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11.png统计数据sql语句SELECT name,count(*) FROM test GROUP BY name;数据结果12.png统计数据后排序SELECT name,count(*) as count FROM test GROUP BY name ORDER BY -name;13.png统计数据后筛选大于2的数据SELECT name,count(*) as co...

特殊字符 替代符号（红色基本为常用的） & & < < > > " " ' '小于等于 a<=b a <= ...