Use Select Distinct From A Tables Row In MS Access?
Oct 29, 2010
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.
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)
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.
I 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 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]...
I 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.
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?
I 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.
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
I 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 " &
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
I 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
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
there 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
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