语法:CREATE [索引类型] INDEX 索引名称ON 表名(列名) 创建索引实例: 聚簇索引 create clustered index index_name on table_name (cloumn_name); 非聚簇索引 create nonclustered index index_name on table_name (cloumn_name); 唯一索引 create unique index index_name on table_name(cloumn_name); 删…
面积表中数据错误,现将面积表中的sfmj字段的值改为居民信息表中匹配字段的值 update (select s.name name1,s2.name name2 from simple s,simple2 s2 where s.id=s2.id) v set v.name1=v.name2; 通用sql update (select A.sfmj mj1,B.sfmj mj2 from sf_jmmj_t A,sf_jmyh_t B where A.yhbh=B.yhbh) C set C.MJ…
text = 'The rain in Spain falls mainly in the plain.'first = Hash.new []second = Hash.new {|hash,key| hash[key] = []} text.split(/\W+/).each do |word| p "word: #{word}" p first[word[0, 1].downcase].object_id first[word[0, 1].downcase] << w…