Jsp中的多件查
我有三件 GuanLiNo Projectname PartNo ,
在的就是怎每件和件中的任意件合都能足查,
怎查句，的朋友多多指教，在下感激不。

<%
String GuanLiNo = request.getParameter( "GuanLiNo ");
String Projectname = request.getParameter( "Projectname ");
String PartNo = request.getParameter( "PartNo ");
session.getAttribute( "GuanLiNo ");
session.getAttribute( "Projectname ");
session.getAttribute( "PartNo ");
String sql;
sql= "select TOP 5* from PartPress where 1=1 ";
if(GuanLiNo!=null & Projectname!=null & PartNo!=null){
sql=sql+ "and Projectname = ' "+Projectname+
" 'or GuanLiNo= ' "+GuanLiNo+
" 'or PartNo= ' "+PartNo+ " ' ";
}
else if(GuanLiNo!=null & Projectname==null & PartNo==null){
sql=sql+ "and GuanLiNo= ' "+GuanLiNo+ " ' ";
}
else if(Projectname!=null & GuanLiNo==null & PartNo==null){
sql = sql + " and Projectname = ' "+Projectname+ " ' ";
}
ResultSet rs = jb.query(sql);
%>



[解决办法]
if(GuanLiNo!=null){
sql += " and GuanLiNo= ' "+GuanLiNo+ " ' ";

}
if(Projectname!=null){
sql += " and Projectname = ' "+Projectname+ " ' ";
}
if(PartNo!=null){
sql += " and PartNo= ' "+PartNo+ " ' ";
}

[解决办法]
public String getQueryStr(String str1,String str2,String str3){}
public String getQueryStr(String str1,String str2){}
public String getQueryStr(String str1){}
[解决办法]
最近比较烦的正确，自由在的虽然重载用得不错，也正确。
[解决办法]
<%
String GuanLiNo = request.getParameter( "GuanLiNo ");
String Projectname = request.getParameter( "Projectname ");
String PartNo = request.getParameter( "PartNo ");

session.getAttribute( "GuanLiNo ");
session.getAttribute( "Projectname ");
session.getAttribute( "PartNo ");

String sql = " ";

sql= "select TOP 5* from PartPress where 1=1 ";

if (GuanLiNo!= null & GuanLiNo.equals( " "))
sql += sql + "and Projectname = ' " + Projectname+ " ' ";

if (Projectname != null & Projectname.equals( " "))
sql += sql + "and Projectname = ' " + Projectname + " ' ";

if (PartNo != null & PartNo.equals( " "))
sql += sql + "and PartNo = ' " + PartNo + " ' ";

ResultSet rs = jb.query(sql);
%>
[解决办法]
上面的还有点小问题没有考虑清楚,在取条件的时候还要判断用户全部输入空格的时候.即下面代码:
String GuanLiNo = request.getParameter( "GuanLiNo ");
String Projectname = request.getParameter( "Projectname ");
String PartNo = request.getParameter( "PartNo ");

改为:
String GuanLiNo = (request.getParameter( "GuanLiNo ")).trim();
String Projectname = (request.getParameter( "Projectname ")).trim();
String PartNo = (request.getParameter( "PartNo ")).trim();