ExecuteInTx runs fn inside tx which should already have begun.

ExecuteRetryable Retry functions that perform non-transactional database operations.

NewConfiguration creates a new Configuration struct.

Helper function for creating status errors that wrap underlying causes, usually DB errors.

AmbiguousCommitError represents an error that left a transaction in an ambiguous state: unclear if it committed or not.

Configuration 配置.

TxnRestartError represents an error when restarting a transaction.

ErrorCauser is the type implemented by an error that remembers its cause.

Scannable Interface to help utility functions accept either *sql.Row or *sql.Rows for scanning one row at a time.

Tx is used to permit clients to implement custom transaction logic.