select count（*） from student和select count（id） from student之间的区别是什么？ -题库考试答案搜索网

select count（*） from student和select count（id） from student之间的区别是什么？

问答题

2022-01-04 17:36

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正确答案

select count（*）统计所有学生的记录个数，包括空记录。
select count（Id）统计所有学生的记录个数，不包括null记录。

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标签： Oracle认证综合练习 CMS专题 Oracle认证考试

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