问一个正则表达式的问题

Question

搜索就不用了，只要能给我替换就行了，我要把他用到mysql语句的update语句中去

Answer 1

<script>
function aa(idNo,nameNo,parentId)
{
this.idNo = idNo;
this.nameNo=nameNo;
this.parentId = parentId;
this.addItem = addItem;
}
var s = new Array();
function addItem(idNo,nameNo,parentId){
s.length = s.length+1;}
s[0] = new aa("1","名字1","0");
s[1] = new aa("2","名字2","1");
s[2] = new aa("3","名字3","1");
s[3] = new aa("4","名字4","2");
s[4] = new aa("5","名字5","5,2,1");
s[5] = new aa("6","名字7","1,2,1");
for(var i = 0;i<s.length;i++)
{
if(/5,2,1/.test(s[i].parentId))
{
alert("idNo="+s[i].idNo+ "  parentId=" + s[i].parentId);
s[i].parentId=s[i].parentId.replace(/5,2,1/,"3,1");
alert("s[i].parentId="+s[i].parentId)
}
}
</script>

Answer 2

alert("8,5,2,1".replace(/5,2,1/g,"3,1"));

Answer 3

var str="1/名字1/0;2/名字2/1;3/名字3/1;4/名字4/1;5/名字5/2,1;6/名字6/2,1;7/名字7/5,2,1;8/名字8/5,2,1;9/名字9/8,5,2,1;"
var s="5,2,1";
var reg = new RegExp("(\\d)/[^/;]+/[\\d+,]*("+s+")[^;]*","g");
var a=str.match(reg);
for (var i=0;i<a.length;i++){
a[i] = a[i].replace(reg,"$1");
}
var result=a.join();
alert(result)