoDB reservation uses a current locking read, including under RR.
func (*ReservationLock) CanUse ¶ added in v0.26.1
func (*ReservationLock) CanUse(...interface{}) bool
type ReservationMetadata ¶ added in v0.26.1
type ReservationMetadata struct{}
ReservationMetadata validates the physical AUTO_INCREMENT column rather than inferring an allocator from a product name or an authored primary-key tag.
func (*ReservationMetadata) CanUse ¶ added in v0.26.1
func (*ReservationMetadata) CanUse(opts ...interface{}) bool
type ReservationRange ¶ added in v0.26.1
type ReservationRange struct{}
func (*ReservationRange) CanUse ¶ added in v0.26.1
func (*ReservationRange) CanUse(opts ...interface{}) bool
type Store ¶ added in v0.26.1
type Store struct{}
Store provisions native allocator metadata outside application transactions. MySQL DDL implicitly commits: allocation never invokes Install, creates source objects, modifies source schema, or borrows a second caller connection.
type StrategyError ¶ added in v0.26.1
type StrategyError struct{}
StrategyError prevents a placeholder query from pretending to allocate IDs.
func (*StrategyError) CanUse ¶ added in v0.26.1
func (*StrategyError) CanUse(...interface{}) bool
type Transient ¶
type Transient struct{}
Transient represents struct used to setting new autoincrement value using insert inside new transaction finished by rollback
type Udf ¶
type Udf struct{}
Udf represents struct used to setting new autoincrement value using user defined stored procedure in db and internal autoincrement value handling
func (*Udf) Handle ¶
func (n *Udf) Handle(ctx context.Context, db *sql.DB, target interface{}, iopts ...interface{}) (doNext bool, err error)
Handle sets new autoincrement value by executing user defined stored procedure and using internal autoincrement value handling
all this handler requires more testing (especially with transactions)
Source Files