摘要:
1、有唯一列,通过唯一列最大或最小方式删除重复记录 1 delete from zczjDataTemp 2 where cdnum in( select cdnum from zczjDataTemp group by cdnum having count(cdnum ) > 1) and 3 I 阅读全文
摘要:
linq 左连接写法 ,注意:这里主要第二个集合有可能为空。需要判断 1 2 var leftJoinSql = from student in Student 3 join book in Book on student.ID equals book.StudentID into temp 4 f 阅读全文