Is it possible to have a quick and easy way of retrieving the last 10 records from a table?
Currently what I have been doing is retrieving all the records then one-by-one cylcing through each record until I have the last 10. To me this seems to have a lot of over-head reading each record. I just wondered if there was a quicker way of doing it.
Like we can retreive all the records from a table using this method:
While (Not rst.EOF)
....
End While
How to retrieve all the records when using OleDbConnection?
I can retrieve records from my Database fine, but I'm having trouble updating records. I am getting a syntax error on [code] I get this error when I change the Last Name (Row 0, Column 1). [code]
View 4 RepliesI have a database with 3 tables: Student, Unavailability and Duty.The fields for Student are entered in a form I have. One of the fields in Unavailability is filled by a form, the other fields are an autonumber and a foreign key to the Student table.ow I want records in the Duty table to be created and automatically filled in depending on what the values of the fields are in the Student table.For example, If the Boarder field in the Student table is 'yes' then I want the Duty Number field in the Duty table to be '1', '3' and '4'. If it is 'no' then I want the value to be '2' and '5'. I recognize it will have to create several different records to incorporate the different duty numbers for each StudentID. Obviously this will require an if statement, however this is my first time implementing a database with my limited experience with programming and Visual Basic, so I don't know how to refer to the specific fields in a table and set the value of other fields depending on the data in other fields.
View 6 RepliesI have this piece of code wich works perfectly when inserting records into one table using records from another table. My question is that now i need to create another table by using records from 3 other tables (tables are related). Can i use aliases on the column names, like on Oracle SqlPlus? How will be the syntax of the 'INSERT INTO SQL statement?
Dim MyConn As ADODB.Connection
Dim MyRecSet As ADODB.Recordset
Dim tmpSQL As String
MyConn = New ADODB.Connection
[code]....
I want to do something like this:
Code:
'create a dataset and a table
Dim ds As New DataSet
[code].....
I'm using vb.net. Usually I used the SQL Server SQLComamnd but here I need to use an ADO. I have this but I'm stuck at the end of it how to get the data? [code] How do I actually retrieve this record?Is there something akin to the SQLCommand that has Reader?
View 1 RepliesI wish to retrieve all records for a particular day. The user can choose a date from a calendar and once click on ENTER,all the records for that day will be display out. I am able to choose the date using MonthCalendar and display it onto a label. But the sql statement of displaying it onto a datagridview shows no result.
This is my sql statement:
HTML
MyCommand = New OleDbCommand("SELECT * FROM cable WHERE 'Date_Time' = "& Label6.Text,MyConnection)
My records in MS Access is in this format:
mm/dd/yyyy xx:xx:xx AM/PM
I would like to do like this...When I click a button, it will capture the times the button had been click retrieve 10 records at one time...For example, when the button being click for first time, it will retrieve the first 10 records and put into 10 textbox. Then if the the button being click for second time, it will retrieve the records from 11 to 20 and put into 10 textbox and so on. I had the following codes:
[Code]....
Okay, So I am trying to get my vb.NET Application to retrieve all the data in the database. My connection to mySQL is working and i have been able to fill a DataGrid with data from the database a function[code]...
View 13 RepliesI do this in Oracle databases just in a snap, but now I have to do it in VB using ADODB and I don't know how to do it.
I have two Access 2007 tables. Table A contains: Col1 (text), Col2 (text), Col3(date), Col4(amount), Col5(text)
Table B contains Col1(date), Col2(amount) What I need to do is to insert into table B the records of table A (col4 summed) grouped by date of table A. The date is a variable contained in a text box so it cannot be hardcoded into the SQL statement.
theyI had a asp.net (vb) web application to store work overtime (OT) records. In SQL server, the OT table likes this, e.g.:
[Code]...
As user will input previous date OT records, so the records in db will not be in sequence. the date of records#14 is before records#13. if user want to know which OT records cover the last 2 hours, the system should retrieve record #15 (90mins) & #13 (30mins) because they covers the final 2 hours. How to write the SQL statement to retrieve the records?
Dim cmd2 As New OleDbCommand("SELECT Product_name FROM Products WHERE Quantity <= 5 ", cn)[code]..
This code outputs all the products in a list box which are below a quantity of 5, however for those products i wud also like to retrieve the maximum stock level which was assigned to all of them so i can calculate how much more is needed to fulfill the maximum stock level
Here is what I'm working with:
Dim connstr = "data source=mydatasource;initial catalog=gcs_dw;persist security info=True;user id=myuser;password=mypassword;Asynchronous Processing=True"
Dim sqlquery = "SELECT * FROM Customer WHERE CITY = 'Anytown'"
Dim connection As SqlConnection = New SqlConnection(connstr)
connection.Open()
[Code] .....
As you can see, I'm attempting to display the results of the query to the commandline and currently all it is displaying is "System.Data.SqlClient.SqlDataReader". Where are the results of my sql query going and why can't I retrieve them?
I know this is basic, but my mind is totally blanc. I'm trying to retrieve all records from a table with a specific code.
Dim cmd As New MySqlCommand("SELECT myValueRow FROM myTable WHERE searchRow = 'test'", myconnection)
myreader = cm.executereader
[Code]...
I have a database table that has in it, for example:
Room1
Room2
Room3
[code].....
I know how to loop through a GridView and extract each row using the for each loop as below, but I was looking for a easy way to loop through the datagrid and say extract the last 20 rows? Is it possible to go through in reverse order in vb.net?
For Each row As GridViewRow In InventHistoryGridView.Rows
I tried using the following codes but it's not working,
Dim Con As oledbconnection = new oledbconnection()
con.connectionstring = "Provider = Microsof.jet.OLEDB.4.0; Source=c:\program file\database.mdb"
dim sqlcmd as oledbcommand = new system.data.oledb.oledbcommand()
sqlcmd.commandtype=commandtype.storedprocedure
sqlcmd.commandtext = "query"
[Code]...
i have a query as follow:
gconn.BeginTrans
strSQL = "INSERT table_name (....) " & _
"SELECT fields_name FROM table_name2..." & _
[code].....
I am basically trying to create some records using Structures as you can see below, however the value of Index doesnt seem to be incrementing as I am assigning it to txtCustomerId.text each time form loads, however the value of the text box remains at 1000 all the time
Code:
Public Class Form1
Dim NumberOfCustomers As Integer
Dim Index As Integer
[Code].....
I am a high school student and i am teaching myself VB, C# and C++... it is a slow process containing mainly trial and error, looking up things online, and when the time is right asking assistance from people who know more then I.
I am currently creating a VB program that creates a database of questions, and the same or separate database. using them questions it can initiate a quiz that will save results in a different database for each student. I am having difficulties getting the code right for reading the databases, and getting it to move to the next portion of the database for each question... a little more info:
Question # = Primary key (there will not be more then 1 of the same # problem)
Question Type = i am using different integers right now to specify if the question is a T/F, Multiple Choice, Open info Et Cetra.... Question Answer = Correct answer Alt answer (x3) = option to add other answers for multiple choice problems...
I don't know exactly how to get it to read a problem and when clicking a next button on a form to have it go to the next question in the database..
I am not new to vb but still an amateur, however, I am still learning linking vb apps to mysql, here is where my troubles begin. I am stuck and been trying for hours on end to get past this problem. It's starting to hurt my head! I am sure others have similar problems.I posted my imports and the module I put my public sub in. The sub is called as a form loads.The Error is:
An unhandled exception of type 'MySql.Data.Types.MySqlConversionException' occurred in MySql.Data.dll
Additional information: Unable to convert MySQL date/time value to System.DateTime
[code].....
I have combobox for year and combobox for month concatenated to make the date format "2012-01" My db field is RecordDate and is smallDateTime In my select statement im trying to use the left function to find match my concatenated string to the RecordDate field.Here is my code, hopefully someone can help me. Currently im getting the error "Conversion failed when converting date and/or time from character string."
Dim newRecordDate As String = (CStr(ComboBox2.SelectedValue)) & "-" & val1
Dim val10 As String = CStr(Convert.ToDateTime(newRecordDate))
Dim val21 As String = Microsoft.VisualBasic.Right(val10, 7)
MsgBox(val10)
[code]....
I have a DataGridView bound to a non-SQL Server database.I need to allow users to edit existing records but under certain circumstances I need to intercept the edit and instead of committing and updating the dataset I need to delete the edited record and re-add it as a new record.I have tried using every event I can think of to do this but haven't managed to get it right. [code] This almost works but sometimes completely messes up and re-adds rows twice and all kinds of other bad side effects.
View 9 RepliesAn order can have many OrderDetails, and a Product can be on many different orders. The OrderDetail table just has the OrderID and productID, so there is essentially a many-to-many between order and product).I have a form for the user to enter a new order. I want to have an unbound box that contains the names of all the products, and to be able to drag these names into a box under the order, to add a new OrderDetail record using the productID of the dragged order along with our orderID.
View 1 RepliesIf I use the CmdObj.ExecuteNonQuery() I got an error
I'm not having an open connectoin.
Rather than running numerous queries in Access I am trying to write a front end for a DB2 database. The Access database is getting to a size that it is causing Access 2007 to have reliability issues and frequent compacting is required. I have created the Dataset, the Table Adaptors, and the Connection String already, but when I put in a bit of code in to fill the Table Adaptors the remote connection I have to work is going crazy (chewed up about 180MB before I realised it was pulling data from work).
Before I started the project I copied the .accdb to my local PC HDD and I pointed the connection string to it, but it still looks like it is trying to pull data from the work network. If it was a small database I wouldnt be concerned but it is pulling major data every time I run it. I have only 2 out of the 4 Table Adaptors running and it didnt fill them even after 10 minutes.
Here is the code I was trying to run... Server name has been substituted for Server for obvious work reasons.
Because the tables are so large I was looking for a way to pull only the columns I need to from the tables, I tried adding .SOFT_ID to the first line of code but the TA spat the dummy message below...
Value of type 'System.Data.DataColumn' cannot be converted to Application_Name.DS_DB2Database.Server_SOFTDataTable'.
Code:
Me.TA_ServerSOFT.Fill(Me.DS_DB2Database.ServerSOFT.SOFT_ID)
Me.TA_ServerSOFT_FOUND.Fill(Me.DS_DB2Database.ServerSOFT_FOUND)
Me.TA_ServerHARD.Fill(Me.DS_DB2Database.ServerHARD)
Me.TA_ServerREF_SUP.Fill(Me.DS_DB2Database.ServerREF_SUP)
I would also like to pull just the data columns I need to speed up the query.
Note: In case youre wondering why I am not connecting directly to the DB2 database. I currently dont know where it is stored and while leveraging Access I am trying to put a level of separation between the app and the db for the time being, later I will try connect directly.
I have 10 IP address I need saved so that when the programed is closed the user doesn't have to re type them all back in. To get around this I created a database that would store the values. My table contains one Field "host" and then has all 10 IP addresses listed below that.I'm trying to figure out how to make a text box on my form look at a certain row in a SQLServer 2005 table.
For example:
txtIP1.text = Row 1 of SQL table
txtIP2.text = Row 2 of SQL table
Here is what I have in my Form load Event. This works, but again I need the second rows value to show in the second txtbox.
[Code]...
What is the easiest method of storing data and retrieving it using VB? FYI, I have not used Access before. It will be a movie database that stores title genre, etc. I thought about using a text file but i think thats crude and ran across this site:
View 1 RepliesSo I've been playing around with SQL strings in VB 2008, and trying to retrieve records from a database and display them in a data grid view. This is the part of the code that gets the fields and displays them in the data grid view:
[Code]...