Use Variables In A SQL Statement
Apr 16, 2010[code]How do I use variables in a SQL statement?
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Declared Variables With SQL Statement?
Aug 20, 2010I have a simple table in an access database that I'm using in a VS2010 project. I have a combobox control that a user can select the horse power of a motor. I then take that selected value from the control and copy it to a string variable called gstrSelectedHP. All I want to do is run a query that will pull up the full load amps of that horse power motor from the table. I have the query already, but I need to somehow put the gstrSelectedHP in the WHERE part of the query so that it only returns that value.
View 14 RepliesUse Variables In A SQL Statement In 2008?
Apr 16, 2010I got this in my SQL statement. I "BOLDED" the problem.SELECT OrderID, CustomerID, EmployeeID, OrderDate, RequiredDate, ShippedDate, ShipVia, Freight, ShipName, ShipAddressShipCity, ShipRegion, ShipPostalCode, ShipCountry FROM Orders WHERE CustomerID =@CustomerID
View 5 RepliesVS 2008 How To Use Variables In A SQL Statement?
Apr 16, 2010I got this in my SQL statement. I "BOLDED" the problem.
SELECT OrderID, CustomerID, EmployeeID, OrderDate, RequiredDate, ShippedDate, ShipVia, Freight, ShipName, ShipAddress, ShipCity, ShipRegion, ShipPostalCode, ShipCountry FROM Orders
[code]......
Combining Variables In SqlCeCommand Statement?
Apr 11, 2011with the following code example:
T04Command04 = New SqlCeCommand("Update GameResults Set CN01=@T04Var02 Where Counter=@T04Var03", T04Database01)
T04Command04.Parameters.AddWithValue("@T04Var02", T04N01)
T04Command03.Parameters.Add("@T04Var03", T04ClnRec01)
T04Command04.ExecuteNonQuery()
I am trying to use two different variables in this SqlCeCommand series, to (1) update only a particular record in the database (2) with a particular variable value. However, I get the following error:
"An SqlCeParameter with ParameterName 't04var03' is not contained by this SqlCeParameterCollection."
Linq Using Variables In Order By Statement?
May 18, 2012Dim gg = From gs In AllData_TableList Order By gs.Biology Descending, gs.ChemistryDescending, gs.English Descending, gs.Frensh DescendingAll I need is to make this Statement order Dynamically like this
Dim Variable1 as string=Biology
Dim Variable2 as string=Chemistry
Dim Variable3 as string=English
[code].....
Dynamic Variables In Linq Select Statement?
Nov 23, 2009I have a listbox that is dynamically filled by certain values depending on what table has been selected from another list box. Once a value is selected, it is being graphed vs a date & time range. With my ignorance of linq: depending on what value is selected, the linq to sql statement I need to create to grab data from my database is different as I can't use an index on an anonymous type.
result = From t In db.APS _
Where t.DateTime >= startDate And _
t.DateTime <= finishDate And t.Weight = weight _
Select t.DateTime, t.TotalConcentration
t.TotalConcentration should be selected if my listbox value is "Total Concentration", but if it's something else, like "Temperature" or "Flow Rate" (connected to appropreate database columns) - this method obviously isn't going to work. I need to be able to dynamically select a specific column from the anonymous type list, or use some other method I'm unaware of to do this.
Select Case Statement With Constant Variables
Nov 18, 2009While measuring the select case performance I encounter a strange behavior of Select Case statement with the constant expression. I don't understand why its behavior is dependent on the values to be compared.
[Code]...
Sql Server - Input Variables As Stored Procedure Statement
Feb 4, 2012My stored procedure:
[Code]...
So my idea is to have (in my VB.net project) a string that could dynamically change the stored procedure "Future"
Using Variables With INSERT INTO - VALUES Statement Within OleDb Command
Nov 19, 2009I am using an INSERT INTO ... VALUES statement in the following matter to insert data into a new row of a database:
[Code]...
How can I substitute variables for the explicit values of X and Y in this statement (for example, variables XName, XAddress supplied by user input via text box)?
2008 - If > Statement - Does It Matter That Variables Are Marked As Strings Vs Integers
Feb 9, 2009I have a "if This > That then" statement, that doesn't seem to work, as it triggers regardless that "This" is smaller than "that". Does it matter that these variables are marked as strings vs integers?
View 8 RepliesVS 2008 - Take A String Of Variables With A Common Delimiter And Break It All Back Out Into Separate Variables
Dec 11, 2011Last year (2010) I came across a FANTASTIC command that allowed me to take a string of variables with a common delimiter and break it all back out into separate variables (possibly an array) with one statement.
[Code]...
As long as the delimiter was a unique specifiable character, this one-statement command could break it out into elements. my memory and point me in the right direction.
Passing Multiple Byref Variables / Variables Fail To Change Calling Funct W/ Invoke
Sep 27, 2010I have code, shown below, that works all except for 1 thing: The variables being passed byRef get passed, but once modified in the else section of the "if me.invokerequired" code of RecordData, the variables are never updated in the calling function. To reiterate, the calling function does not receive the updated data that is in the variables custid and amt.When debugging, I see the data change in the else section of "if me.invokerequired", but once it returns from the callback the data is missing.[code]
View 15 RepliesDefine Some Global Variables Of A Class - Variables Occupy Memory?
Mar 23, 2012I define some global variables of a class as follows:
Private Class MyClass
Private var1 as Decimal
Private list1 as List(Of string)[code].....
But I found that after this form is closed, all above variables, var1, list1, list2 still exist in memory. I thought they should be collected by gc since the form is already disposed as I confirmed.
Add: I have monitored half an hour after the form is closed. But these variables are not collected by gc. I have an automatic update procedure on the form which uses above variables.Since the above variables still hold values, the automatic update procedure is always called which causes exception. (One quick fix is to check if form.isDisposed in update procedure. But I do not think this is elegeant. Besides, these variables occupy memory.)
Memory Used In Declaring Variables Are Reclaimed By The OS When These Variables Go Out Of Scope?
Jan 7, 2010Does the memory used in declaring variables are reclaimed by the OS when these variables go out of scope?Does the memory used be released by setting thier value to nothing? if not, then how can I force the garbage collector to run or excecute at a certain/desired time..How about in Windows Forms..How can we make sure that the memory used in initializing and showing forms be released if those forms were closed?
View 13 RepliesMultithreading: Reading/setting Variables, And Passing Variables?
Mar 8, 2011Question 1: What is the difference between "Background Worker" and "Worker Pool" as indicated within the MSDN samples provided.
Question 2: I noticed while using, AddressOf _Function_, variables cannot be passed; what would be an efficient solution to this?
Question 3: While using multithreading is it required to invoke before setting variables, or only form properties?
Question 4: While using System.Net.Sockets is it safe/efficient to use Application.DoEvents while waiting for new data; or would be using a Do While loop be fine without DoEvents since the action would be multithreaded? Note: there can be up to 2000-3000 sockets in use at a time.
Use Variables Or Properties, And Global Or Static Variables In A Class?
Jun 9, 2012I'm new in .NET programming.I have a class Form1 that includes Button1_Click event.Button1_Click creates a multiple Text Boxies at run time)Here is the class:
Public Class Form1
Dim shiftDown As Integer
Dim counter As Integer
[code].....
SQL Statement Doesn't Work - INSERT Statement Works Fine In The Form Load But Not In The Button Click Event?
Oct 14, 2009See
Public Class Form1
Dim sql As String
Dim conn As New OleDb.OleDbConnection
Dim da As New OleDb.OleDbDataAdapter
[CODE]...
The problem, The INSERT statement works fine in the form load but not in the button click event?
If <expression> Then <statement [:statement]> Else [statements] In Concrete Form?
Jan 1, 2010I was convinced that If <expression> Then <statement [:statement]> Else [statements] in concrete form of If a = b Then SayHello() Else SayBye() End has sense. I read article on msdn on If-then-else, but I forgot why I was reading, so I concluded, that snippet above means this
If a = b Then HelloIsSaid : IsNotEnded Else ByeIsSaid : IsEnded But I have tested it now, and I see, that Else without statement is nothing more than decoration. It would be pretty good if it had function I described. Do you think its good request? Or do you know any circumstance where this Else has some function?
Making A Next Statement Into A Loop Statement In Visual Basic?
Jun 8, 2009y friend and I are re-learning Visual Basic, and we are stumped on this bit of code.
For intAsterisks As Integer = 0 To intLine - 1
lblAsterisks.Text = lblAsterisks.Text + "*"
Next
Sql - Perform An Inline Select Statement In A LINQ Statement?
Jun 24, 2011I have the following SQL:
[Code]...
I want to put it (the select count statement) in this LINQ statement so I can get the sales count in my linq statement: Dim TheLeads = (From L In DB.Leads Where L.IsDeleted = False Select L).ToList() Is this possible to do in LINQ?
Change The Exit Statement To A Continue Statement?
Feb 23, 2009add an if statement and an exit statement to my do loop that exits when my future value (FV) is greater than 1000, then to change the exit statement to a continue statement so my loop will continue even though my fv is greater then 1000, point is to get this to run even though my if statement doesnt do anything. problem something wrong in my code and an exception error (xception of type 'System.OverflowException' occurred in mscorlib.dll)
so can someone show me where or why I have an error is, what am I overthinking now! I could use a hint, OMG i could use a tutor for that matter
[Code]...
ElseIf Statement Into A Select Case Statement?
Jun 23, 2010A co-worker wants to convert the following IfThenElseIf statement into a Select Case statement.
Explain why this is not possible.
If temperature = 100 Then
X = 0
ElseIf population > 1000 Then
X = 1
ElseIf rate < .1 Then
X = -1
End If
SQL Statement :: Nearly Working Just Cant Get Form Values In Statement?
Aug 4, 2010I cant get this SQL statement to insert any of the values in the form to add to the database
sql
sql = "INSERT INTO prevresults (ExamDate, ExamTime, CorrectAnswers, PassPercentage) VALUES (date.now, time.now, rightanswers, percentage.text)"
[code]....
Return Statement Which Is True In An If Statement?
May 24, 2012Return statement which is true in an if statement
View 3 RepliesBreak Up The Code In A Method Body Into Statement By Statement Symbols/"tokens"?
Apr 22, 2011I'm writing something that will examine a function and rewrite that function in another language so basically if inside my function F1, i have this line of code var x=a.b(1) how do i break up the function body into symbols or "tokens"?I've searched around and thought that stuff in System.Reflection.MethodInfo.GetMethodBody would do the trick however that class doesn't seem to be able to have the capabilities to do what i want..dit 2:basically what I'm trying to do is to write a program in c#/vb and when i hit F5 a serializer function will (use reflection and) take the entire program (all the classes in that program) and serialize it into a single javascript file. of course javascript doesn't have the .net library so basically the C#/VB program will limit its use of classes to the .js library (which is a library written in c#/vb emulating the framework of javascript objects)
View 4 RepliesExceptions - Can The "Throw" Statement Exist In A Block With No Try/catch Statement
Oct 5, 2009how to use them then before, but am still a little confused with a few aspects. Here goes:
1.) Lets say you have a method that checks for a certain condition(s) and if it fails Throws an exception. Does it have to be in a try/catch block? Meaning can the "Throw" statement exist in a block with no try/catch statement?
2.) Now lets say we have a method that has a try catch block and in it there is a throw statement. When the throw statement is executed does it first try to find an appropriate catch block in the same method or does it immediately go back to the calling method without looking at the catch statements in the current method where the exception was thrown?
3.) I created a custom exception class that inherits from ApplicationException. Next I created a method which has a catch block that catches this type of exception and does some action. Is the System(i.e CLR) smart enough to throw an exception of this type, or does it only throw exceptions from SystemException?
4.) I know that some people are more liberal in their use of exceptions and others use it more sparingly when truly strange stuff happen like the DB going down. I am writing code where I am getting some info back from the database, converting it and then storing it. Sometimes there might be data that comes back from the database and other times the field is empty and the Null value comes back. Therefore in the instances where Null comes back from the database I should not convert the value to anything, since I will get an error. What should I do in this situation? Should I let the CLR throw the exception when it goes to convert the Null value or should I check for the Null value and if it exists not convert?
5.) In general when I throw exceptions, is it sensible to only throw exceptions of the type Application Exception or are there instances where the programmer throws exceptions of the type SystemException?
Make A 'like' Statement Or Use Some Kind Of Wildcard To Make The Statement Not Case Sensitive?
Jul 11, 2010I'm building a listview search feature in my app. (See the code below). It works really well, except if you search "T" then the code removes all items, if you search "t" then it removes every item except for those starting with "t". Is there any way to make a 'like' statement, or use some kind of wildcard to make the statement not case sensitive?
For Each itm As ListViewItem In ListView2.Items
If itm.Text Like TextBox1.Text & "*" Or itm.SubItems.Item(1).Text Like TextBox1.Text & "*" Then
Else
[code].....
"End Of Statement Expected" Error In VB 2010 In A Do While Statement?
May 2, 2012I have a line of code that is working in one statement but not the second statement. I'm not sure what I'm doing wrong, I am learning slowly but surely, and it is by no small margin because of the ave found here =) The error is occuring in the intResult = intSelection x intCount line of the SECOND Do While Loop.
The blue squiggle line is under "intCount" just FYI
Dim intSelection As Integer
Dim intCount As Integer = 0
[code]....
Components - "if" Statement Shows An Error " Statement Cannot Appear Outside Of A Method Body"
Jan 29, 2009I have the following vb code which works as expected when it's in a code-behind page. I tried to move it to a shared or component page since I will need to use it in multiple pages:
Imports Microsoft.VisualBasic
Public
Class DetTime
'Determine eastern time
[CODE]...
However the "if" statement shows an error " statement cannot appear outside of a method body" and the Microsoft solution is to "move statement into a procedure or subroutine"