下面语句:
select "name","class","score" from score_tbl where "score" > 80 group by 1,2
等价于:
select "name","class","score" from score_tbl where "score" > 80 group by "name","class"
含义:
"group by 1,2"的意思是说:按照select后面参数的第1列、第2列分组(从1开始计算,不含0)
下面语句:
select "name","class","score" from score_tbl where "score" > 80 group by 1,2
等价于:
select "name","class","score" from score_tbl where "score" > 80 group by "name","class"
含义:
"group by 1,2"的意思是说:按照select后面参数的第1列、第2列分组(从1开始计算,不含0)
本站转载的文章为个人学习借鉴使用,本站对版权不负任何法律责任。如果侵犯了您的隐私权益,请联系本站邮箱yoyou2525@163.com删除。