Insert 和Update的吗，Merge的语法如下：
View Code
1 MERGE INTO table_name alias1
2 USING (table|view|sub_query) alias2
3 ON (join condition)
4 WHEN MATCHED THEN
5 UPDATE table_name
6 SET col1 = col_val1,
7 col2 = col2_val
8 WHEN NOT MATCHED THEN
9 INSERT (column_list) VALUES (column_values);
上面的语法大家应该都容易懂吧，那我们按照以上的逻辑再写一次。
View Code
1 MERGE INTO T T1
2 USING (SELECT a,b FROM T WHERE t.a='1001') T2
3 ON ( T1.a=T2.a)
4 WHEN MATCHED THEN
5 UPDATE SET T1.b = 2
6 WHEN NOT MATCHED THEN
7 INSERT (a,b) VALUES('1001',2);
