adapter

type DBAdapter interface {
	// get current unique id for all shards by sequencer
	CurrentSequenceID(conn *sql.DB, tableName string) (int64, error)

	// get next unique id for all shards by sequencer
	NextSequenceID(conn *sql.DB, tableName string) (int64, error)

	// create database if not exists by database configuration file.
	ExecDDL(config *config.DatabaseConfig) error

	// open connection by database configuration file
	OpenConnection(config *config.DatabaseConfig, queryValues string) (*sql.DB, error)

	// create table for sequencer if not exists
	CreateSequencerTableIfNotExists(conn *sql.DB, tableName string) error

	// insert first row to sequencer if not exists
	InsertRowToSequencerIfNotExists(conn *sql.DB, tableName string) error
}