作用：merge into 解决用B表跟新A表数据，如果A表中没有，则把B表的数据插入A表；当处理大数据量是，该方法的效率很高。
语法：
MERGE INTO [your table-name] [rename your table here]
USING ( [write your query here] )[rename your query-sql and using just like a table]
ON ([conditional expression here] AND [...]...)
WHEN MATHED THEN [here you can execute some update sql or something else ]
WHEN NOT MATHED THEN [execute something else here ! ]
实例：
Sql代码
View Code
1 merge into data_complaint_day_test2 s 2 using (select seq_id, 3 handle_date, 4 V_COMPLAINT_TYPE, 5 STATISTICS_LEVEL, 6 feedback_date, 7 node, 8 done_date, 9 finished_date, 10 handle_workgroup, 11 v_dept_name, 12 v_area, 13 n_sh_complaint 14 from data_complaint_day_test t 15 where t.rowid in (select max(b.rowid) from data_complaint_day_test b group by (b.seq_id))) t 16 on (s.seq_id = t.seq_id ) 17 when matched then 18 update set 19 s.handle_date = t.handle_date, 20 s.service_req_type = t.v_complaint_type, 21 s.user_level = t.STATISTICS_LEVEL, 22 s.feedback_date = t.feedback_date, 23 s.node = t.node, 24 s.done_date = t.done_date, 25 s.finished_date = t.finished_date, 26 s.handle_workgroup = t.handle_workgroup, 27 s.v_dept_name = t.v_dept_name, 28 s.v_area = t.v_area 29 when not matched then 30 insert ( s.seq_id, 31 s.handle_date, 32 s.service_req_type, 33 s.user_level, 34 s.feedback_date, 35 s.node, 36 s.done_date, 37 s.finished_date, 38 s.handle_workgroup, 39 s.v_dept_name, 40 s.v_area, 41 s.n_sh_complaint) 42 values ( t.seq_id, 43 t.handle_date, 44 t.V_COMPLAINT_TYPE, 45 t.STATISTICS_LEVEL, 46 t.feedback_date, 47 t.node, 48 t.done_date, 49 t.finished_date, 50 t.handle_workgroup, 51 t.v_dept_name, 52 t.v_area, 53 t.n_sh_complaint);
where t.rowid in (select max(b.rowid) from data_complaint_day_test b group by (b.seq_id))
因为在data_complaint_day_test 表中会出现seq_id字段相同的记录，这里只取一条
上面代码是一个存储过程的部分代码。
测试效果：10万条数据，15s完成