i want to check if datasets have changes and after that use msgbox (vbYesNoCancel) when program closes ,when i wrote this code it had error "Operator 'Or' is not defined for types 'System.Data.dataset' and Boolean"..[code]
View 2 RepliesI am tightening up my coding with the Option Strict set to ON. It has now produced alot of errors. An example of this is:
If AllocatedDGV.Rows(i).Cells("RoomNumber").Value = RoomsAvailableDGV.Rows(j).Cells("RoomName").Value Then
It gives me the following error: Option Strict On disallows operands of type Object for operator '='. Use the 'Is' operator to test for object identity.
I need to write an interface to get data to/from our data files.
We have a low level class that holds field values for each record read from the files.
This just holds two values, the value read from the file (DBValue) and the updated value that may need to be written back to the file (CurrentValue).
These values may be any of the standard value types (integer, date etc) or a string.
Either value (DBValue or CurrentValue) may be null if not defined.
I have written the class to manage this data which works fine while option strict is NOT on.
But we have an office policy of having option strict on all the time.
When I put option strict on, my object value comparisons fail with the error: "Option Strict On disallows operands of type Object for operator '='. Use the 'Is' operator to test for object identity."
Question, how should I change the following code to handle option strict on ...
This is all running on Visual Studio 2010
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Possible Duplicate: Is there a conditional ternary operator in VB.NET?
Can we use Coalesce operator(??) and conditional ternary operator(:) in VB.NET as in C#?
I want to perform equality comparison in VB.NET and cannot get it to work. Error: value of type Boolean can not be converted to System.Drawing.PointF
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I'm trying to work with an ODBC driver for Interbase in VS2008 (vb). I succesfully inserted the data tables I want to use in the project datasource. Then I want to add some rows in one of the tables of the datasource. I used myDataSet.addTABLENAMErow(field1, field2, ...).The compiler gives me no error, but when I open the database with InterbaseConsole, the line I've add is not there. Do I do something wrong? Must I open/save the database (how do I do so). I've tried meDataSet.AcceptChanges whitout result.I'm not used to work with Datasets and tables...
View 1 RepliesAnyway to view the content of a dataset or datatable in debug? I don't mean looking up a specific element of the dataset but to view the hole thing.
View 4 Repliesdifference between the two statements given below
1. Dim ds as new DataSet
2.Dim ds as DataSet = New DataSet
I'm trying to combine two datasets, each with 1 datatable and each having the same schemas. Datatable 1 would have a list of records. Datatable two may, or may no, have some or all of the records from table 1 plus more records. I would like to remove all the records from table 2 that are present in table 1.
This is what I got so far:
For Each table1 As DataTable In ds.Tables
For Each row1 As DataRow In ds.Tables(0).Rows
ds.Tables(0).PrimaryKey = New DataColumn() {ds.Tables(0).Columns(0)} 'Where 0 is the index of the column that's your key
row2 = ds2.Tables(0).Rows.Find(row1("ID"))
'if its found, delete it
Next
Next
how to join two datasets together.
First Dataset
Dim sql As String
sql = "SELECT payment.Debtor, SUM(Value_invoice) AS before_this_month,debtor.nama FROM Payment INNER JOIN dbo.debtor ON Payment.Debtor = debtor.debtor" & _
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Now i just want to either inner join or left join PaymentBeforeThisMonth and PaymentThisMonth into another dataset?
I have a dataset that contains only employee ID's. I need to loop through that dataset and for each employee ID I need to loop through several other datasets and pull data. I need help with this looping syntax. Here is a sample of some code that I am receiving an error with:
Dim EMPID as Integer
Dim CommandEmpid As New OleDb.OleDbCommand
Dim EmpidDS As New DataSet
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I have a form that needs to load data for 20 different combo boxes - the data is always the same. To get the combo boxes to function properly i need to create a separate dataset for each combo box. Doing this when the form loads takes it about 7 seconds each time a search result is double clicked and the form pops up displaying the correct data. The form is bound to the main table. Is there a way to store these data sets in memory somewhere so the user can close the form but still have them loaded? I can put this code behind the login form and it works until the form is closed, then the combo's no longer load.[code]
View 8 RepliesI want to use my main dataset (dbds) on a second form. It's simple, on my main form, the user clicks a button, opens a new form, they enter an item number and I want to find that row, and change a value in another column of that same row, and have that be in effect onthe main dataset to send back to the database.[code]...
View 1 RepliesI have declared a dataset (let's call it 'Fred') as public in a VARs module. In the main form in a sub routine called at the start of the project I connect to an Excel spreadsheet and read it into the 'Fred' dataset into one table (called 'Table') I then bind the dataset table to a datagridview and I can see the spreadsheet. Which is very nice :-)
Having loaded the dataset I want to be able to get some values so I created a button and used the following
msg = Fred.Tables("Table").Rows(0).Item("Name")
I think this should get the value in the first row and in the column called 'Name' in the table called 'Table'
But I get an error when I click the button 'Object reference not set to an instance of an object' which I think means I need to use the 'New' keyword...
So I added to the button
Dim Fred = New DataSet
But I get the same error.
Now I have to admit that I've never really got my head around how to use the 'New' keyword and would have hoped to be able to get data from a dataset through my entire project - especially as I've declared it as 'Public'. Surely if I use 'New' all over the place then I create new datasets
What is the best way for me to have several datasets ?i've thought about creating a routine for creating datasets with a number in their names, each one with the desired data, but that's not very intelligent (although might work)i'd like to create what would be like an "ARRAY OF DATASETS"
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(obs, i've done the same code loading one XML to one dataset and it works perfectly, i've gone back and forth more than one time to assure that it isn't just a logical mistake, it's syntax and lack of programming knowlegde.
I need to very quickly write an exe system on a laptop where when the laptops are connected to the network they read a database table and store the data locally, so staff can use the laptop while they roam.The laptops have quite small capacity and the company would prefer not to use SQL Express or Access.
My question is, can the data initially be downloaded into the exe application via a dataadapter and dataset, and will that dataset the retain the downloaded data, or will I need to ensure the dataset is written to an XML file and then loaded/unloaded each time the laptop application is started while the staff are travelling ?
What I'm looking for are videos in vb.net for console application that will show me how to use DataSets and TableAdapters step by step. Please provide links
View 4 RepliesI'm using the MYSQL .NET connector with an adapter to fill a dataset from a SELECT statement. Between different SELECT statements I use the DataSet.Clear() function. The Getxml shows me that the dataset is empty, however when cycling through the Table's columns, I have all the columns from all the tables used in prior SELECT statements.
How do I go about that without Dimming new Datasets for each table?
I'm not sure, if this is possible, but what I would like to do is fill a DataTable with results from "SELECT TABLE_NAME FROM myDB.INFORMATION_SCHEMA.TABLES" and then fill individual data sets in a For Each loop. I'm able to fill a data table with the table names I want to populate, and I can update my SQL Command of the SqlDataAdapter, but when I try to fill the data set by using the results from the row, I run into an error that I can not convert a string to a DataTable or DataSet. Each DataSet is named just like the table name. The code is at home, so I can't paste all of it here, but hopefully, you understand, what I mean. A small amount of the code that I remember is below, and this is inside a Using block connecting to a SQL Server.For Each row as DataRow in dt.rows
tsql = new SqlCommand("SELECT * FROM myDB.." + row("TABLE_NAME"), mycon)
oleda.SelectCommand = tsql
oleda.Fill(row("TABLE_NAME"))
I have a report where I need the same data, but for four separate date ranges. Currently this data is based on one month, so it's just one dataset. But now I am trying to do this with four separate datasets, where each one is filtered on each of the four date ranges. I setup my WHILE loop to loop thru all four dates. But I'm having trouble now with distinct naming these datasets. Is this the best way to do this? It looks like if I used multiple datatables for one dataset, I'd have to define each datatable column. Here is my current dataset commandstring
View 8 RepliesI'm trying to merge two datasets based on these rules:
1. With ds1 and ds2, If the Unique Key from ds1 is not found in ds2, copy it to ds2 and move to next row in the table, else, goto the next part
2. If the unique key in ds2 is found in ds1, check the DateLastEdited row.
a. If DateLastEdited in ds2 is greater then in ds1, copy the row from ds2 to ds1, else , do nothing
I'm just having trouble with the loops. Here's what I have:
Dim ds1 As DataSet = fillNetwork() 'this function fills ds1 with the dataset from a table found on a network
Dim ds2 As DataSet = fillLocal() 'this function fills ds1 with the dataset from a table found on local drive
Dim returnRows() As System.Data.DataRow = Nothing
For Each dtDs1 In ds1.Tables
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This bit of code is just trying to segregate the one that are in both tables from the ones that are just in one table.
How To Join Two Datatables From Different Datasets (With One Commn Column) ???
View 2 RepliesAll I really want to do is a join. Table 1 and Table 2 both have a number that would link the two together. I want to join two fields from Table 2 onto Table 1. I need to have two datasets because there are two different connections being made.I want to push this onto a DataGridView, which only allows a single datasource. So I'm thinking I would need to make a temp table somehow, but since I'm pulling from two different datasets I don't know if that's possible.
View 1 RepliesI have two datasets called ds and ds1 that I want to merge into a grid. I get data from the first dataset to display in the grid but the second dataset where I want to display a count I don't get any data from it. I am trying a ds.Merge(ds1). here is the code i have for the sub.
1. Public Sub LoadSessionDateGrid(ByVal iSchool As Integer, ByVal iProgram As Integer)
2. Try
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I have two datasets called ds and ds1 that I want to merge into a grid. I get data from the first dataset to display in the grid but the second dataset where I want to display a count I don't get any data from it. I am trying a ds.Merge(ds1). here is the code i have for the sub. What am I doing incorrectly?
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This is my first attempt at writing a console App that accesses data on my SQL server. The application is a simple process that would run each night to do some database cleanup.
Up to now all my dataset access has been through windows forms, and its really easy to bind the dataset to the code, by simply binding a dataset column to a field on the form.... BUT there is no form in the console APP!.
I know I can code tedious lines of code to define the dataset, and the SQL etc etc, but there has to a simple method like there is for forms.
I have a DB application that I've created using the Datasources wizard. A particular insert requires that two inserts must be done at the same time meaning that it has got to use transaction. how to use transaction in this situation.Only performance counts!
View 5 RepliesI am novice at best with VB. I have a dataset built from a complex query. Well I have a lot more items in the dataset than I wish to show in a datagridview. Some items will be used for other purposes at the time, filling txt boxes, dropdowns, etc...all independent of the dgv. I am lost at how to fill just a 3 or 4 of the items rather than just filling the entire thing. So, instead of just filling the entire ds into the grid, how would I fill in selected columns into the datagrid that has specifically named columns at runtime?
View 2 RepliesI have a taskfactory application that generates new tasks where a task is running a project exe file that involves a lot of classes. Part of the task process involves declaring a dataset and adding a single datatable to the dataset which is then populated with content from results of a sql query. This datatable is then used in the next class and involves iterating through the table and deleting the rows it has already used. When initiating a new task I assume that it will declare its own datatable and dataset but not sure if this will work.
View 2 RepliesI have 4 ComboBoxen and 1 DatagridView into one Form. I make a code, for binding with 5 tables, each is own dataSet and dataAdaptor Is it possible to use one DataSet and one DataAdaptor for 5 Tables, so my code become shorter.
I think the solution is a SQL SELECT query, but i dont no for sure.If it is a SELECT query, ore something else, cane anybody help with make the code i need.
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