Issue
I have a method that is used to check values to see if they are accepted by the DataType in the database column.
I have a list of values which will be added to the database and also a list of DataType's from the table they will be added to, and i want to make sure that when I run a Stored Procedure to add the values that the values are correct.
Code
Private Function CheckAllDataTypes(FormattedDate As String, sString As String(), file As FileInfo) As Boolean
Using dbConn As RgsDb2.DbConnection = DataConnections.DbConnection()
TableDataTypes = DataConnections.ExecuteQuery_SingleResultSetWithParams("sellTableDataTypes", dbConn, Params)
End Using
For Each item As String In sString
//I WANT TO COMPARE THE VALUES IN SSTRING TO TABLEDATATYPES.
Next
End Function
Example
So lets see the table columns that I am wanting to add to are int,varchar,varchar and the values in sString are 3,"testing",3.
This should fail as 3 is not a string.
Use a regex in your testing loop to check for numbers as strings if you don't want to consider them as a string.
Integers can be strings so you will also need to check for it being "alone" as it were. You might say that 3 should not be treated as a string but you would be hard pressed to say that "te5t1ng" shouldn't be treated 100% as a string.
Related
I have a series of percentage values saved in a database that look something like this:
Percentage
_____________
100.00000
50.00000
74.02500
When I display the values to the screen, I'd like to trim unnecessary zeroes from the end of the string along with the decimal point so the above examples become:
Percentage
_____________
100
50
74.025
I'm currently using the following code:
displayVal = rawVal.TrimEnd({"0"c, "."c})
but this code continues to trim after the decimal if there are additional zeroes. I also tried:
displayVal = rawVal.TrimEnd(New String({"0", "."}))
which almost works. It just leaves the decimal point.
Is there a way to do what I want using TrimEnd() or do I need to switch to regex?
As Tim already mentioned in the comments, if the data type in the DB is already some numerical type, it would be best to keep it in that type and then use the appropriate numeric formatting when converting it to a string for output. If, however, the input data is already a string, then that's not an option. In that cast, the simplest option is to just do two trims in series, like this:
Private Function RemoveUnecessaryZeros(input As String) As String
Return input.TrimEnd("0"c).TrimEnd("."c)
End Function
However, that doesn't give you a lot of flexibility, it doesn't remove preceding zeros, and it does nothing to reformat the string using the current culture. If that matters, you could instead parse the value into a numeric type and then use the desired string formatting options to re-output it to a string. For instance:
Private Function RemoveUnecessaryZeros(input As String) As String
Dim result As Double
If Double.TryParse(input, result) Then
Return result.ToString()
Else
Return input
End If
End Function
However, when you do it that way, you may potentially lose precision along the way, depending on the input numbers and the data type you choose to parse it with. If you need more control over the parsing/reformatting and you want to keep it purely in strings so no precision is lost, then you may want to consider using regex. For instance:
Private Function RemoveUnecessaryZeros(input As String) As String
Dim m As Match = Regex.Match(input, "[1-9]\d*(\.([1-9]|0+[1-9])+)?")
If m.Success Then
Return m.Value
Else
Return input
End If
End Function
Hi I'm wondering is there a way using sql to replace a string that contains a specific sub string with a new string on mass.
I can replace one string with another no problem(Find and Replace). However I have a situation where I need to replace thousands of lines where the strings are almost the same but not exactly. They all have a unique id appended to the end.I want to use the first part of the string which is the same for every line to identify the lines i want to change and replace the entire string with a new string which will not be unique across the table.
The following works in most databases:
update t
set col = newstring
where left(col, xxx) = identifierstring;
I think this is what you are describing.
I want to get two output values in one Function is't possible ?.
I am just using String data type and split the values.
but have any other easy way to get two output values...
Actually I want to checking a folder how many jpg files are Horizontal and vertical
so
Public Function HVChecking() as string
Dim HCount%, VCount%
''
''
''
''
Return HCount.ToString & "|" & VCount.ToString
End Function
finally I split the values with "|" character...
have any other options to get two values as separate in one functions.
I have no idea about Dictionary, HashTable... Which one is best for this?
I think you can send two ByRef Parameter to the Function. I mean,
Public Sub HVChecking(ByRef HCount as Integer, ByRef VCount as Integer)
And you can call the function as
Dim HCount%, VCount%
HVChecking(HCount, Vcount)
There are data types that exist in the framework to encapsulate two integers, Point immedaitely springs to mind.
If you wanted to add some context you could create your own Class or Structure.
As a last resort, or if you don't have time to type 4 lines, you could use ByRef parameters. These can give good performance but, they are the legacy approach for good reason.
Yesterday i had a look at how to set values of variables from nummbers stored in external txt files
the variables then needed to be added up so i used trial and error first
((XVAL) + (NEWVAL))
assuming that XVAL was set to 10 and NEWVAL was set to 20 i expected to get the answer of thirty but waqs presented with the new value of 10 20
VB.net pysicaly added the two values together but i wanted the mathematical product of the two which is ((10) + (20)) = 30
yep its a newb question could anyone explain how to achieve what im affter
XVAL and NEWVAL are strings, so they are simply being concatenated together. You need to convert them to integers, so that VB.NET will treat them as such. To do this, use the Int32.Parse() method.
Dim intXVAL As Integer = Int32.Parse(XVAL)
Dim intNEWVAL as Integer = Int32.Parse(NEWVAL)
Dim result = intXVAL + intNEWVAL
You want to cast them to a number first.
Try CDbl.
See http://msdn.microsoft.com/en-us/library/Aa263426 for more.
edit: Oops, thought you were talking about VBA.
Try using Double.Parse(YOURVALUE) if you're talking about VB.NET.
Have you tried the Val() function?
Val(XVAL) + Val(NEWVAL)
The + operator in VB.NET (for backwards-compatibility reasons) means both add and concatenate depending on the types of the variables it is being used with. With two numeric types (Integer, Single, Double, etc.), it adds the values together as you would expect. However, with String types, it concatenates the two strings.
Presumably, then, your XVAL and NEWVAL variables are String types because they're being read out of a text file, which is causing VB.NET to concatenate them into a new string instead of add them together. To get the behavior you're expecting, you need to convert them to numeric types.
Some of the other answers suggest casting simply casting the string values to numeric types (CInt, CSng, CDbl, etc.), but this may not work as expected if the value contained by your string cannot be converted to number. The Int32.Parse method will throw an exception if the value held by your string cannot be represented as a number. This is especially important to keep in mind if you're reading values from a text file that are not guaranteed to adhere to any particular constraints.
Instead, you probably want to use something like Int32.TryParse, which returns a Boolean value indicating whether or not the conversion succeeded and will not throw an exception.
As you are reading from a text file I assume that you are reading your values out as strings, so when you do this:
((XVAL) + (NEWVAL))
It is effectively concatenating the two strings together. In order to get the mathematical product of the two values these need to be int/integers which is the number type.
There are a number of ways you can do this, but in essence you have to 'cast' the strings to ints and then do your calculation.
So in vb.net it would be something like this (pseudo code):
Dim xval As String = "10"
Dim newval As String = "20"
Dim x As Integer = Int32.Parse(xval)
Dim n As Integer = Int32.Parse(newval)
Dim prod As Integer = x + n
Console.WriteLine(prod)
There are a number of other methods of doing this, for example using:
int.Parse(...)
or
Integer.TryParse(...)
More information on these sorts of type conversions can be found here:
http://dotnetperls.com/integer-parse-vbnet
One thing to bear in mind with these sorts of conversions is that you have to be certain that your input data is convertable. Otherwise your code will throw exceptions. This is where TryParse is useful as you can use this to check the inputs and handle invalid inputs without the need for exceptions.
In one of the ms-access table I work with we have a text field with a set size.
At the end of this field there is some extra code that varies depending on the situation.
I'm looking for a way to remove one of these code but even when the last part is truncated by the field maximum size.
Let's call the field "field" and the code I'm looking to remove "abc-longcode".
If I use the replace SQL function with the string abc-longcode the query will only work when the code is complete.
If I also want my update query (that does nothing but remove this specific code at the end of my field) to work on incomplete codes how would that translate into ms-SQL?
It would have to remove (or replace with "" to be precise) all of the following (example of course, not the real codes):
abc-longcode
abc-longcod
abc-longco
abc-longc
abc-long
abc-lon
abc-lo
abc-l
Obviously I could do that with several queries. Each one replacing one of the expected truncated codes... but it doesn't sound optimal.
Also, when the field is big enough to get all of the code, there can sometime be extra details at the end that I'll also want to keep so I cannot either just look for "abc-l" and delete everything that follows :\
This query (or queries if I can't find a better way) will be held directly into the .mdb database.
So while I can think of several ways to do this outside of a ms-sql query, it doesn't help me.
Any help?
Thanks.
You can write a custom VBA replace method that will replace any of the given cases {"abc-longcode", ... "abc-l"}. This is essentially the same tack as your "several queries" idea, except it would only be one query. My VBA is rusty, but something like:
public function ReplaceCodes(str as string) as string
dim returnString as string
returnString = str
returnString = replace(returnString,"abc-longcode","")
// ... etc...
ReplaceCodes = returnString
end function
I may have gotten the parameter order wrong on replace :)
I would use my own custom function to do this using the split function to get the first part of the string. You can then use that value in the update query.
Public Function FirstPart(thetext As String) As String
Dim ret As String
Dim arrSplitText As Variant
arrSplitText = Split(thetext, "-")
ret = arrSplitText(0)
FirstPart = ret
End Function
Can you use:
Left(FieldX,InStr(FieldX,"abc-")-1)
EDIT re Comment
If there is a space or other standard delimiter:
IIf(InStr(InStr(FieldX, "abc-"), FieldX, " ") = 0, Left(FieldX, InStr(FieldX, "abc-") - 1), Replace(FieldX, Mid(FieldX, InStr(FieldX, "abc-"), InStr(InStr(FieldX, "abc-"), FieldX, " ") - InStr(FieldX, "abc-")), ""))