I have a form with a list box The code loops through a Tables' row and gives me only one of each of the catergories. If more than one of a perticular item exist it only displays one. i would like to use Select Distinct instead just because it would cut down on the time it would take to read the Rows items and still give me the same results I just am not sure how to write it.
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Office 2010; Windows7; Visual Studio Basic 2008 (VB.Net)
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The following strSQL string is not working as expected when run in VB.Net Interop to Access: (NOTE: The line-feeds " _" are used below are for reading only - are not in actual code line)
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I am looking to select all the tables from a microsoft access database. I just need the SQL statement i think, i can connect to the database that is needed.
View 4 RepliesI can't quite figure out why this Linq Statement isn't working as i would expect:
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I would assume that this would create a new collection of anonymous types, that would be distinct. Instead it creates a collection the size of the "ThisParentCollection" with duplicate "MyAnonymousType" in it (duplicate id's).
I have a problem running a simple query: "select distinct payee from table". This query is set up in the dataset and is called GetAllPayee.My code goes something like:
Dim dtSources as new Datatable
dtSources =
Me.TblExpenseRecordsTableAdapter.GetAllPayee
Upon running I get the error:Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.The problem is, I haven't set ANY constraints on either the new datatable, or the dataset table (tblExpenseRecords). i.e. there is no primary key etc.
Can someone please help me out with this problem?I have no problems running the query through the wizard where I can view the results successfully.
Is it possible to select distinct in the rowfilter method?
I have something like:
VB
'Create a data view so we can get each items name
Dim dvwItemNames As New DataView(dtlItems)
dvwItemNames.RowFilter() = "SELECT DISTINCT Name"
This gives me a syntax error exception. I tried just "Distinct Name" but this had the same result. "Name" is the column name. I would rather do it this way then looping through the entire table and putting the name in an array list or something.
I have a single columned datatable inside a single tabled dataset.I just want to convert this dataset to distinct rows. Here is my code, it gives compile error '.' expected.
Dim query = _
From email In ds.Tables(0) _
Select email.Field<string>("Email").Distinct()
EDIT: I changed to (Of String) and it works... BUT NOW 'query' is an ienumerable collection of characters... not a datatable... so how do I convert back easily without manually doing a loop?
I've a collection with the data like this.[code]...
how can select the distinct data using linq?
I have set up a class to hold song information - artist, title. I then created another class that containg a BindingList(of clsSong). I use this binding list to create a data object that can be used to create an RDLC report. This all works. Now I am trying to remove duplicates from the binding list so they don't show up twice on the report. I can't figure out how to get a distinct list for my report. [code]...
View 3 RepliesI used the following code to select unique values from the database [code]And it does not retrieve the unique values, it remains the same. But if I use only SELECT DISTINCT Author FROM tblBook it works fine.
View 3 RepliesI'm pretty new in Linq and the first problem I've is to select the Distinct values from a ObservableCollection( Of T)
I've tried with[code]...
I'm using LINQ to SQL to select some columns from one table. I want to get rid of the duplicate result also.
Dim customer = (From cus In db.Customers Select cus.CustomerId, cus.CustomerName).Distinct
Result:
1 David
2 James
1 David
3 Smith
2 James
5 Joe
Wanted result:
1 David
2 James
3 Smith
5 Joe
Can anyone show me how to get the wanted result?
I am trying to get distinct rows based on multiple columns (attribute1_name, attribute2_name) and get datarows from datatable using Linq-to-Dataset.[code]How to do thin Linq-to-dataset?
View 3 RepliesIs it possible to select distinct values from a DataTable?
View 5 RepliesI have an EnumerableRowCollection that looks like the following:
VendorCode | GroupType | Variance
01165 G .16
01165 G .16
01165 CH .16
01165 CH .18
07754 G .25
07754 G .25
07754 G .39
Essentially, this is a massive list of vendor codes, their groups, and price variances. I need to compose a query that will create a distinct list vendor codes and group types. The catch, however, is that I need to evaluate all of the variances associated with that particular VendorCode/GroupType to see if they are all the same - it they are not, I need to return some way of signifying that the group has a "custom" variance, otherwise it needs to return the value (ie: if they are all .16, then return .16, if there are multiple values, return "custom")
The result would look like this, based off of the list I showed above.
VendorCode | GroupType | Variance
01165 G .16
01165 CH custom
07754 G custom
I have no trouble getting a distinct list of VendorCode/GroupType - this is what I have so far:
Dim distinctList = From q In query Select q.VendorCode, q.GroupType, (evaluated q.Variance here?) Distinct
(where "query" is an EnumerableRowCollection(Of (anonymous type)))
I'm at a loss, though, on how to evaluate the variance property to get the result that I need?
My particular example is fairly complex but I think the concept would apply equally to something like a logging system so I'll use that instead for ease of explanation. It's a ficticious example, please don't harp on or agonise over what is achitectually, programatically or morally wrong with the example itself
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I don't want to 'cheat' and resort to a long-winded way of doing it when performance isn't critical here and I'm moderately confident it can be done in a single LINQ statement.
I have an array with wild character at the end. I use the value in this array in Select statement. Some times the array has same values. I want only distinct values in the array before the select statment.
Code:
for i=0 to count
select * from tbl where item like ' " & itemname(i) & "'
next
I need distinct element in itemname array.
basically i'm trying to reproduce the following mssql query as LINQ
SELECT DISTINCT [TABLENAME], [COLUMNNAME] FROM [DATATABLE]
the closest i've got is
Dim query = (From row As DataRow In ds.Tables("DATATABLE").Rows _
Select row("COLUMNNAME") ,row("TABLENAME").Distinct
when i do the above i get the error
Range variable name can be inferred only from a simple or qualified name with no arguments.
i was sort of expecting it to return a collection that i could then iterate through and perform actions for each entry. maybe a datarow collection?
As a complete LINQ newb, i'm not sure what i'm missing.
i've tried variations on
Select new with { row("COLUMNNAME") ,row("TABLENAME")}
and get:
Anonymous type member name can be inferred only from a simple or qualified name with no arguments.
to get around this i've tried
Dim query = From r In ds.Tables("DATATABLE").AsEnumerable _
Select New String(1) {r("TABLENAME"), r("COLUMNNAME")} Distinct
however it doesn't seem to be doing the distinct thing properly.
I have a datatable as shown in the figure. Let me explain my required based on this image. I have 7 rows of data. The rows 1 and 2 contains columns till UnitSqcNo same. I want only row 3 among the two. In general I want select all the rows with distinct model, unittype, unit and rest with greater CompId. ie the table should look like
View 1 RepliesI want to select to multiple sql tables using select query in vb.net..I have 2columns in sql table..I have tried this query.. But i'm getting error.
TextBox11.Text = Val(27)
cmd = New SqlCommand("SELECT outside,power FROM vijay21 INNER JOIN vijay22 ON vijay21.outside=vijay22.outside WHERE outside BETWEEN " & Val(TextBox11.Text) & " AND " &
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I am trying to distinct on multiple columns and get datarows from datatable. but getting error.
Dim query As IEnumerable(Of DataRow) =
(From row As DataRow In SourceTable.AsEnumerable() _
Select row.Field(Of String)("ColumnName1"),
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I want another datatable with distinct row based on given columns from SourceTable.
I have a 5 tables in my database and i want to access all my tables togather at a time.e.g.I have a code for one table i.e. rs.Open "select * from Group_info", con, adOpenDynamic, adLockBatchOptimistic. instead of Group_info table i want to access 5 tables also as Login_table,User_info table,group_name table etc. How i do that
View 11 RepliesI have a data grid view on a form which is currently filled with the following query:
SELECT TopicCode, TopicName, NoOfCourses, Lev FROM tblTopics WHERE TopicCode = @TopicCode1(Where I obviously pass a TopicCode parameter)
However, I have added two custom columns to the data grid view, and the values that i want be in here are in a different table than the query i'm using to fill the data grid view.is it possible to "nest" queries? which will allow me to select fields from two different tables?
Example:SELECT TopicCode, TopicName, NoOfCourses, Duration, Lev FROM tblTopics AND SELECT StartDate, EndDate FROM tblSubscriptions WHERE TopicCode = @TopicCode1
Possible? or not?
It is possible to check two different MySQL tables from the same sub?
For instance:
Dim Connection As MySqlConnection
Connection = New MySqlConnection
Connection.ConnectionString = "server=server; user id=userid; password=password; database=database"
Try
Connection.Open()
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What I'm trying to get is something like an "or" function. If TextBox1.Text isn't in the database, then check if TextBox2.Text or TextBox3.Text is in the database.
i have more than 10 table but same column names i need to collect datas from these table for example i need to select name column from 10 tables how to do this
View 8 Repliesthere are three tables in dbf , table1,2,3 respectively all are contains similar structure but different data Structure : S.no Quiz Question i want the query which select the Quiz Question/records through user given Range from Textbox1.text to Textbox2.text
View 3 RepliesMy project is a standalone application with lots data retrieval and sometimes data update.No SQL server or connection provided)Here is sample code
Dim objDS As New DataSet("Quesetion")
Dim dtBook As DataTable = objDS.Tables.Add("Book")
Dim dtChapter As DataTable = objDS.Tables.Add("Chpater")
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I have three tables Student, TimeSheet and TimeRecord.
Talbe columns:
Student : StudentId, FirstName,
LastName
TimeSheet: TimeSheetId,StudentId, IsActive
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in below code there is syntax error in from Clause but i think every thing looks fine iam using access database thx and relation is fine between thes two table
Public Function GetGridData() As DataTable
Dim dt As New DataTable
Try
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am developing a project and i am trying to use this code with my table which is under microsoft access 2010
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