i feeding my Data table from excel sheet upload,i face the problem when i look for a particular columns, ironically i don't know the position of column ,That can be anywhere or may be not present
so i cant Use indexing,when i go with column name then white spaces causing the problem
i assume the i know the index of Column but how can i handle the whitespaces
so far what i tried
Code:
if (ds.Tables[0].Columns[3].Caption.Replace(" ", "").Equals("XXXX"))
{
var ds = from r in ds.Tables[0].AsEnumerable() select new { Fname=r.Field<String>("XX XX") , Lname=r.Field<string>(" Yy YY Y ") };
ds.ToList();
}
Do i need to care About the case sensitiveness in Column Name ?
how can i find the Column index if it matched with a given String ?
You can find the column like:
DataColumn yourColumn = ds.Tables[0].Columns.Cast<DataColumn>()
.Where(r => r.Caption.Trim().Equals("XXXX",StringComparison.InvariantCultureIgnoreCase))
.FirstOrDefault();
Related
I'm struggling on passing the column value to a formula. I tried many different combinations but I only have it working when I hard code the column,
(tbl as table, col as list) =>
let
avg = List.Average(col),
sdev = List.StandardDeviation(col)
in
Table.AddColumn(tbl, "newcolname" , each ([column] - avg)/sdev)
I'd like to replace [column] by a variable. In fact, it's the column I use for the average and the standard deviation.
Please any help.
Thank you
This probably does what you want, called as x= fctn(Source,"ColumnA")
Does the calculations using and upon ColumnA from Source table
(tbl as table, col as text) =>
let
avg = List.Average(Table.Column(tbl,col)),
sdev = List.StandardDeviation(Table.Column(tbl,col))
in Table.AddColumn(tbl, "newcolname" , each (Record.Field(_, col) - avg)/sdev)
Potentially you want this. Does the average and std on the list provided (which can come from any table) and does the subsequent calculations on the named column in the table passed over
called as x = fctn(Source,"ColumnNameInSource",SomeSource[SomeColumn])
(tbl as table, cname as text, col as list) =>
let
avg = List.Average(col),
sdev = List.StandardDeviation(col)
in Table.AddColumn(tbl, "newcolname" , each (Record.Field(_, cname) - avg)/sdev)
New to PowerQuery and M-Code.
I have added a column with a calculation to get the max. Instead of using the hardcoded column name, I would like to use the position number of the column.
The current code is:
= Table.AddColumn(Source, "Maximum", each List.Max({[#"1-6-2021"], [#"1-5-2021"], [#"1-4-2021"]}), type number)
Instead of [#"1-6-2021"], I would like it to be column 3; for [#"1-5-2021"] column 4 etc.
How do I replace these columnnames with positions?
Many thanks for the help!
You can adjust the {x} part for the column # you want
0 is the first column, so this is max of columns 2/3/4
let Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
x= Table.AddColumn(Source, "Maximum", each List.Max({
Record.Field(_,Table.ColumnNames(Source){1}),
Record.Field(_,Table.ColumnNames(Source){2}),
Record.Field(_,Table.ColumnNames(Source){3})
}), type number)
in x
If you need to do a Max on a bunch of columns, below would, for example, do it for all columns except the first two, which are removed by the 2nd line
let Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
colToSum = List.RemoveFirstN(Table.ColumnNames(Source),2),
AddIndex = Table.AddIndexColumn(Source,"Index",0,1),
GetMax = Table.AddColumn(AddIndex, "Custom", each List.Max( Record.ToList( Table.SelectColumns(AddIndex,colToSum){[Index]}) ))
in GetMax
I am trying to invoke a function on an added column that will concatenate two columns. The catch is that I can't use the column name shorthand as I use dynamic parameters using strings to determine the column name.
Therefore the result is that I get a column as a List multiplied per row rather than the concatenated value for the specific row as intended
(func as text) =>
let
Source = Excel.CurrentWorkbook(){[Name="DataTBL"]}[Content],
\\This is the string extraction process for the parameter
funcTrig = Text.Start(func, 1),
columnA = "" & Text.BetweenDelimiters(func,"_","_") & "",
columnB = "" & Text.AfterDelimiter(func,"_",1) & "",
\\converting the string to column data
Convert2ColA = Table.Column(Source,columnA),
Convert2ColB = Table.Column(Source,columnB),
\\function to concatanate column A value at a specific row with column B value at the same row.
concat= StraightForward(Convert2ColA ,Convert2ColB)
in
concat
I have outlined with remarks the process and desired results, In the added picture I have pulled out the result of "Convert2ColA" what is the desired result will be 1999 in row one and so on.
After running the query below and hovering over "usersToWork" when debugging, I can view all of the properties of the single entry that I get returned to me in addition to the other tables that have relations to this value. What I need to display to the user is the "Lines.Id" (Lines being the table and Id being the column in the Lines table) value, however that value gets lost from the SelectMany() statements. Is there anyway to select that "Lines.Id" value to include in the final value that I get from all of my joins? In the code below, I commented out what I want but I can't place that there otherwise I get error on the first SelectMany statement saying 'int' does not contain a definition for 'Shifts' and no extension method 'Shifts' accepting a first argument of type 'int' could be found.'
Correct me if I'm wrong but SelectMany() selects all of the columns from what you want to join on. In this case, in the first SelectMany() I get only values from the "Shifts" table and in the second SelectMany() I get only values from the "Users" table. Why is this different from the SQL join? When joining in SQL you can get every column as you join them together, SelectMany() yields only the values of the second table that you are joining on. Is it even possible to get that value in the "Lines" table or will I have to do another query? Any help would be great.
int idEnteredByUser = 123;
var usersToWork = entityDataModel.Lines
//....NOT IN MY CODE NOW....
// .Select(line => line.Id)//THIS IS WHAT I NEED.
// .Select(line => line.Description, line.Id//OR THIS TO RETURN TWO VALUES IF POSSIBLE
//This is my current code, I need to include on of the select lines above.
.SelectMany(line => line.Shifts) //Join lines on shifts.
.Where(shift => shift.EndTime >= DateTime.Now) //Join restricted times.
.SelectMany(user => user.Users) //Join the restricted shift times on users.
.Where(user => user.UserId == idEnteredByUser ); //Only look for the specific user
This works much easier using LINQ query syntax.
I'm assuming that you made a typo in your posted code and that user is a property of shift.
var idEnteredByUser = 123;
var usersToWork =
from line in entityDataModel.Lines
from shift in line.Shifts
where shift.EndTime >= DateTime.Now
from user in shift.Users
where user.UserId == idEnteredByUser
select new
{
Description = line.Description,
Id = line.Id
};
I am trying to select some records using LINQ for Entities (EF4 Code First).
I have a table called Monitoring with a field called AnimalType which has values such as
"Lion,Tiger,Goat"
"Snake,Lion,Horse"
"Rattlesnake"
"Mountain Lion"
I want to pass in some values in a string array (animalValues) and have the rows returned from the Monitorings table where one or more values in the field AnimalType match the one or more values from the animalValues. The following code ALMOST works as I wanted but I've discovered a major flaw with the approach I've taken.
public IQueryable<Monitoring> GetMonitoringList(string[] animalValues)
{
var result = from m in db.Monitorings
where animalValues.Any(c => m.AnimalType.Contains(c))
select m;
return result;
}
To explain the problem, if I pass in animalValues = { "Lion", "Tiger" } I find that three rows are selected due to the fact that the 4th record "Mountain Lion" contains the word "Lion" which it regards as a match.
This isn't what I wanted to happen. I need "Lion" to only match "Lion" and not "Mountain Lion".
Another example is if I pass in "Snake" I get rows which include "Rattlesnake". I'm hoping somebody has a better bit of LINQ code that will allow for matches that match the exact comma delimited value and not just a part of it as in "Snake" matching "Rattlesnake".
This is a kind of hack that will do the work:
public IQueryable<Monitoring> GetMonitoringList(string[] animalValues)
{
var values = animalValues.Select(x => "," + x + ",");
var result = from m in db.Monitorings
where values.Any(c => ("," + m.AnimalType + ",").Contains(c))
select m;
return result;
}
This way, you will have
",Lion,Tiger,Goat,"
",Snake,Lion,Horse,"
",Rattlesnake,"
",Mountain Lion,"
And check for ",Lion," and "Mountain Lion" won't match.
It's dirty, I know.
Because the data in your field is comma delimited you really need to break those entries up individually. Since SQL doesn't really support a way to split strings, the option that I've come up with is to execute two queries.
The first query uses the code you started with to at least get you in the ballpark and minimize the amount of data you're retrieving. It converts it to a List<> to actually execute the query and bring the results into memory which will allow access to more extension methods like Split().
The second query uses the subset of data in memory and joins it with your database table to then pull out the exact matches:
public IQueryable<Monitoring> GetMonitoringList(string[] animalValues)
{
// execute a query that is greedy in its matches, but at least
// it's still only a subset of data. The ToList()
// brings the data into memory, so to speak
var subsetData = (from m in db.Monitorings
where animalValues.Any(c => m.AnimalType.Contains(c))
select m).ToList();
// given that subset of data in the List<>, join it against the DB again
// and get the exact matches this time
var result = from data in subsetData
join m in db.Monitorings on data.ID equals m.ID
where data.AnimalType.Split(',').Intersect(animalValues).Any ()
select m;
return result;
}