I have a section of LINQ that I need to compare - linq

var myArray = ["A3|001", "A2|002", "A1|003"];
string myValue = "A2";
var No_NewList = myArray.Where(r => r.Contains(myValue.ToUpper())).ToList();
But this is not the result I want
I want the result to be A2|002

How about:
var No_NewList = myArray
.Where(s => myValue.Equals(s.Split('|')[0]))
.FirstOrDefault();

Related

Invalid Date whilst using Moment() and Linq

I am having a problem where I have a 12 month period but beginning from zero index and its causing me to have an invalid date. Below is a picture of both my date array and chart js. Basically, because the months are zero indexed, they are out by one
and the below is the Linq query I am using, if anyone can help me fix this that would be great
var solicitor = _db.Records
.Where(j => j.Requestor == "Solicitor" && EF.Functions.DateDiffMonth(j.Request_Date, DateTime.Now) == 0 && EF.Functions.DateDiffMonth(j.Request_Date, DateTime.Now) <= 12)
.GroupBy(g => new { g.Request_Date.Value.Year, g.Request_Date.Value.Month }).OrderBy(d => d.Key.Year).ThenBy(d => d.Key.Month)
.Select(group => new
{
Dates = group.Key,
Count = group.Count()
});
var solicitorCount = solicitor.Select(n => n.Count).ToArray();
var date = solicitor.Select(n => n.Dates).ToArray();
and the code inside my chart js to format as moment
let newArr = []
for (let i = 0; i < simpleData[0].date.length; i++) {
var calDate = moment(simpleData[0].date[i]).format('MMM YYYY');
console.log(calDate)
newArr.push(calDate)
}
You can change your code like this:
let newArr = []
for (let i = 0; i < simpleData[0].date.length; i++) {
data[i].month -= 1;
var calDate = moment(simpleData[0].date[i]).format('MMM YYYY');
console.log(calDate)
newArr.push(calDate)
}
newArr result:

where does not contain array

my below query looks ok to me but im not sure why im getting errors.
The error is "the best overload for string.containts(string) has some invalid arguments". what am i missing here?
Thanks
string[] strHiddenESXi = {"Internal","Support","Archived"};
var tblvirtualservers = from d in db.tblVirtualServers.Include(t => t.ChangeLog).Include(t => t.ESXi)
where (!d.ESXi.ESXiName.Contains(strHiddenESXi)) && d.ESXiID != 20
string[] strHiddenESXi = {"Internal","Support","Archived"};
var tblvirtualservers = from d in db.tblVirtualServers.Include(t => t.ChangeLog)
.Include(t => t.ESXi)
where (!strHiddenESXi.Contains(d.ESXi.ESXiName)) && d.ESXiID != 20
You have to use Contains with strHiddenESXi that is an Array.
Can you try?
string[] strHiddenESXi = {"Internal","Support","Archived"};
var tblvirtualservers = from d in db.tblVirtualServers.Include(t => t.ChangeLog)
.Include(t => t.ESXi)
where (!strHiddenESXi.Any( a=> d.ESXi.ESXiName.Contains(a) )) && d.ESXiID != 20

How to iterate two arrays in CoffeeScript

I'm trying to rewrite example from classic book "JavaScript: The Good Parts" in CoffeeScript via list comprehensions:
var parse_url = /^(?:([A-Za-z]+):)?(\/{0,3})([0-9.\-A-Za-z]+)
(?::(\d+))?(?:\/([^?#]*))?(?:\?([^#]*))?(?:#(.*))?$/;
var url = “http://www.ora.com:80/goodparts?q#fragment”;
var result = parse_url.exec(url);
var names = ['url', 'scheme', 'slash', 'host', 'port', 'path', 'query', 'hash'];
var blanks = ' ';
var i;
for (i = 0; i < names.length; i += 1) {
document.writeln(names[i] + ':' +
blanks.substring(names[i].length), result[i]);
}
I can't get how to write loop and stuck with this code:
console.log "#{name}: " for name in names
I imagine you are trying to do something Like this
parse_url = /^(?:([A-Za-z]+):)?(\/{0,3})([0-9.\-A-Za-z]+)(?::(\d+))?(?:\/([^?#]*))?(?:\?([^#]*))?(?:#(.*))?$/
url = 'http://www.ora.com:80/goodparts?q#fragment'
result = parse_url.exec(url)
names = ['url', 'scheme', 'slash', 'host', 'port', 'path', 'query', 'hash']
alert "#{names[i]}: #{result[i]}" for i in [0..names.length-1]
In case someone comes here actually needing to iterate two arrays at the same time, this works:
for [course_event, remote_event] in zip(course.events, remote.events)
course_event.lessons = remote_event.lessons if event.lessons_need_updating
zip() is from here:
zip = () ->
lengthArray = (arr.length for arr in arguments)
length = Math.min(lengthArray...)
for i in [0...length]
arr[i] for arr in arguments

LINQ: Build a where clause at runtime to include ORs ( || )?

I need to build a where clause at runtime but I need to do an OR with the where clause. Is this possible?
Here is my code. Basically "filter" is a enum Bitwise, son hence filter could be equal to more than 1 of the following. Hence I need to build up the where clause.
If I execute the WHEREs separately then imagine if I do the Untested first, and it returns 0 records that means I can't execute a where on the Tested because its now 0 records.
I will put some pseudo-code below:
string myWhere = "";
if ((filter & Filters.Tested) == Filters.Tested)
{
if (myWhere != "" ) myWhere =myWhere + "||";
myWhere = myWhere " Status == "Tested";
}
if ((filter & Filters.Untested) == Filters.Untested)
{
if (myWhere != "" ) myWhere =myWhere + "||";
myWhere = myWhere " Status == "Untested";
}
if ((filter & Filters.Failed) == Filters.Failed)
{
if (myWhere != "" ) myWhere =myWhere + "||";
myWhere = myWhere " Status == "Failed";
}
// dataApplications = a List of items that include Tested,Failed and Untested.
// dataApplication.Where ( myWhere) --- Confused here!
Is this possible?
I don't want to include lots of "IFs" because there are lots of combinations i.e. no filter, filter= tested Only, filter = Untested and Tested ... and lots more.
If you have this:
IEnumerable<MyType> res = from p in myquery select p;
You can define a
var conditions = new List<Func<MyType, bool>>();
conditions.Add(p => p.PropertyOne == 1);
conditions.Add(p => p.PropertyTwo == 2);
res = res.Where(p => conditions.Any(q => q(p)));
And now the trick to make Lists of Funcs of anonymous objects (and you can easily change it to "extract" the type of anonymous objects)
static List<Func<T, bool>> MakeList<T>(IEnumerable<T> elements)
{
return new List<Func<T, bool>>();
}
You call it by passing the result of a LINQ query. So
var res = from p in elements select new { Id = p.Id, Val = p.Value };
var conditions = MakeList(res);
var statusTexts = new List<string>(); // Add desired status texts
dataApplication.Where(item =>
statusTexts.Any(status => item.Status == status))
Use HashSet<> for statuses, then .Contains will be O(1) instead of usual O(n) for List<>:
var statuses = new HashSet<string>() {"a", "b", "c"};
var list = new[] {
new { Id = 1, status = "a"},
new { Id = 2, status = "b"},
new { Id = 3, status = "z"}
};
var filtered = list.Where(l => statuses.Contains(s => l.status == s));

using if else with LINQ Where

I want to generate dynamic query to check manage the where clause with number of parameters available...if some parameter is null i don't want to include it in the where clause
var test = from p in _db.test
where if(str1 != null){p.test == str} else i dnt wanna check p.test
I have around 14 parameters for the where clause
need help,
thanks
You can do it in steps:
// set up the "main query"
var test = from p in _db.test select _db.test;
// if str1 is not null, add a where-condition
if(str1 != null)
{
test = test.Where(p => p.test == str);
}
In addition to #Fredrik's answer, you can also use the short-circuit rules when evaluating boolean expressions like so:
var test = from p in _db.test
where str1 == null || p.test == str1;
Edit If you have lots of strings to test, (str1, str2, etc...) then you can use the following, which will be translated to an SQL IN clause:
var strings = new List<string>();
if (str1 != null) strings.Add(str1);
if (str2 != null) strings.Add(str2);
if (str3 != null) strings.Add(str3);
...
var test = from p in _db.test
where strings.Contains(p.test);
It's even easier if your strings are already in a collection (which, if you've got 14 of them, I assume they would be...)
Consider param1 and param2 are the parameters. Your query should be as under:
string param1 = "Value1";
string param2 = "Value2";
var q = from bal in context.FxBalanceDetails
where (string.IsNullOrEmpty(param1) || bal.Column1 == param1)
&& (string.IsNullOrEmpty(param2) || bal.Column2 == param2)
select bal;
This will ensure that the where clause gets applied for the particular parameter only when it is not null.
var test =
from p in _db.test
where p.str1 != null ? p.str1 : ""
select p;
Do you check the strings against the same Field of the entity?
If so you can write something like:
var strings = new[] { "foo", "bar", "ok", "", null };
var query = dataContext.YourTable.AsQueryable();
query = strings.Where(s => !string.IsNullOrEmpty(s))
.ToList()
.Aggregate(query, (q, s) => q.Where(e => e.YourField == s));
EDIT:
The previous solution is overcomplicated:
var strings = new[] { "foo", "bar", "ok", "", null }.Where(s => !string.IsNullOrEmpty(s))
.ToList();
var query = dataContext.YourTable.Where(e => strings.Contains(e.YourField));

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