oracle – 如何使用另一个表的列值更新一个表列值?
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Update rows in one table with data from another table based on one column in each being equal????????????????????????????????????5个
现在我想用where条件Student.uniquename = Employee.uniquename和Student.Homecountry = Employee.Homecountry下的Employee表的资格列值更新Student表的department列. 请帮我写一下更新声明. 解决方法这种查询称为相关子查询.根据您的要求,查询如下….update students s set s.department = ( select e.qualification from employee e where s.uniquename = e.uniquename and s.Homecountry = e.Homecountry ); 根据您的回复更新此帖子. 再次,继续,始终发布创建表并插入语句(和预期结果)来重现您的案例.如果您没有看到预期的结果,或者在执行查询时看到错误,请发布确切的消息,而不是仅仅说“不工作”.这是我的sqlplus会话的结果. —创建表和插入语句 create table student( name varchar2(20),age number,department varchar2(3),HomeCountry varchar2(10) ); Table created. create table employee5( name varchar2(20),exp number,qualification varchar2(3),homecountry varchar2(10) ); Table created. insert into student values ('Mohan',25,'EEE','India'); insert into student values ('Raja',27,'India'); insert into student values ('Ahamed',26,'ECE','UK'); insert into student values ('Gokul','IT','USA'); commit; insert into employee5 values ('Mohan','India'); insert into employee5 values ('Raja',24,'India'); insert into employee5 values ('Palani','USA'); insert into employee5 values ('Sathesh',29,'CSE','CANADA'); insert into employee5 values ('Ahamed',28,'UK'); insert into employee5 values ('Gokul','USA'); commit; 在更新数据之前…… SQL> select * from student; NAME AGE DEP HOMECOUNTR -------------------- ---------- --- ---------- Mohan 25 EEE India Raja 27 EEE India Ahamed 26 ECE UK Gokul 25 IT USA SQL> select * from employee5; NAME EXP QUA HOMECOUNTR -------------------- ---------- --- ---------- Mohan 25 ECE India Raja 24 IT India Palani 26 ECE USA Sathesh 29 CSE CANADA Ahamed 28 ECE UK Gokul 29 EEE USA 更新声明和结果 1 update student s set s.age = 2 ( select e.exp 3 from employee5 e 4 where e.name = s.name 5 and e.homecountry = s.homecountry 6* ) SQL> / 4 rows updated. SQL> select * from student; NAME AGE DEP HOMECOUNTR -------------------- ---------- --- ---------- Mohan 25 EEE India Raja 24 EEE India Ahamed 28 ECE UK Gokul 29 IT USA SQL> commit; Commit complete. (编辑:晋中站长网) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |