Develop Reference

Unable to change foreach to LINQ syntax

I am trying unsuccessfully to change the following loop to a LINQ expression:
int index = 0;
IList<IWebElement> divNota = new List<IWebElement>();
foreach (IWebElement element in tablaNotas)
{
divNota.Add(element.FindElement(By.Id("accion-1-celda-0-" + index + "-0")));
index++;
}
I tried using
IList <IWebElement> divNota = tablaNotas.Select(element => element.FindElement(By.Id("accion-1-celda-0-"+ tablaNotas.IndexOf(element) + "-0"))).ToList();
But tablaNotas.IndexOf(element)always returns -1, meaning the element was not found inside tablaNotas.
The string "accion-1-celda-0-"+ tablaNotas.IndexOf(element) + "-0" is meant to change to
"accion-1-celda-0-"+ 1 + "-0"
"accion-1-celda-0-"+ 2 + "-0"
"accion-1-celda-0-"+ 3 + "-0"
...
"accion-1-celda-0-"+ n + "-0"
In accordance to element's index
Any help is appreciated

In Linq some reserved word like Where, FirstOrDefault create a condition for your query and the Select reserved word can create your object that you want the Select method applies a method to elements. It is an elegant way to modify the elements in a collection such as an array. This method receives as a parameter an anonymous function—typically specified as a lambda expression.
Example: Let's look at a program where the Select extension method is applied to a string array. A local variable of array type is allocated and three string literals are used. We use Select on this array reference.
The basic method are here:
public static System.Collections.Generic.IEnumerable<TResult> Select<TSource,TResult> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,int,TResult> selector);
Now! for this issue that you searched for that you can use of this code:
var divNotaResult = list
.Select((data, index) => data.FindElement(By.Id("accion-1-celda-0-" + index + "-0")))
.ToList();
In Select method do like foreach we have tow object in function data and index.
The data have each data in loop, and the index have count of loop.

var result = tableNotas
.Select((element, index) => element.FindElement(By.Id("accion-1-celda-0-" + index + "-0")))
.ToList();

Use this:
var divNota =
tablaNotas.Select((element, index) =>
element.FindElement(By.Id($"accion-1-celda-0-{index}-0")))
.ToList();

How to fix 'No property or field exists in type' error?

I got this error when trying to sort any columns that are not in the Order table, if I use OrderBy("Customer.CompanyName" + " " + sortDir) the error will gone but all the columns will become unable to sort. The OrderBy method used below come from here.
What is the cause of the problem ?
public ActionResult WebGrid(int page = 1, int rowsPerPage = 10, string sortCol = "OrderID", string sortDir = "ASC")
{
List<Order> res;
using (var nwd = new NorthwindEntities())
{
var _res = nwd.Orders
.OrderBy(sortCol + " " + sortDir)
.Select(o => new Order
{
OrderID = o.OrderID,
OrderDate = o.OrderDate,
CompanyName = o.Customer.CompanyName,
FirstName = o.Employee.FirstName,
//......
//......
//......
});

The class you provided the link to is marked as internal and it can't be used outside the assembly it was defined in, so you can't use it in your code.
This API supports the product infrastructure and is not intended to be
used directly from your code. Provides functionality to create new
classes from values in a LinqDataSource control.
So What you're actually trying to use is OrderBy inside Queryable class which is part of System.Linq which can be used as following:
.OrderBy(x=> x.sortCol + " " + x.sortDir)
If you're trying to order by two columns, then you can use:
.OrderBy(x=> x.sortCol).ThenBy(x=> x.sortDir)
If you want to dynamically specify the OrderBy expression, you can either do a switch statement for each possible parameter, or follow this SO Answer to build a dynamic Expression Tree.

Using dynamic type in LINQ queries

I'm using LINQ for querying the database. I'm using dynamic keyword in queries. I don't know this dynamic mechanism in depth, so I don't understand what's going on.
The situation follows. The following section of code:
var qGroup = qLocalOrd.GroupBy("new(...)", "it");
var qGroupCast = (qGroup as IQueryable<IGrouping<dynamic,dynamic>>).AsEnumerable();
var qAgg = from ordg in qGroupCast
select new {
ordg.Key,
Agg = (ordg.Key.OsID + " " + ordg.Key.NameOs + "\n" +
(ordg as IEnumerable<dynamic>).Aggregate("Составные части:\n", ...).Trim('\n') + ...)
};
Works just fine. But when I'm adding this to the end:
var qPlain = qAgg.Cast<dynamic>().AsQueryable().Select("new(Key.SubSchet, Key.NameSubSchet, ...)");
qPlain.Dump();
I'm receiving an error like "No field "Key" exists in type "Object"". It's the same if I use
(qAgg as IEnumerable<dynamic>)
So at this point dynamic treatment of qAgg elements is broken somewhy.
Why does this happen and how to make this thing work?

Procedurally create a dynamic object for Dapper

I've seen many posts about creating ExpandoObject objects and such, but it does not work in my case. I need to create an object like
var someObj = new {
term1 = "someValue",
term2 = "other",
...
};
Basically, we are using Dapper and we need to create a query dynamically, where the WHERE clause is fabricated from a given array of arguments. We are not generalizing queries! It's a single method receiving a variable number of arguments and we need to check OR each value on a single column.
Right now, the only viable solution is to revert and directly use System.Data.SqlClient.SqlConnection, or is there any way to make this work?
Update:
This is what most likely should work, but doesn't :
string inWhere = null;
dynamic inTerms = new ExpandoObject();
IDictionary<string, object> inTermsDict = inTerms;
if (!(string.IsNullOrEmpty(filter.Term) || string.IsNullOrWhiteSpace(filter.Term))) {
inWhere = "(" + string.Join(" OR ", filter.Terms.Select((t, i) => "{0} LIKE #p" + i)) + ")";
int termIndex = 0;
foreach (string term in filter.Terms) {
inTermsDict.Add("p" + (termIndex++), term);
}
}
// ...
var rows = db.Query("SELECT * FROM {table} WHERE {baseCondition}" +
(string.IsNullOrEmpty(inWhere) ? "" : string.Format(" AND " + inWhere, "columnName")),
inTerms as object);

Just to answer my own question, as we found the proper solution earlier today.
Simply put, we found the IDynamicParameters And this class simply solves everything, acting as a Dictionary.
var inTerms = new Dapper.DynamicParameters();
inTerms.Add("#p" + (termIndex++), somveValue);
Everyone's happy!

Sharepoint list Dynamic Linq query

I need to query a list in SharePoint where the columns may be added in the future.
For instance at the moment I have the following columns
Name, Job, interests, address
I want to be able to query this string dynamically using a parameter from the browser so if columns are added in the future I don’t have to change the code but just the parameter.
The address may look like this www.contoso.com/sites/mypage.aspx?property=Interests
And the code something on the line of this:
var SiteParameter = Request.QueryString["property"];
var ItemsFromList = from item in ListItems where item[try to put the parameter in here] select item;
I use SPmetal to get the list details, so if I press item. Visual Studio2010 will return the columns within the list.

This may be easier without SPMetal.
var qy = new SPQuery();
qy.Query =
"<Where><Eq>" +
"<FieldRef Name=`" + siteParameter + "'/>" +
// You may have to worry about the type of the field here, too.
"<Value Type='Text'>" + desiredValue + "</Value>" +
"</Eq></Where>";
var itemCollection = myList.GetItems(qy);