oracle merge语句
merge into 表名 a using
(select ? as 字段1,? as 字段2,….. from dual)
b on (a.字段1=b.字段1 and ….)（判断的条件）
when matched then
update set 字段1=字段1,……
when not matched then
insert (字段1,字段2,…) values(b.字段1,b.字段2,….)
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例子如下：表名：TR_RUNNING_MONITOR ；字段名：LAST_TASK_ROWID，LAST_CRAWL_DATE，
START_TIME，DOC_COUNT，HIT_COUNT，OP_TYPE，DOC_TYPE
merge into TR_RUNNING_MONITOR a using
(select ? as LAST_TASK_ROWID,? as LAST_CRAWL_DATE,? as START_TIME,? as DOC_COUNT,
? as HIT_COUNT,? as OP_TYPE,? as DOC_TYPE,sysdate as UPDATE_TIME from dual) b on (a.OP_TYPE=b.OP_TYPE and a.DOC_TYPE=b.DOC_TYPE) when matched then
update set DOC_COUNT=DOC_COUNT,HIT_COUNT=HIT_COUNT,START_TIME=START_TIME,UPDATE_TIME
=UPDATE_TIME,
LAST_CRAWL_DATE=LAST_CRAWL_DATE,LAST_TASK_ROWID=LAST_TASK_ROWID when not matched then
insert (OP_TYPE,DOC_TYPE,DOC_COUNT,HIT_COUNT,START_TIME,UPDATE_TIME,LAST_CRAWL_DATE,
LAST_TASK_ROWID) oracle账号
values(b.OP_TYPE,b.DOC_TYPE,b.DOC_COUNT,b.HIT_COUNT,b.START_TIME,b.UPDATE_TIME,
b.LAST_CRAWL_DATE,b.LAST_TASK_ROWID)
说明：用OP_TYPE和DOC_TYPE跟表TR_RUNNING_MONITOR中的这两个字段比较，相同时进行update，
不同时进行insert