aq.executeQuery:[MICROSOFT][ODBC Microsoft Acess Driver]INSERT INTO 语句的语法错误

uploader\file_name\date已初始化
写入ACCESS的JSP语句:
String sql="insert into upload (uploader,file_name,date) values('"+uploader+"','"+file_name+"','"+date+"')";
ResultSet rs=insert.executeUpdate(sql);

页面没有提示错误,只是到数据库中查对时,发现并没有写入任何记录.
TOMCAT编译器提示:aq.executeQuery:[MICROSOFT][ODBC Microsoft Acess Driver]INSERT INTO 语句的语法错误.请指教.



附读写数据库的BEAN文件:
public class access_dbconnect{
String sDBDriver = "sun.jdbc.odbc.JdbcOdbcDriver";
String sConnStr="jdbc:odbc:user";

Connection conn = null;
ResultSet rs= null;

public access_dbconnect()
{
try{
Class.forName(sDBDriver);
}
catch(java.lang.ClassNotFoundException e)
{
System.err.println("Class access_dbconnect not found"+e.getMessage());

}
}
public ResultSet executeQuery(String sql)
{
rs=null;
try{
conn=DriverManager.getConnection(sConnStr);
Statement stmt=conn.createStatement();
rs=stmt.executeQuery(sql);
}
catch(SQLException ex)
{
System.err.println("aq.executeQuery:"+ex.getMessage());
}

return rs;
}
public ResultSet executeUpdate(String sql)
{
rs=null;
try{
conn=DriverManager.getConnection(sConnStr);
Statement stmt=conn.createStatement();
rs=stmt.executeQuery(sql);
}
catch(SQLException ex)
{
System.err.println("aq.executeQuery:"+ex.getMessage());
}

return rs;
}
}