仲宏偉（anmo）_javaBlog

語法：
         merge into table_name talbe_alias        //目標表
         using(table | view | sub_query) alias      //源表
         on(join condition)                                //合并數據的條件
         when matched then                             //如果條件成立則更新
         update set col1=col_val, col2=co2_val...
         when not matched then                       //如果條件不成立則插入
         insert (column_list) values(column_values);

 示例：
         //新建一張表
         create table test1(
          eid number(10),
          name varchar2(20),
          birth date,
          salary number(8,2)
         );

         //向表中插入數據
         insert into test1 values(1001,'張三','20-5月',2300);
         insert into test1 values(1002,'張三','01-6月',3000);

         //查詢表中的數據
         select * from test1;

          //新建第二張表，在表中不插入任何數據
          create table test2(
          eid number(10),
          name varchar2(20),
          birth date,
          salary number(8,2)
         );
 
         //查詢第二張表中的數據
         select * from test2;

 
         //使用merge進行數據合并
         merge into test2
         using test1
         on(test.eid = test2.eid)
         when matched then
          update set name = test1.name, birth = test1.birth, salary = test1.salary
         when not matched then
          insert(eid,name,birth,salary) values(test1.eid, test1.name, test1.birth, test1.salaru);

         select * from test2