select sum(amount),sum(card_number) from sy_user inner join sy_admin on sy_user.customer_id=sy_admin.admin_id inner join sy_user_charge_log on sy_user.username=sy_user_charge_log.username where sta...
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什么是boolean类型,根据官方文档的描述:
boolean: The boolean data type has only two possible values: true and false. Use this data type for simple flags that tr...