nodejs如何取消与oracle的连接

我写的js代码是这样的
pp.get('/getOracle/queryForecastContents/*',function(req,res){//弹窗
var splitUrl=spiltUrl(req);
//var publishDate=ToCurrentTime(splitUrl);
var publishDate="2016/05/19 8:00:00";
var period=splitUrl[9];
var sql="SELECT AREAID,WINDDIRECTION,WINDSPEED,WAVEDIRECTION,WAVEHEIGHT FROM TBFORECASTCONTENTS WHERE PERIOD="+period+
"AND PUBLISHDATE="+toDate(publishDate);
oracledb.getConnection(
{
user:"NODE",
password:"admin",
connectString:"192.168.3.12/ORCL"
},
function(err,connection){
if(err) {
console.error(err.message);
return;
}
connection.execute(
//"SELECT * FROM TBWARNTIDE"
sql
,
function(err,result){
if(err){
console.error(err.message);
return;
}
console.log(result.rows);
res.send(result.rows);
});
connection.close();
});

});
我在前端测试了很多次之后,发现Oracle中的进程数到了顶峰,经常就取不到数据了。我关了服务器之后,马上进程数就下来了,我后来加了connection.close()之后,测试了几次,发现进程数还是增加了。求大神帮帮帮忙,这是咋回事啊?

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