req is slice of struct or pointer struct.

JoinNamedColumnsValues foo=:foo,bar=:bar, for update set.

used for batch insert ( :group_id_1, :page_id_1, :fea_id_1, :entity_id_1, :feature0_1, :feature1_1, :extend_info_1 ), ( :group_id_2, :page_id_2, :fea_id_2, :entity_id_2, :feature0_2, :feature1_2, :extend_info_2 ) */.

JoinNamedColumnsValuesWithOperator "foo=:foo AND bar=:bar" , for where condition.

"foo=:foo AND bar=:bar".

"ORDER BY create_time DESC, id DESC".

pointer struct model for dest.

used for batch insert.

Default values for Mysql.

Default values for Mysql.

EmptyConfigOption does not alter the configuration.

EmptyDBUrlOption does not alter the DBuration.

A ConfigOption sets options.

A DBOption sets options.

ConfigOptionFunc wraps a function that modifies Client into an implementation of the ConfigOption interface.

DBOptionFunc wraps a function that modifies DB into an implementation of the DBOption interface.